BRI Helicopter Takeoff

This happens fairly regularly these days: a helicopter landing and then taking off from the BRI helipad. This is just the first time we've got a video of it from nearby Dove Street



It's never a good sign, but apparently it doesn't always mean that its a critical emergency: apparently the helicopter works well as a way of getting patients from places like Plymouth or Taunton to the BRI without having to worry about an ambulance getting stuck on the M5.


This though, April 21 2018, the Great Wiltshire Air Ambulance bringing someone in from Pewsey, Wilts, "Medical emergency, helicopter conveyed to hospital". Hope they are well and enjoying the quality rice pudding which the BRI serves up.

The next day the team was involved in "Diving incident, helicopter conveyed to Decompression Chamber", taking someone from Chepstow to Plymouth. Busy weekend.

It's good to be in a country which has free, functional health care and a helicopter to take people which need that care to a hospital which doesn't ask for money. And, hopefully, doesn't ask for your immigration status to see if you are on Theresa May's "approved list".

The Uber Dev Team just Killed Someone

A software development team at Uber just killed someone.

The Uber AV killing is going to go down in software development as one of the "things you must never do" examples up there with Therac-25 and various Flight Control System failures. The datasets and traces of the collision, will, along with all analysis, be reviewed, torn apart and rebuilt into some fairly brutal dissection of the entire software development process by the Association of Computing Machinery Risks Group, which is basically a documentation of fuckups of one form or another.


Without waiting for any analysis, police and others are already saying "it wasn't uber's fault". That's the wrong way to view it.

Better to try and categorise it

1. Uber's system made a mistake —one that can be fixed and so never repeated. Other AV manufacturers can also use the data from the collision to avoid it in their systems too. 
2. The collision was unavoidable given the action of the user and the general category of LIDAR-enabled Autonomous Vehicle.

Option 2 means we would now have make a choice. Do we consider the death-rate of AVs "Acceptable", or push for more to separate vulnerable road users from AVs. That could be banning AVs from cities "it's just too hard right now", or trying to do something banning pedestrians from walking around, requiring cyclists to have some beacon implanted in the bike and charged up on a regular basis to announce its presence, etc. That's the category of "admitting your tech can't do what was originally promised"

It is a lot better politically if it does turn out to be the uber team at fault. Or a least blame the driver for inadequate supervision.

How society and industry reacts to this, the first fully self-driving car killing will reflect on the decisions and priorities which society makes. It should be the duty of the software developers to be honest about the incident and open about whether it and similar events can be prevented in future.

Unlike all "human at the wheel" collisions, the actions of the uber car can be fully replicated: with the recorded sensor data from the car and the same version of the software, exactly the same set of actions can be expected. Therefore we can see where it failed.

Here is the list of places

1. Sensing: failure to detect the victim with the sensors available.
2. Interpretation: failure to recognise the victim
3. Anticipation: failure to anticipate their movements (and/or the vehicle's) and/or failure to conclude from the anticipated trajectories of pedestrian & vehicle that a collision is likely
4. Planning: failure to come up with a plan to avoid a collision
5. Execution: failure to execute a valid plan.

What do we think?

Sensing: Uber, like the Google/Waymo vehicle has LIDAR: light-frequency radar Works perfectly well at night, wider angle of view than a set of headlamps. Range? Unknown. These are the state-of-the-art in sensing, very expensive, and why Tesla are claiming "you can get by without them". LIDAR is what engineers believe is needed. Yet here it has failed. Does it have known failure conditions? Rain, snow, hail, probably fog and smoke too. Doesn't recognise glass. Presumably doesn't work into low-sun either. "It was dark and they had dark clothes on" is not an excuse. 

Intepretation: First realistic way things could have failed. 

Anticipation: Not a fast moving vehicle, a person crossing the road. No obvious unexpected movements. This should not have been hard. If it is: give up AVs now.

Planning: Fun one. After concluding that a collision is likely, the car has to come up with a set of actions (brake, swerve, brake+swerve, accelerate, sound horn, ...). None of these actions seem to have been attempted.

Execution: Car skids on rain/snow/oil; swerving to avoid one crash triggers a second, etc. No actions appear to have been executed, so unless the car computer couldn't communicate with the steering/engine/brakes. not a failure point.

We suspect then: interpretation and anticipation. Or the sensors got an echo but discarded it amongst all the other inputs it had to deal with in a limited time. That is "prioritisation". 

We humans make exactly the same mistakes all the time. mostly you get away with it. When you don't, well, it could be skid and a dent, or you can be sliding down the crash barrier in a motorway, passenger and driver both trying to keep that steering wheel straight, everyone in the car screaming thinking  they are all going to die. Such events happen with all too much regularity across the country. and generally, unless fatal, nobody gives a fuck. Now its done by software, it gets a lot of press. We shall have to see what the outcome is.

If it was a software/system error, then it can be fixed. Uber can add a new scenario to test their software on, even before running it in a real car, and the limited set of AV manufacturers (Waymo, GM, Ford, ...) can use the same data in qualifying their software. Everyone can learn from it and repeats can be avoided. 

That's if we want that, and it is avoidable. The alternative is blame the victim, exonerate the software, carry on promising a safe utopia, now qualified with "some people may still die". 

That's a major change, as it is accepting that death is inevitable in driving the way we don't accept it for trains and planes. We do make that distinction in cars today, but that's because we all believe that "we" don't make mistakes, or that personal freedom "right to drive across town" is better than safety for all.

This death is going to have to make us spell out our priorities.

For now though, let's add Elaine Herzberg to the list of people killed by cars. She is one of the few to get a mention beyond the local press. That doesn't make her death any better.

Bristol: Snow Day == Smug Day

It was pretty chaotic night out there. On the one hand: almost no traffic. On the other, an Audi A3  trying to get up a slight gradient and stuck wheelspinning. After about 15 minutes people start looking out the window thinking "maybe should help", after another five minutes they open their doors, get out and start pushing. Who says there is no camaraderie between passengers in Audi and the driver?

As the residents are all staring out the window "will they fucking get a move on", the passengers help turn the car round so its weights on the front axle, and it manages to get another 15 metres up the hill before being abandoned. Hopefully BCC have suspended overflights of RPZ enforcement drones for the next few days.

One of the wierdest things was the fact that everyone was driving well below the 20 mph limit. This completely throws off your decision making as you think "I'll wait until they get past before pulling out", and yet they take so long you think "I'll just pull out in front of them". It's the Audi/BMW driving experience on a push-bike.


All mini-roundabouts, give way signs and zebra crossings are suspended, and you can stop in the middle of the road to talk to people. Not different from normal, except now you have a better excuse when challenged than "fuck off"

We considered setting out to a nearby pub on the off-chance of getting snowed in and trapped for 2-3 days. But which one?

1. Duke of York: good pub, risk of being stuck with David Wilcox. Which is fine, except after 24h of cider drinking he becomes a barge evangelist. We don't care for barges and think the remaining waterways of the city would be best built over the way they did with the River Frome to give us the M32. Sooner they do this for the harbour, the better. In fact, we are surprised the WoEP haven't suggested that to Marvin, as it'll be more popular and easier to deliver than a metro.
2. Miners Arms: Thursday is Pub Night. Risk of a three day lock-in with pub quiz enthusiasts keeping on with the quizzes as something to do. Challenge of explaining to A&S Police how aforementioned pub quiz enthusiasts all ended up being killed messily with the kind of small nail clippers airport security love to confiscate.
3. Farm Pub: highest chance of becoming stranded, Doom Bar on draft, easiest to acquire locally curated ganja (we are told). 

