G827YLA: redland mum

Hello, this is a note to the man driving the car G827YLA down Cotham Road at 08:48 on Monday December 14.

I don't think you read this blog. In fact, I don't think you pay any attention to anything other than the little bluetooth headset you had in your ear as you sat at the zebra crossing at the bottom, trying hard not to to make contact with a cyclist. Me.

However, at some point in the future, unless they destroy that car under the scrappage scheme, you are going to try selling that vehicle, and when it happens, whoever is thinking of buying it is going to type in the registration number into google, possibly with spaces, "G827 YLA" . And you know what's going to turn up? This article. The one that accuses you of being a redland mum.

As background, here is our definition of a redland mum: a parent who is in such a hurry to get their children to school that the lives of of any person on the road are unimportant. If there is a choice between the death of a pedestrian or a cyclist and pulling up on the "school no parking" area after 09:00, then somebody has to die.

I know this, because I am the cyclist you nearly ran over, the one who had stopped to let a mother and two children cross the road. I'm sorry I had to slow you down to let a family get to school, but since they were walking, they rely on generosity to get to school on time, and I was feeling generous. This area, outside Cotham Grammar, is a marked "please drive at 20" area, and those buildouts are to make it slightly easier to cross, to avoid having to run through parked cars. But the pedestrians still have to rely on vehicles stopping to let them across. Back when the build-outs were put in some people did ask for a zebra crossing, but it was turned down "nobody has died here yet". Well, you almost managed to get the criteria met today, didn't you, my little redland mum, the man driving the 1989 Toyota G827YLA.

I guess you were a bit surprised that after swerving round to overtake all us (without signalling, we note) and sprinting off down the hill, I did actually catch up with you. For some reason you didn't want to wind down the window, you just sat their looking surprised, muttering something into your phone, and unhappy at having to stop for all the students. No need to fear - we Bristol Cyclists don't believe in violence. It doesn't fix problems, it only creates more animosity. And we come out worse. I was just planning to get a video of you to stick up on the web site for what we do instead: public humiliation. But you got away, even as you went down Cotham Brow, trying to work out where you could go that the cyclist wouldn't catch up with you. To let you into a secret, I'd memorised your number at that point, there was nothing else to do. I let you go down Arley Hill. There you are, thinking "Oooh I got away from the angry cyclist", when in fact my goal had been achieved: you were now heading away from whichever school you were trying to get to, you would be stuck in the 9am Arley Hill traffic queue, and your children would be late. Your initial goal: get to school on time at the expense of a family and a cyclist would not be met.

Oh, and you are in the database. Forever. That's Google's BigTable, which, as they say themselves "is a distributed storage system for managing structured data that is designed to scale to a very large size: petabytes of data across thousands of commodity servers." By replicating facts "G827YLA is driven by a redland mum" across multiple datacentres, each with thousands of "commodity" x86 servers with IDE or SATA hard drives, BigTable's storage capacity is bigger than any database ever built before. By distributing those datacentres round the world: Mountain View, California, The Dalles, Oregon, Dublin, Singapore, BigTable won't just cope with an earthquake scale disaster, they'd even cope with something more dramatic, like a small Tunguska-class asteroid. It would take something big like another K/T Boundary Event or an accidental or intentional exchange of strategic armaments to take your registration number offline.

Which means when someone looks up the car registration, this article pops up. It could be you, it could be a friend, it could even be one of the kids you had in the back of the car who will then start snickering and call you a "redland mum" behind your back. It could maybe be the police if you try something like this again and it goes wrong, someone does end up injured, and they decide to do a checkup to see what anyone knows about the vehicle. Which means that this posting, accusing you of dangerous driving -not just to cyclists, but to pedestrians- will show up. You now, as they say "have a history."

Goodbye, or is it just au-revoir?

Mobile phones by hour of day, day of week

This is a pretty big image -it's the phones by hour by day table presented as a graph; every day appears side-by-side. Follow the link to see it at a resolution where it works.

