Friday, 28 August 2015

Those pro-speed petitioners: do their opinions count? Not for 38% of them, no.

We've stated repeatedly we are Bristol's premier data-driven transport new outlet, compared with the evening post, which is driven by "what gets the most paper sales to our dying customer base" and "what generates the most page hits". Controversies involving parking, cyclists and speed zones hit all three.

Sadly, we don't have access to the BEP customer dataset or the details on commenters they extract from their linked-up google accounts. What we do have, however, is the python code needed to convert the published signatory list into a CSV file, with some extra flags to indicate whether or not the petitioner is in a 20 mph zone or not.

            20 mph ward  rest of BRS  CUBA    other 
Pro            920         305         116     201
Speeders      1552        3365        2289     705

As a graph, showing the numbers by area, things become more obvious

Of the speeders, 38% of them don't live in in Bristol. Which means they are, as far as Bristol elections are concerned, as relevant as residents of the Isle of Wight. They don't have a vote, all they have is a whine.

Looking at Bristol itself, we see a marked split between those people in wards with 20 MPH zones vs those which aren't.

Even though the pro-20 MPH petition is a fraction of the size of the speeder's one, it is not far off having 40% of the total petitioner count from the 20 MPH zones themselves.

This implies some things
  1. The people who get most worked about 20 MPH zones don't appear to live in them.
  2. Many of the people who get worked up about Bristol's 20 MPH zones don't even live in the city.
  3. They must live very unhappy lives.
  4. A lot of the people in the 20 zones seem pretty happy with the zones and their lives.
We'll collect some more data next week, and make up some new conclusions. Until then,  get out there and get some signatures for whichever petition you care about.


ChrisBritton said...
This comment has been removed by the author.
CE said...

I signed the petition.

I am a resident of Bristol.

I am a resident of a ward in Bristol that has 20mph zones.

I was never offered the chance to select my ward. I entered my full address including my postcode.

The e-petitions site does not show my ward. You therefore conclude that my signature is worthless.

How many other Bristol residents have signed the petition but been let down by the site?

Bristol Traffic said...

Chris: that's interesting -sounds like a bug in the council web site, at least in their postcode -> ward mapping. And it is potentially unfair to both sides, as yes, it will be treated as a not-even-in-CUBA petitioner.

1. Out of curiosity, what is the 6 digit postcode (BSX YZZ)? or at least the first bit? And the ward?

2. Has this surfaced on other petitions? Pick one at random to see. Grab some screen shots, and if it does, raise it with your local councillors.

3. Enter your postcode into the Ward finder. Does it show up there?

In the meantime, give us your name as listed in the petition & ward & we'll patch your details in our automated analysis code. Same for anyone else with this problem.

Bristol Traffic said...

Deleted comment was

> So I don't count because I don't LIVE in a 20mph zone, despite the fact that I spend 90% of my commute in 20mph zones, and live just a mile away from them.

The clearly article states that if you don't live in the city, you don't count electorally. Why east bristol is out of the city is an issue to address at a bigger scale than this petition.

> You're clearly showing your bias by stating people who don't like 20 are living unhappy lives.

1. Maybe, but as the petition devolves into a rant against GF, it does come over as unhappy.

2. we have never made any claims towards impartiality.

3. Notice, furthermore, the use of "implies". That's an important term from a statistical perspective. We aren't concluding, merely saying "the data points this way".

> Nice and balanced report, good work. I'm sure you're proud.

As proud as the BEP reporters presumably are with their coverage of this and the RPZ.

> I can make generalisations too - if we remove the Kia, Honda Jazz and Hyundai drivers, I bet that the majority of people (At least 75%) will be in favour of going back to 30 zones.

Sorry, needs some data here. You are just stating opinions without any backing at all. If both surveys asked about vehicle ownership & use, then perhaps something could be drawn here. Otherwise, no.

> Oh, and guess what - I'm a cyclist, so I expect you think I should be in favour of 20 zones as well!