Tough choice

Anyway, that was friday, what about today?

Rejoice! Today is a day is a great to be smug!

Because yes, those of us who have the equipment to get round can go round, offering smug advice to everyone trapped.

Drivers of 4x4s and SUVs

Landrover Defender drivers have it easy today: that rickety thing they've kept alive through trading bits on ebay can now be used to cruise round the city. Wearing wooly hats, fingerless gloves and warm clothes obviously, given that class of vehicles' heating system.

Urban SUV drivers have a similar option, but need to be careful. Today may be the day that you can finally justifying spending £15K on top of a practical car..

Do: drive round, nodding knowingly at other SUV drivers.

Don't: discover when you get to a hill that you only paid a £12K premium and so have the 2WD model.

Do: use engine braking on the descents. If your car is an automatic, time to work out how to put it into manual mode, or try the cruise control.

Don't: discover while driving down one of the steep hills in Totterdown or Cliftonwood that it doesn't make a difference between 2WD and 4WD when it comes to using the brakes. No winter tyres, sliding into parked cars screaming.

Owners of cars parked on hills

It's too late to move them unless you pay your neighbour with a landrover to tow them somewhere.

Do: sit by the window, looking at your car, camera in hand, ready to jump out and take pics of whichever 2WD SUV drives into the side.

Don't: own a car of any net value.

Mountain Bikers: 

Do: cycle round offering smug advice to people trying to drive up and down hills.

Don't: get off and help, admit that it doesn't work and then, while pedalling of shamefully, wipe out on a patch of ice.

Pedestrians:

Do: walk down the middle of the road. Its the only bit which will get gritted after all.

Don't: look at your phone while walking round. Not today.

Don't: walk round with your hands in your pockets, in case you need to put them down when you slide out.



Skiers
Do: get out the skis you've kept under the bed for a decade, carry them to some hill and ski down.
Don't: go on about it for years in any of the pubs our team members frequent We don't care, really.

Mid-life crisis mountaineers

We want to have a special call-out to mid-life-crisis mountaineers, the ones you see out in Gloucester Road or Southville of a weekend, wearing a down jacket branded with North Face, Patagonia or Mountain Equipment,

This is your chance to get out all the stuff you've bought from Taunton Leisure of Bedminster over the years and stomp round the city

Do: get out the most excessive bits of equipment you have in an arms race with all the other mid-life crisis mountaineers.

Do: walk around being smug, especially on the deepest snow parts of the pavement, rather than the middle of the road where it's clear.

Do: remember that if you wear crampons, walk with  your legs wide apart so you don't step on your own toes.

Do: talk to random strangers, casually dropping phrases like "hut-to-hut through the Haute Savoie Alps" and "New Zealand South Island trekking", or even better, "Everest Base Camp"

Don't: get out your stuff to discover that since you last went near any of those places the plastic boots have gone brittle and failed.

Us?

Well, with an equipment failure like that, its trapped in the Farm Pub. We just wish that skier would STFU or we'll have to start looking for those nail clippers

Dear Redland-based driver of Audi YS12ZPX

We've discussed before the concept of a "Redland Mum": a parent who is prepared to injure other road users in order to make sure that they get to school at pickup and dropoff time. It's why the ten minutes before the school gate close and open events are one of the hazardous times.

This video of a driver endangering a cyclist was taken at 15:00, in Redland, so meets many of the checklist items. You'd have to know their final destination to know if this was a genuine "Redland Mum school run", or just a "Redland Audi Driver in a hurry". We've included the letter the owner shall receive.

---

Dear Redland-based driver of Audi YS12ZPX

As promised, here's the video of you going by at a distance I didn't consider acceptable. And, as there was nobody oncoming to squeeze past, no justification at all other than selfish indifference.

Just because you are in a hurry does not justify endangering other Bristolians.

• All it would have taken would have been a small wobble on the bike for a collision. Which if it had occurred would have had adequate video recordings for any prosecution.
• The police are now cycling round the city, enforcing the 1.5m distance from the cyclist which they consider safe. "Careless Driving" is what they prosecute on, ~3 points and its impact on insurance premiums.
  
• Your actions reinforce the reputation that Audi drivers have for being selfish and dangerous.

You didn't even get anywhere, did you? You ended up at the traffic queue at the top of Redland hill. That's the one which is there every afternoon, so you should have been able to predict it.
Not only was I able to catch up, I had to wait at the zebra crossing for you to pull out.

Which comes round to the final point. Your actions were actually counterproductive, weren't they? An extra 50cm of clearance and you wouldn't have been held up at the crossing. Instead you were delayed when you clearly didn't want to be, and now have the video of your driving up online for all to see.

Please, give a little bit more clearance when you pass, maybe even be a bit more patient when trying to drive across the city. Dangerously passing someone just to get to the next traffic queue achieves nothing.

School runs, UK vs US

This is a 2003 photo of a 14 month child about to be towed four miles to kindergarten.

This is Corvallis, Oregon, a small US town where apart from a university there is ~fuck all. As a way of getting the child to school, the roads are quiet enough that it's much less stressful than in Bristol. Herel, you can never be sure someone has seen that trailer before they cut you up at a roundabout. Corvallis? It only has one roundabout and you can avoid it with ease.

You do not need to worry about the safety of your child when getting them to school by bike in a town like this.

Indeed, once they are a teenager you don't need to worry much about them on the back roads, unlike near Bristol, where outside town, "quiet" roads like Beggar's Bush Lane are viewed as opportunities of drivers to sprint. In Oregon, you can send your child ahead and not worry.

In contrast, in Bristol, you do worry about that school run.

You want to be in front of the child, to get the cars to stop at the roundabout. But also at the back, in case the threat comes from that direction. It's worse when they decide to cycle to school on their own, as worry about their journeys. It's a relief when they decide to start walking with their mates instead.

But journey to school and back is the only bit of their day you need to worry about.

In contrast, in the US, you worry about the safety of your child in the school. That town where nothing happened was 50 miles from Springfield, OR, where in 1998 one of the high school shootings now considered "small" took place. And its 110 miles north of Umpqua Community College where in 2015 someone killed ten staff and students.

In those sleepy middle-class US surburbs and towns, you cannot trust your children to be safe, because all it takes is one unstable person and a gun and their school ends up in the list of "US school killings"

Britain: we've had that tragedy in Dunblane: fix: no more handguns. Indeed, we have even allowed automatic rifles until an afternoon in Hungerford, thirty-one years ago.

Yet too many people in the US are unable to accept that such solutions "no guns" work, and all they are left with is trying to escalate it. Would you feel safer at school knowing all the teachers were armed? Not really.

Maybe, just maybe, this time, with the anger and voice of the children themselves, things may change.

#NeverAgain

I say we dust off and nuke them from orbit

The Alien series have gone from groundbreaking space-horror to a repetitive collection of cliches. They always start with the protagonist, Ripley —or a Ripley-substitute actress— innocently asleep in cryosleep, dreaming while the ships cross between the stars. A small blinking light by the frosted face is the sole sign of life.

And then something changes. A computer starts beeping. the light blinks a bit more, shadows cross the peaceful face of Ripley as she and her colleagues are awoken, once again, to defeat the Alien.

And it will be defeated: that much is a given.

The real variables are: what form does the final battle take? Whether technology, as represented by the android, is on the side of good or bad? Whether they've finally got around to redesigning space craft so as to have air vents too small for aliens to fit? And who will be the idiot who takes too close a look at "that funny egg thing".