Some immediate observations

• Nobody walks around between 0400 and 0600.
• The rest of the time, the streets are busy.
• Friday and Saturday night are when people stay out late -so late that Saturday and Sunday Mornings are peak hours beween 0000 and 0400.
• Weekday traffic peaks in the morning between 0700 and 1100. There's a quieter spot, a busy lunchtime, then another quiet spot. But not much in it -traffic throughout the day is fairly constant.
  
• Peak evening times - monday to thursday- are from 1500 to 1800
• Less people come past at that time on a Friday -instead traffic is higher later on in the day. Possibly going straight from work/study to enjoy themselves, coming back afterwards.
• Sat and Sun have later starts, but their mid-day traffic is on a par with weekday midday traffic
• Saturday and Sunday's traffic levels seem the most mathematically "normal": traffic goes up, peaks mid-afternoon, then declines. On weekdays, office/study/school hours interfere.
• Monday is the quietest. Less people out at in the early morning, less people on every hour.

More complex work would break it up by phone: identify who was returning; also do some grouping tricks to identify students by term times and then then see if their phones have a significant different grouping.

bluetooth device data

This is an alternate presentation of the data, split by hour by day. Here as a table for anyone planning on doing their own analysis -just paste it into a spreadsheet and create a chart. Citations welcome.

	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
0	19	38	27	47	50	79	107
1	16	34	33	30	43	72	76
2	6	50	15	23	16	49	72
3	3	14	2	11	15	29	45
4	7	12	7	12	9	23	18
5	12	15	15	21	13	20	8
6	57	61	72	59	47	21	16
7	150	180	168	191	188	39	24
8	227	274	261	245	255	78	28
9	179	227	217	261	237	155	54
10	156	211	193	220	225	166	82
11	182	206	218	200	244	173	121
12	213	259	243	232	236	206	146
13	200	243	255	244	235	239	172
14	193	227	237	238	239	220	203
15	252	283	287	311	308	195	228
16	263	297	263	325	291	229	182
17	291	353	329	319	290	220	155
18	183	224	232	245	207	199	143
19	128	167	182	215	209	187	115
20	94	105	147	140	147	170	79
21	87	110	126	94	123	95	85
22	68	84	95	93	102	109	80
23	58	73	78	74	116	103	35

Datamining the streets

This site is a documentary. Normally: photos and commentary, but today here's something different: 6 months worth of scanned Bluetooth devices from somewhere near the Highbury Vaults. This is the "Highbury Dataset". Which is legal to collect, provided you don't do things like take photographs at the same time as logging the phone "MAC addresses"; numbers that are phon- specific and not related to the SIM card or phone number.

The Bath Experiment implied that one adult in 6 had a phone that could be logged -a Bluetooth phone set to "allow others to see my phone", a phone set to be discoverable. That would be interesting if true, as there were just under 30K phones sightings, which maps to 180K adult pedestrians. Regardless of that, the relative numbers provide insight of their own.

Here's the spread over the week.

Sunday, least popular. Tuesday to Friday most. Less on a Monday. Assuming that a big weekday group is the commuter and students, there could also be a big evening group, in which case less people are going out on a Monday. Or less students go to lectures on an Monday.

More interestingly: breakdown by hour of day

Big rush after 0900 - students again? And look at that evening rush, peak visitors between 1600 and 1700, with a gradual drop off.
Breaking down by half hour slots would show more, then there is flagging which phones have already been seen the same day; this would let you identify who was heading back.

For the paranoid, this experiment is no longer live. Disable bluetooth to avoid participating in similar experiments. And do not feel fear -not from this. Central goverment's plans to track every phone call and email is far more invasive. This project, "Georgian", is a community police state. It also means that Bristol Traffic is rapidly becoming the holder of more accurate data than anyone else. We know who you are and where you are going -stop it.