With such a limited set of variables, the last few films in the series have been really, undeniably, repetitive. Everyone must wish that they put the series to bed, put Ripley in the cryochamber, shut down the android and walk away —because everyone is getting bored of it.

Which brings us to the council's latest plans for a metro line on the Bristol to Bath railway path.

Some people may be shocked by this, but others, we go "Again?" "Not again!". Not in fear, but in the tired despair of people who went through all of this a decade ago. Last time: thousands of people out celebrating victory over a council that had concluded that it was a stupid idea. This time, again, the council pays some consultants for some ideas on transport, and again, they say "oh look, there's a former railway line here", pointing to the BBRP, and again, it all kicks off.

Well, so be it. Right now the railwaypath.org has been in its cryosleep, costing $13/year to keep alive —much less than a sustrans membership.

And now, the console is beeping, the light flashing a little faster, and it's time to turn things on again.


What next? The monster will die, that much is a given. What is unknown is what order do the victims die —which councillor ends with the facehugger and who goes looking for the missing cat and ends up never being seen again?

We shall see. For now, we are just at the opening scene

beep. beep. beep. beep.

tip for the wise: motion detectors need a warning sticker "aliens may be in the air-vents"

Fixie Riders: don't Slipstream Mountain Bikes

It's January, and you can see who is out and about on their new fixie bike. This rear view video show our (expendable, tax-dodging) reporter turning off St Pauls Road, Clifton, onto Pembroke Road,
at a double-mini-roundabout put in to break Satnav. And coming up from the triangle, along Queen's Road, here comes someone in a shiny clean fixie, who decides to slipstream our reporter (expendable, tax-dodging).



This is where they a number of mistakes

1. Cycling behind someone on a bike without letting them know you are there. Risk: the rider in front might perform some manoeuvre without warning.
2. Cycling directly behind the bike, rather than off to one side, generally further from the pavement. Risk: you have to be able to stop as fast as the bike in front.
3. Cycling behind a mountain bike while you have a fixed wheel bike,
   albeit with a front brake.

We'll assume they were a bit drubbed from the climb and so didn't feel like passing, but they should have hung off to one side. At the very least, when they got behind our reporter (tax-dodging, expendable) they should have looked at the bike, and realised that it was a mountain bike.

In the video, you can see that the fixie rider (tax dodging, expendable, not so good at braking fast), gets to cycle behind the mountain bike until 00:30, when, in front of our reporter, someone on a phone steps out onto the zebra crossing. This puts our reporter into an aggressive-but-non-emergency brake. All well, until someone one a bike shoots up their left, almost into the aforementioned pedestrian. Which was a bit of a surprise.

It was only later, when the question "where did that rider come from", went through our reporters idle mind, that they went for the rear camera and had a look to see what happened. As you can see, they had their hands on the bars, drifted in right behind our camera, and, when the bike in front has to do that stop, nearly ride straight into the back of them, only avoiding it by swerving to the side.

Mountain bikers don't do chain gangs. They don't go along taking turns at the front, slipstreaming each other for performance, before hanging at the back to cycle no handed while you rummage in your back pocket for a gel with the same texture and flavour as baby food. Nor do they try and communicate with each other with little twitches of the hand, or pointing down and waving to say "there's something on the tarmac to avoid".

Instead they cycle along with enough of a gap between the rider in front so that they can see, enjoy and then learn from the mistakes the rider in front makes, rather than join in the crash. Food? Maybe, but they'll stop for that as they are generally lazy and view "cycling no hands" is one of the precursors to a trip to A&E. As for pointing out gravel, potholes or other surface hazards, those are not things to swerve around, they are there to jump over.

And, unlike fixie bikes with one front caliper brake, a modern MTB has hydraulic disk brakes, which, if the bubbles have been squeezed out of the cables, lets the rider bring the bike sliding to a halt with only the light touch of one finger on the brakes.

Because of that one-finger braking, mountain bikers are generally split into the "index finger faction": cycle with their index fingers on the brakes and the "middle finger faction", who use their middle finger. Whatever the choice, except on uphills, they're going to be cycling with their chosen finger on the brakes at all times. And when needed, they'll know to put that on, push their butt backwards to keep maximum weight on that rear wheel, with its 2.2+ inch surface on the ground, and so rather than skid, bring their bike to a halt faster than you could stop a British Leyland era Austin Mini (*).

When you come up behind a bike, see that its got wide tyres and disk brakes on the back, instead of cycling close enough to see whether the brakes are Shimano, SRAM or Hope, you need to think "this is a bike which can stop fast ridden by someone who may know how to use them", and not cycle right up their arse without even saying hello.



Do you know this rider? Are you that rider? Whoever it is: either hang off the side or stay back, especially to mountain bikes. Thanks

(*) MkI Minis had non-servo assisted drum brakes and to stop rear-wheel skid depended on that battery in the boot along with the WD-40, the hammer and the tow rope. As a safety feature, it was designed not to go very fast.

A Death on Brook Road

There's almost no coverage of Brook Road on this site, not because its out of our normal coverage area, but because nothing ever happens there. Apart from one incident where a manic van driver on a phone forced our reporter to jump off their bike and onto the pavement, nothing.

Which is why its so awful to hear that someone died here: Nick Graydon, age 27, died December 9 2017, after injuries sustained from a collision with a cyclist on Brook Rood who had apparently turned into Brook Road from Lower Cheltenham Road.

It happened at 8pm, which is of course dark.

Articles say "he stepped out from behind a van". Which is something we want to highlight, "stepping out from behind a van" is not exactly uncommon in Montpelier: it is also known as "walking around Montpelier". Because key feaatures of the area are vans, people walking, and pavements narrow to nonexistent. As an example, here's a continuation of the previous video, crossing Monty during the primary school run: count how many times somebody steps out from behind a van.

Like we said, we don't know the details. but "stepped out from behind a van" is one of those statements which pushes the blame onto the deceased, like "the cyclist swerved to avoid..."

Anyway, let's see what happens next after this, a tragic death which shocked everyone nearby.

No Elon, Serial Killers Drive

Elon Musk has been denouncing public transport. Clearly he too has tried in vain to get a FirstBus on a showcase bus route at Templemeads after the 22:09 Paddington train has come in at 00:30 on account of the electrification works diverting it south to warminster.

What's surprising is that his argument against public transport is "you could be sitting next to a serial killer"

We must disagree.

Key features of killing someone

• You are covered in blood and/or wearing some kind of butchers apron.
• You have instruments of death, like axes, swords and maces.
• You may have some firearm, which, even if you hide it in a ski tube, is still unwieldy.
• You have a body to dispose of. Maybe in a Deer Body Bag, but a body nonetheless.

Nobody will sit next to you like that, you will end up in a tube compartment or a bus to yourself, and before long someone in a uniform will sidle up saying "what's in the body bag, sir?". 

And that even excludes the problem of getting a bus in Bristol, which is always a bit sketchy, especially outside office hours. 

Serial Killers drive

In Bristol, a small hatchback is the vehicle of choice.

You've got a covered boot big enough to get a body in, low enough hatch that you don't have to lift the body with relative ease, especially if there are two of you. If they're big, you can fold down one of the seats.

Weapons, be they medieval maces or chainsaws, back seats. If they are covered in blood, again, a bin bag or two is handy, but on the way out you can just throw them in, maybe cover in a blanket for a bit of discretion.

That just leaves clothing which wipes down nicely, where some medieval-reproduction apron fills all the requirements of a butchers apron, but seems to get fewer looks when you queue for a flat white with an extra shot in the Leigh Woods cafe, before dragging the corpse off somewhere to bury.




Would we recommend a Tesla? It's got the luggage room, but it's too wide for inner bristol, too expensive for inner bristol and not discreet enough. A ten year old ford fiesta? Utterly unmemorable.

Could you imagine having to deal with a witness report saying "it was an old battered hatchback", and the police having to consider every owner of "an old battered hatchback" as a suspect? That's most car owners in the inner city. A Tesla, on the other hand, well, there's about four bold enough to leave Clifton, and when they do, they'll be on the Clifton Suspension Bridge camera, because if you can afford a Tesla, you can afford to pay £1 to use that bridge, rather than head through Cliftonwood to Hotwells and then over the Cumberland Basin Flyover. (though given the width of Granby Hill, you don't have much of a choice anyway).

There you have it. Serial Killers: battered hatchbacks, weapons on the back seats, body in the boot.

Public Transport. By inference. Not serial killers.

(These people were spotted getting together with similarly dressed and weaponed people in Leigh Woods late one Sunday Afternoon. Either they were going to re-enact bits of Game of Thrones, "It's my turn to be a White Walker!", or Highander. You'd have to wait and see if they started playing Queen's "It's a kind of magic" on some USB loudspeakers. to know which.)

Breaking: cyclists using bridge intended to be cycled over

Here is a video of someone trying to cycle from one side of the Avon to the other.

You can see at the beginning of the video that they have to  is another bridge, the cheesegrater bridge, which, since they replaced its artistic metal surface with one which works in the wet and ice, can be used year round. Or at least could be, if a lorry hadn't been driven over it, destroyed the surface and still, two months later, not been repaired.

Here's a video of someone cycling over it again


Nothing unusual there, given it has been since its inception a walking/cycling bridge

Why our coverage then? Because on December 5, 2017, Alex Ballinger, Bristol Post journalist, published an article Cyclists ignore signs asking them to dismount on a Bristol bridge but warning isn’t mandatory. Where, shockingly,

Pictures show cyclists riding over a city centre bridge and passing pedestrians

That is the most undercompelling subtitle you can imagine, but it gets filled up with

Cyclists have been photographed riding over a pedestrian bridge near Bristol city centre despite the ‘health and safety’ warning signs, but there is no way of enforcing the rule.

That's because its a cycling and walking bridge. There is no rule to enforce. The fact that the owners don't want to people to cycle over is their problem. The fact that the "cyclists cycle over the bridge" story is a recurrent on in the Post is, however, the newspaper's problem.

Here's an article from April 3, 2017, How many cyclists do you think we caught riding over a pedestrian bridge in Bristol in just five minutes?, by one Tim MacFarlan.

This is the Bridge in question. Notice how the recurrent videos of cycling over this bridge is, well, repetitive. Not a coincidence.



From the article

when it comes to a pedestrian bridge, with signs at either end ordering cyclists to dismount when crossing, you'd have thought you could relax a bit if you're on foot. 

Not so with the Valentine Bridge in Temple Quay if our experience is anything to go by.

...
This is despite the fact blue and white signs are clearly visible at both ends of the bridge saying in block capitals, 'CYCLISTS MUST DISMOUNT WHEN USING THE BRIDGE'. 

we filmed 22 cyclists crossing the bridge in both directions - and just SIX got off their bikes and walked across.

Well, it is a cycling bridge after all.

Except, guess what:

Not a single pedestrian complained to any of the cyclists, despite the fact they should only have been sharing the bridge with people on foot - wheeling their bikes if they had them.

The writer almost sounds disappointed "everyone on a walking/cycling bridge coexisted happily."

And here, May 10 2017, by Alex Ballinger, Sign urges cyclists to dismount on Bristol city centre bridge - but is it against the law to ignore it? This covers the Prince Street Bridge, but it quite clearly covers the fact that no, you can cycle where there's a "cyclists dismount" sign.

Now, that's a bit far back for some group memory, but there's search engines to find this history. And the article from October 23, 2017, These are the rules for cyclists. The clothes to wear, can you ride on pavements, and must you adhere to dismount signs?, by journalist Emma Flanagan.

Q. Do you have to adhere to dismount signs?
A. No. However, not dismounting can cause tension with pedestrians who may not be aware it is advisory.

And the article has a photo of guess, what? Valentine's Bridge.

That's the one in this video with the dismount sign next to a barrier installed without council permission. We think the barrier is designed to force people off their bike, but really its like chicanes are to Astra drivers showing off to their mates: entertainment. The challenge is "can you get round without putting a foot down". (tip: put the brakes on lightly but pedal all the way through; gives you a bit of oversteer and stops you having enter too fast).



There we go then: four articles this year on cycling over bridges with dismount signs, three covering this bridge, with the most overblown the "we counted 22 people cycling over a walking & cycling bridge and nobody minded".

The issue is no longer "why are these cyclists ignoring the signs", but "why does the local newspaper regurgitate same variants on the same story 4 times/year", especially when the story is "why do cyclists cycle over bridges designed to be cycled over?".

Some theories

1. Journalists are hard pressed to think up content, walking round Templemeads they see some people cycling over a bridge, see the dismount sign and think "that'd be something I could write up!", pushing out a story without bothering to search the archives or talk to colleagues.
2. Someone looks at the hit counts for previous articles and yells out, taps into the team whatsapp group, Slack channel or whatever "whose turn is it to do the cyclists on Valentine Bridge story this month?"
3. The bridge owners hate cyclists and every so often get in touch with the paper to say "we have a story!" And whoever writes it up doesn't bother to look through the archives. Or doesn't care.

We propose a sweepstake: when will the first 2018 article denouncing cyclists cycling over Valentine's Bridge appear in the Bristol Post?

Prize: a free cycle ride over the bridge

Rules: this competition is not open to Bristol Post staff or immediate family.

What's painful here, is not just the uninspired repetition of the same old story, a repetition which only increases prejudice and polarisation, but because we assume that the authors do have some ambition to really write compelling stories.

Yet there is an interesting one right in front of their eyes: the story about why a bridge built in the 21st century as a walking/cycling bridge has its owners trying to suppress cycling over it?

Here then, are our recommendations for the next Bristol Post journalist tasked with covering this story in April/May 2018.

1. Ask the bridge owners whether or not this was commissioned as a walking/cycling bridge?
2. Ask them why they unilaterally decided to add "cyclists dismount" signs?
3. Ask them why they unilaterally installed barriers without council permission?
4. Ask them why they get so worked up about cyclists exercising their legal right to cycle over the bridge?
5. Given the stance on cycling, do you consider that as a walking and cycling bridge, the bridge is a failure?

If the answers to Q2-4 is "because the bridge is too narrow", then ask them: what traffic modelling did they do? Was it wrong?  If so; why? If not: why was the bridge inadequate for the predicted numbers. And, if they didn't do any modelling, that's interesting too.

If the answers to Q2-4 are "because the surface is slippery when wet", ask them "was the weather of Bristol taken into account when the bridge was designed and materials specified"

Follow this with: given the surface of the first bridge was failure, why was the second crossing also designed with a surface which doesn't work in rain and ice?

A cycling bridge you cannot cycle over is not a cycling bridge: it is a failed project.

As, for Alex Ballinger and colleagues: why are you recycling this?

If you look at the comments, articles like this are clearly reinforcing the opinion of the commenters that "cyclists are lawbreakers". Maybe, but not here. This article has the defensibility of a "shocking expose, people driving on the M32 flyover". You should have been embarrassed to put your name to it

Please: write a new story on the failure of the bridge, not how Bristolians are using it as originally intended.

How does a big project fail? A day at a time

Bristol now has a new museum, Aerospace Bristol, which contains a documentary of the growth of the North Fringe Military-Industrial Complex, from WWI fighters to Polaris missile warheads.

It also has a monument to a classic project failure: Concorde.



Because, yes, Concorde is Bristol's most famous transport disaster. People admire the beauty of the plane, it's elegance, its unrivalled speed, but from a project perspective it failed.

1. It came in years late.
2. By the time it was ready, its economics had changed: the 1973 oil crisis had happened.
3. And it turned out that mass travel was more profitable than premium travel for the elite, and that 747s fulfilled the role.

It was a disaster, but now there is a museum for it, rather than rows of Concordes at every airport. Off the new urban sprawl area of North Filton, east of the empty life wasteland that the Cribbs Causeway consumption complex. Not even on the Waze maps —whose postcode lookup directs you into the parking area of a Ford dealer. And in the museum, a plane, along with the other great innovations of the city.

The question we have to ask is: will metrobus join it? While it's not internationally renowed as beautiful failure, it has the "Came in years late" item checked off. Leaving only relevance.

Big projects go wrong. More specifically, they go wrong more significantly, more dramatically and much more expensively than smaller projects. And, of course, the cost of the failure is bigger: the time wasted, the money wasted, the lives frittered away.

So how do big projects fail? A day at a time.

Often its early up-front time which gets wasted the most. That is, with a two year project, the first 6-12 months are the most frittered away. Why so?

Unclear goals/Nobody knows what the fuck they are doing.

When they do start focusing on a plan, and make progress, management usually change plans, not realising the cost. "You've not built anything yet". Software gets this all the time, because there's nothing tangible, but you look at civl engineering projects and you get the politicans deciding to reroute buses and trains "its not been built yet", not realising the penalty of such a decision. Its political whims like that which make public projects worse than private ones. You get whims, but spreadsheets can usually steer them back on course.

People are over-ambitious about what can be done and how it can be achieved.

People just don't realise how rapidly that time gets frittered away. One of the worst troublespots is when the engineers give management a time estimate "it will take 24-30 months if we start today", the managers only hear the "24" , then immediately apply it to the current time "March 2017" + 24 months = March 2019. Then they fuck about talking and finally give the go-ahead after six months, but still expect that "March 2019" deadline to be met.

In a project with a deadline 2+ years out, nobody worries up front about making efficient use of their time. It's extended "what do we do" meetings, people feel freedom to think up "creative and imaginative solutions" to satisfy themselves: personal aggrandisement of their great idea, fashion over a exciting new technology not yet been shown to work, but which suits the project so well. six months to ship and all that stuff has been junked as unworkable and the surviving team members are scrabbling for proven technology with low risk, while cutting back on all the extraneous features "bike paths", "Border between Northern Ireland and the Republic"

At the same time on trying to crank back on the deliverables, the team is cutting corners, usually on quality. Deliverables may be "done", but that's an "unreliable piece of junk done". Which amplifies the problem, as instead of focusing on future deliverables, everyone is pulled into firefighting the short term problems.

The "little details" put off turn out to be big problems

On a really large project, you also suffer from a postponement of examining the "little implementation details" of the project, which turn out not to be so little. The only reason you didn't know they weren't little is that you didn't look in enough detail.

Examples: Discovery you need more of a bridge over a railway line, that you need more tunnels through politically sensitive regions, that you failed to survey the soil your project will be built over, or that there's a border between the UK and EU country where closing it to through traffic will upset local people and cause them to potentially overreact.

There's also one project killer which can happen even if the goals were right and executed properly: by the time you release the goals are no longer relevant. Examples: Nokia's Symbian OS, Blackberry 10 OS.

What are the warning signs?

Failure to define goals, even as project progresses. If its 12 months in and nobody can clearly define the project, you aren't 12 months in. You have just wasted 12 months and your schedule is still going to be "24 months from today".

New requirements being added. This is often a consequence of the delay and attempting to keep up with a changing world. You announce you will be 12 months late and management say "OK, but here's a new change we'll expect to make up for it".

Missing checkpoints. You miss an early checkpoint and you don't catch up. It's gone. When the goals are finally met, work out how much extra time it took above scheduled as a fraction of of the allocated time. and then multiply the deadlines for the rest. Example: if an 8 week milestone is met in 10 weeks, that's a 25% overrun: multiply the entire schedule by 1.25.

Low quality of intermediate deliverables, What does get delivered sucks. This shows a focus on timelines over quality, and will come back to haunt you as quality will only get worse.

Departure of senior staff tasked with delivering it. Especially those with no emotional commitment to the project. Not the visionaries with their grand plans who came up with it, not the people at the bottom for which "it's just a job". It's the more senior people who see the impending trainwreck and think "I have better things to do".

"Unexpected" increases in cost estimates. One or more of: increasing of timeline, increasing staffing, discovery of details they handn't reallised would be so expensive. There's often been a bit of preallocated overrun for "contingency costs", but if that gets burned up early then there'll be need for more.

Rapid changes in the environment which the project is to be delivered. For Nokia and Blackberry, they were: Apple iPhone redefining what a handset was; Google Android saying "in exchange for us collecting personal data from all your users, here's a phone OS and software to compete with Apple"

Now, given these warning signs, the exercise for the readers is to pick one of the following list of projects and see if you can identify all those warning signs.

• Metrobus
• HS2
• Universal Credit
• HMRC customs software needed for brexit.
• Edinburgh Trams
• Brexit

Same fucking signs, every single one of them.

Now, how are such trainwrecks avoided?

In software projects, the general strategy is "don't do this". Big "ocean boiling" projects are very much things to steer absolutely clear of. One or two software consultancies do get involved in them, but they take lots of money and somehow always managed to avoid the blame. Of course, when you are the consultancy wing of one of the big four accounting firms and your colleagues are also the accountants for the company, they'll look out for you.

If you are doing something like this: never say "we're committed now". Just because you've spent lots doesn't mean that the project will work, whether spending more money and time is the correct action. Sometimes it's best to recognise that the world has changed, and the ongoing project isn't relevant. Stop it: focus on something tangible and relevant instead.

That''s just how to get out the hole. The best thing to do is: avoid getting into it.

In software, "agile" development means you do lots of smaller bits of work, with a release schedule of 2-6 weeks, with the goal being "every iteration is a release which puts something into people's hands". There's no more giant release any more, just lots of incremental ones, where features could be some new thing you can do with the code, or just "faster" and "more stable".

With everyone working to a short cycle, there's less of the "three years to go, let's design something grand over many meetings" work, instead pragmatic solutions to current problems. And with that solution in everyone's hands, you can see how it is used and adapt.

As the environment changes, you can adapt on the next iteration, rather than struggle to redefine the grand project -or worse, pretend that reality hasn't changed, and that your work remains relevant.

Ignoring Brexit "don't be so stupid", how does it apply to transport, especially in Bristol?

A key thing: say no to grand metrobus-scale projects. That's underground systems, tramlines, cable cars, etc. They may get everyone excited, but they're risky and not so likely to deliver the benefits promised. And until they ship: useless.

Bike paths, for all their controversy, can be rolled out fairly rapidly, and, if new ones are added adjacent to others, build up an incremental network. That doesn't hold if you just put random bits of paint down where it was least controversial. You do need to have some joined up thinking wth an overall goal "every minor release expands the connected bristol cycle network by 500 metres", and some longer term plans which can motivate people and help define what you are doing in the first place "a way to cycle from Templemeads to the Centre which doesn't abandon you just when it gets scary"

The same for things like footpaths, zebra crossings & c. Pick a mid-term goal "children can walk to school with safe crossings", and work on it by identifying the riskiest crossings, funding zebra crossings, making sure the light timings work, that everyone is stopping for them (i.e. have some police enforcing gloucester road red lights for cyclists on intermittent weekday mornings), that the actions of others aren't hindering things (i.e. have police & council enforcing keep clear and double yellow signs by schools on intermittent weekday mornings).

Roads? Well, what to do? You could present some grand vision of the harbour where the A370 Brunel Way crossing is replaced by something further west, but that will hit up against the pressure to preserve the suspension bridge area, the demand for some for more lanes, for others for fewer, etc. Really, it's not going to satisfy people, so why not look for smaller tactical benefits. At this point some people will be thinking "lets get rid of the bike lanes", but if you look hard, it's often people parked in bus lanes "just for a minute" which cause problems. Special callout: parents doing Colston School dropoff on Gloucester Road. London has embraced the red routes for the "really no parking" roads...yet we haven't. Is it time

Otherwise, well: is it time to consider, if not a congestion charge, a Nottingham-style office parking tax. You can drive through town for free, but you don't get free parking at work. That has the potential to be more transformational to our core than the RPZ has yet delivered. Best bit: you don't need any new bridges or motorway junctions.

To close then: Metrobus is checking the warning signs of classic big project fuckup. Which is obvious to all of us. And so is Brexit. As for the software it'll need, like that HMRC stuff. They have had their deadline pulled forward, the scale of their workload massively increased and still, a year from delivery, nobody know WTF its meant to be managing. Not a chance.

Volvo bug reports, issue #2; SMIDSY

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"Sorry Mate I Didn't See You", as uttered by driver to person they nearly just killed due to failure to properly observe/assess the environment so making a decision based on incomplete and invalid data. Saying "sorry mate" is a way to imply that it was something minor like "sorry I didn't open the door, I didn't see you there", rather than "sorry I almost added you to this years KSI statistics, but I didn't look or comprehend the situation properly".

In this instance the driver did actually seem pretty horrified that she'd nearly done it, and she wasn't on her phone. What could be the cause then, on a clear and quiet afternoon with no other distractions in sight?

Tyndall's Park Road; Highbury Vaults is at the end of it. Before they blocked off Woodland Road on the left side of the climb, you could drive straight over. That kept the road a lot more hazardous, as there'd be cars trying to sprint across. Here though, Woodland Road provides an escape route to the side, with the raised section of road some mild traffic calming of the main university halls of residence to study route for students on foot & bike.  Coming downhill would have been a serious issue.

The vehicle is on camera for 4s of visibility before pulling out, but she doesn't actually stop at the give way, just slow down for <1s and then continue. You have to consider whether the fact that the roads were so quiet got her thinking "these roads are empty" and failed to properly stop & assess the situation. Or she was only looking the right, pulled out and didn't do a second check to the left as she came around.

Complacency?

Volvo bug reports, issue #1: MGIF driver

Given some of the Volvo self driving car developers are ex colleagues of Bristol Traffic team members, we get to file bug reports. Not some directly accessible issue tracker where you get to file stuff like "XC90 driver nearly killed me" only for tech support to close as a "works as intended", but at least get to give them cues about how their land-barges get used and abused in the field. Here's one of this week's Volvos. Mid-afternoon, not rush hour but within range of school pickup times. Sunny days to treasure before the miserable season settles in.

First: "MGIF" , "Must Get In Front"

Definition: A driver who is focused on overtaking the bike without looking ahead to consider "What happens next?

In AI terminology a "planning horizon of 1", usually loses to any computerised chess/draughts player with a horizon >= 2 unless the latter is awful about assessing the value of all enumerated moves & countermoves.

In this instance,

1. the speed limit of the bridge and the rest of the city for the subsequent 1-2+ miles in any direction is 20 mph. You can see one of the signs at 0:01 in the video
2. the cyclist she chooses to pass is doing 19-20 mph, still accelerating in their underresponsive steel-framed MTB.
3. The car a safe stopping distance in front is also doing 20 mph
4. And it'll have to slow down once it gets to the end of the bridge due to the road there (i.e it's 100% predictable, irrespective of time of day & pedestrian/traffic numbers)
5. the oncoming cyclist is going 15 + mph

Which means that

(a) there's no defensible reason to pass the cyclist "I need to break the law to overtake a bike cycling at the speed limit to get behind the other vehicle going at the same speed before I get into the city proper and really have to slow down".

(b) she's failed to anticipate how long it will take to overtake the bike, even as she speeds up to 25-30.

(c) the closure rate with the oncoming cyclist becomes about 40-45 mph. If the oncoming roadie hadn't been keeping to the far left of the lane, there'd have been a collision.

Looking back at the footage, she's hanging back at the split to two lanes at the tolls to make a late-binding choice of which one to go through -a slight sign of impatience.  She takes the left one; the right hand one is occupied by an SUV whose driver can barely see over the wheel, which is why the cyclist chose to hang back and wait: didn't seem safe to go ahead. As the Volvo comes through fairly rapidly, it's probable she has one of the contactless cards which you top up with prepaid bridge crossing tokens; sign of a regular user. Given time of day, perhaps a resident of N. Somerset doing a late pickup of a child from somewhere in Clifton, someone who cannot afford to be held up by any vehicle doing the speed limit.

Now, what is he dev team planning w.r.t. oncoming collision avoidance, where it assesses oncoming velocity of the approaching vehicle, adds with its own and estimates time-to-impact, so perhaps suggesting some alternate actions? And what to suggest? There's the "massively accelerate, swing in hard and then brake" strategy, which is an extension of this drivers decision (and essentially a reward), the alternative is: brake, swing behind the cyclist they tried to pass, put it off. Which is safer, but not generally that common amongst "legacy" manual-drivers. There's some psychological "we're committed now" decision which interferes with the more rational "braking to survive is a good idea" strategy.

enjoy

P.S. UK DVLA now gives MOT history over time: https://www.check-mot.service.gov.uk ...you can see that GP05RZE used to be a 3K/y child seat equipped barge of Hendon, NW London, then over to bristol to do 15K/y. Where you can see from the repeated warnings "pitted/scored disks, front headlamp deterioration" that the owner doesn't actually do any maintenance. Probably not a good sign. Almost as bad as a MkI Golf GTi with the wheels coming off..

Don't expect any sympathy from the council

Maudlin Street, July 2017. In the background you can see some old bits of the BRI being knocked down and replaced with premium student accommodation.

In the foreground, you can see a car diagonally across a (contraflow) bike lane.

Tax-dodgers often complain that enforcement of the cycle lanes in the city is as observed as enforcement of anticorruption rules in the Trump cabinet; our dataset does imply this.

This is possibly the only vehicle we have ever seen in a bike lane to have actually earned a parking ticket. Indeed, there wasn't even an index category in the blog, "parking-ticket", until this moment.

What has brought radical change in enforcement about? Clearly, a full diagonal parking with your front sticking out in the car-lane-for-real-people qualifies for a yellow label on your windscreen. That's despite the fact that it's got a disabled parking permit and its only inconveniencing cyclists.

Except it's not parked is it? There's some disabled parking bays behind our photographer, and this car is backed up against the kerb exactly as you'd expect a car to end up if it slowly rolled down the hill and came to a halt without getting enough momentum to get up on the kerb and/or cause damage. Lucky for the owners there. Because instead of repairs they'll only have that parking ticket to argue over with the council.

No idea whatsoever

These are from mid sept, just some photos of some vehicles encountered on a traverse of the city, from Monty to the Triangle.

#1: Upper Cheltenham Place 16:02, September 9.


There's a car in the middle of the road; it's go belongings in the back including a childs seat. A PCSO is looking in it. Left hand side of the vehicle is pretty bashed up. No other vehicles "unusally" bashed. No skid/ABS marks. Other than the PCSO, nobody is paying any attention.

@2: Nugent Hill, 16:15, September 9.


A car is on the pavement/build-out on Nugent Hill. Both sides of the car are bashed, the gap between them suspiciously as wide as the gap between the two cast iron bollards just in front of the vehicle.

Again, nobody around. This one looks exactly what you'd get when you were parked on the hill, the handbrake wasn't on (+wheels not turned, engine not left in gear), and the car rolled down the hill. If that' the case, at least it didn't hut anyone or any other vehicle. Provided the engine hasn't been damaged/pushed into the passenger compartment, then the VW polo should already be up and running by now.

Overall then: the background hum of bodywork repairs which keeps the city alive.

Field repairs

Can we observe that this is least competent bit of wingmirror taping we have ever encountered in the city.



It's barely held on with sellotape, they haven't even bothered to rotate the mirror for better aerodynamics. This mirror doesn't stand a chance of surviving motorway speeds. Which means first trip up the M5 & they'll be in Michaelwood service station buying some emergency insulating tape and some scissors. Do you know how much insulating tape costs on service stations? Do you know how much insulating tape it needs to hold the driver side window up after a failure of the electric window mechanism? Too much. And yet its not easy to drive to Birmingham "gateway to the middle" while holding the window up with your hand. That's why you should always fix up your vehicle parts with insulating tape *before* you set off, and keep some spare in the back of the car as the long-journey kit, along with the WD-40 and the hammer.

This car and its field repairs? Not a chance. You'd be embarrassed to drive round the core inner city with mirror repairs that bad. It says "we care enough out our mirrors to want to preserve them" (weakness) and it says "we're not competent enough to tape them down". That is, unless the real issue was they got fed up with the noise it made swinging into the dorr, and did just enough to shut it up.

Ripping the thing off completely would have been the better option : "where we're going, we won't need wing-mirrors!". But no: the owner of this vehicle tried, just failed.

We should really have a ranking scheme for wing mirror repairs. We'll give this one; 1 out 5

BMW: please don't drive like utter wankers

As the arrogant self entitled owners of an Important Car for Important People, we recently received a communication from the manufacturer. Here it is, unabridged

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Dear BMW Owner

Due to the large number of people who have been killed recently by drivers —especially pedestrians and cyclists in hit-and-run incidents— the transport minister Jesse Norman has been in touch with us. He would like to pass on a message

"It’s great that driving has become so popular in recent years but we need to make sure that our road safety rules keep pace with this change.

"We have some laws that ensure that drivers who kill others are rarely punished, but, given recent cases, it is only right for us to look at whether dangerous drivers should face the consequences."

We at BMW would like to remind our drivers that all of us are representatives of the BMW family; whenever one of us drives like an utter wanker, we are all tarred in the brush of shame. We must strive to ensure that the badge of utter-wanker-driver continues to be held by Audi drivers alone.

Please, study the highway code, and remember that you should be prepared to stop at "Give Way" signs rather than slow down slightly. In particular, when joining a roundabout you are expected to yield to all users, including cyclists. The Highway code also covers other signs worth learning, what the orange light in traffic lightss, and the rules of zebra crossings.

The next time your BMW is due in for a scheduled service, please get in touch to attend one of our free "safe BMW driving" seminars, whose topics include:

1. Speed limits: what, why and how.
2. Indicators: the politer way to communicate.
3. Overtaking: when you shouldn't.

We also offer to recalibrate the speed warning to 90 mph —just ask the service team to lower it.


Finally, when on a motorway, please leave at least two metres difference between you and vehicle in front —even when an owner of Ford Fiesta has mistakenly pulled into the fast lane while only doing 75 mph. It's safer for everyone.

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There you have it. We'll try and drive better than others, and even explore the do-not-disturb option or our phones. We should be able to keep it up for a few weeks to see whether you can get used to it. Motorway speeds are probably going to be the tough one, given that even Corsa drivers will end up passing us —that's not what we paid for.

PS: Why are we getting email from Jaguar Land Rover Australia saying "Congratulations on the recent purchase of your Evoque, and welcome to Land Rover."? Some mistake surely.

Stopping distances experiment #2: The real world

Last week we discussed a (flawed) stopping distance experiment, where we argued that you cannot stop from 18 mph to 0 in 6.5 metres, no matter what the police claim. That's when you are prepared to halt and planning the exact moment to pull on the levers.

What does it a real emergency halt look like? It looks like this video. Taken about half an hour before the one of a BMW driving down a pavement to get past a traffic queue, for reference.

Here is what it looks like when someone runs out in front of you while you are freewheeling down a hill (Hampton Road, BS6). Speed? Let's assume 18-20 mph. You can hear from the noise of the (hope) hubs that there's no pedalling, so this is just a gentle 5-10 mph curve round the mini-roundabout-of-death, a few spins of a drivetrain in precisely the low gear you are always in when you come up the hill from the Arches, and then coasting, relying on gravity to do the work.

• 0:26 small kid runs out from some cars, looks like 3 parked car spaces away. Assume: 12-16 metres.
• No previous visibility, on account of the cars being bigger than him.
• 0:27 cyclist sees this and shouts "wooah!"
• 0:28 bike catches up with where kid was: he's run on to be with his friends. (Assuming 16 metres, that puts velocity at 29 km/h)
• 0:29 cyclist has now slowed down to the kids running-along-the road pace. Asks child to look. Child doesn't appear to hear them.

The entire incident is over within five seconds. There wasn't enough time to slow down before any collison would have occurred. Shouting and swerving while you slow down is all you have.

The gradient of the hill will have made stopping hard, and this wasn't the "prepared for emergency brake" setup of our previous experiment. This is real world going round the town with your hands on the tops of the levers, with gravity fighting the decelleration. The combination of the time to see and actually slow down puts the total stopping distance at something like 20 metres.

Brakingdistances.com says you for a car @ 30kmh/20mph on a -12% gradient you shoud expect 6m of thinking, 14m of stopping. Which seems consistent.

Now imagine that incident happens once a "Kim Brigg's law" is passed: a pedestrian crosses the road, cyclist > 12m away, travelling at 18-20 mph. Cyclist sees pedestrian, shouts out. Tries to veer to the side, hits the child instead. That would appear to be enough to get the mini roundabout reinstated as Bristol's Public Gallows, and your eviscerated remains left to hang for days as school parents block the roundabout in their Volvo XC90s. "Look at that cyclist, he deserved it. Now, why is this anti-car council stopping me from driving at 30, can't they see I'm late for school?"

Who is to blame here?

It's not the kid's fault he wanted to be with his friends, it's not his fault all the parked cars made him invisible until he ran out.

He didn't look. Maybe he was enthusiastic about wanting to be with his friends. Maybe he listened for a car, but didn't hear any engine, so carried on out. Children are like that: Enthusiasm is not a crime.

What did the cyclist do wrong? Well, that's a question. Is freewheeling down a hill at 18-20 mph speed limit "reckless"? "careless"? Wilful endangerment of themselves and others? The Crown Prosecution would probably argue that, while everyone from the Daily Mail to the BBC would use verbs like "plowed" and "flew" as they covered the trial. In which case: driving round the area at 20 mph, especially in a low-engine-noise vehicle (hybrid, electric) is probably even more wilful.

The one thing you can point to the cyclist and say is: you knew term time had just started, and there were other kids on the pavement. Therefore it was likely there'd be more chidren ahead. So maybe you should have braked all the way down that hill. But: no matter what speed you go down that hill on a bike. if there is a car going the same way, it'll be right behind you or trying to get past.

Which moves to a more controversial question: is 20 mph too high a speed during school start/finish times? Should we drop from 20 mph to 15 in areas near schools? For everyone, drivers and cyclists alike?

Stopping distance experiments part 1

The Charlie Allinston case has not only raised the issue that fixed wheel, chain-only-braking bikes seem unsuited for the urban environment, but that cyclists themselves are criminals.

This was shown by a Met office video demonstrating how a mountain bike could stop in three metres, while a fixed wheel bike took 12 metres. Which, from the public video, looks pretty dubious.

Ignoring the thinking distance aspect of the problem (to be covered another time), neither of those bikes appear to be doing 18 mph. Martin Porter asserts that with a maximum deceleration force of a bike of 0.3g before the rider goes over the front bars, any bike is slower to decelerate than a car (max force 0.5g). We don't know the exact values. What we do know from experience is

• It's the front brake which does most of the conversion of kinetic energy into heat
• As you brake, you go forwards
• The back wheel, without weight, goes into a skid
• And it always seems to happen faster on tyres with less contact area (narrow tyres, knobbly mountain bike tyres on tarmac, ...)

Mountain bikers will know that to avoid going over the bars on a hard brake or steep descent means sticking your bum out the back, which is partly why dropper posts are so popular: lower C of G, better control on the descent.

Returning to the Allinston case, the police stated that Charlie had 6.5m to stop, and that because a mountain bike could have stopped in 3, his removal of the front brake made him culpable. But: they haven't show the actual CCTV of of the collision, so we don't know exactly what happened

What we can do though, is do the experiment proposed by the People's Cycling Front of South Gloucestershire: try to stop from 18 mph in under two car lengths.

Here then is our summary:

1. an experienced road and mountain biker cannot stop a road bike with touring tyres in the distance of two parked cars and a 1m gap between them. 
2. You can bring the speed down to about 6.5-7.5 mph (update: see the bottom of the post)

Equipment: a team road bike, "roadkill", purchased for $800 in 2000 somewhere in Oregon, a US state which is now charging people a tax for doing so.

• Tyres: Continental Top Contact 700x28 touring tyres, tyres which focus on all weather control and braking over rolling resistance and speed. That is: their braking should be as good as you can expect from any road tyre of a similar diameter.
• brakes: front and rear Shimano 105 rim brakes (from 2000), cables redone 24 months ago, pads Shimano 105/Dura-ace/Ultegra inserts
• Wheels: Mavic rims, hope hubs, again 24 months old and no rim wear.
• Garmin bike computer to determine speed from the GPS constellation and display speed as part of preparation for braking

Overall then: the brakes and tyres aren't going to degrade performance compared to any other road bikes with rim brakes.

Experiment:

1. Flat, traffic free road with enough visibility of the southern sky that GPS signal will work (Trivia: US Navstar satellites never orbit  > 54 degrees north or south, so above the lake district getting a signal is harder; for Galileo details ask one of our local engineers)
2. Two family cars, a "normal" gap between them (nobody had problems fitting today).
3. Turn on the Garmin to record speeds.
4. From a distance down the road, bring bike up to 18 mph & then coast briefly.
5. As you reach the front of the first car, brake as hard as you can safely, arse out the back and down as learned over the years on the MTB.
6. At end of the two car lengths, see what your exit speed is.
7. Repeat a few times.

Not the most rigorous, but with speed numbers coming from 31 orbiting atomic clocks it's as good on the flat as anything else.

Results

1. Getting to 18 mph on the flat does actually require effort, if attempted over a short distance. (This may make cyclists reluctant to shed that speed)
2. Even with warning and planning, you can't stop a bike in 2.5 car lengths from 18 mph
3. You can get down to 6.5-7.5 mph

Conclusions

1. If the met police video released to the media was the one used in court, then the qualify of the experiment has to be contested.
2. As well as the choice of the reference "not a fixie bike" as a mountain/hybrid bike with what appears to be wide surface area road tyres, its not clear that they are doing 18 mph when they get to the marker points where deceleration is meant to commence.
3. If someone else can stop from 18 mph to 0 mph in 3 metres, we'd love to see it.
4. Given warning, you can get to 6-7 mph, which may lead to reduce risk/scope of injury.
5. Given that cycle/pedestrian collisions at what for on road speeds are "low", we shouldn't be doing any cycle-paint-on-pavement bike paths, as they are engineering in danger

It'd be nice to see the logs of the police instrumentation data from their experiments. In fact, its something a defence lawyer should have been demanding: "show us the hard data"

Someone should run Bristol Bike Week event "can you stop in 6.5 metres with and without advance warning", to see what other people can do.

2017-09-11 Update : there's a flaw in the experiment: the measured exit speed is inevitably going to overestimate the actual one on any attempt to decellerate in a few metres.

Velocity (Speed) is distance/time: (d1 - d0) / t

But: what is the sampling interval of bike speedos (GPS and on-wheel?).

1. Not clear from GPS (though looking at the GPX file would probably show it), but 
2. on a 700x28 wheel the circumference is ~2.1 metres. 
3. Therefore the magnet on the wheel will only send packet to the bike computer every 2.1m of travel. 
4. Therefore the minimum distance which can be used to measure velocity is 2.1m. 
5. 18 mph is ~29 kmh
6. which is ~8 m/s
7. If you are trying to come to a halt  from 8 m/s n 6-8 metres then that's only four revolutions of the wheel, so every revolution will have to include a lot of deceleration: 
8. Assuming constant deceleration you are going have  to enter that final wheel rotation in travelling 1/4 of your entry velocity
9. so: it's inevitable that the distance travelled in that final rotation is going to be "something" between the entry velocity and the exit one
10. which is what the bike computer will end up displaying: it will overestimate the actual value

All we can really say is "the bike was still moving 10 m after attempting to decelerate from 8 m/s to 0 m/s"

How to do it better? Well:

1. you could let go of the brakes after crossing your chosen endpoint, coast for a few wheel lengths and so give the computer a constant velocity to measure. 
2. with the sub-cm resolution promised by Galileo's premium channels and a receiver set to sample many times a second, you could build a fully accurate model of decleration
3. you do rigorously measure the total distance travelled, assume constant deceleration over the distance and then work backwards from there to infer your velocity at the 6.5 metre mark

Anyway, it's mostly moot due to the thinking time even before you reach for the brake levers. Followup on that in the week, this time with video data. Essentially: you don't react fast enough.

WN15UKX beats the school run queues

It's term time in the city, a so the morning rush hour is worse, and we've seen the return of the mid-afternoon one, seen here.

In order to get anywhere, you need "flexible and imaginative solutions" as our Brexit negotiators say.


Here the driver of WN15UKX finds it impossible to make progress without risking their wing mirrors.

Residents of the inner city know that having wing mirrors is a sign of weakness, but here the driver of WN15 UKX isn't going to let the fact they value their bodywork slow them down. Instead, a neat little nip up onto the pavement, a quick sprint at 14 mph down the pavement and they are on their way. Maybe he was late for child pickup. Because you wouldn't want your child to walk home: it isn't safe, not even on the pavements.

Its drivers like this which give us selfish wanker BMW owners a bad reputation.