http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: New Ian walker study en Mon, 18 May 2026 22:20:47 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=11715&page=2#post-135369 Tue, 03 Dec 2013 13:34:16 +0000 gembo 135369@http://citycyclingedinburgh.info/bbpress/ <p>Thanks slow coach, that is what I was saying up-thread - POLITE works on a horse as combined with e yellow bib and helmet it makes the rider look like mounted polis </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715&page=2#post-135368 Tue, 03 Dec 2013 13:32:01 +0000 Dave 135368@http://citycyclingedinburgh.info/bbpress/ <p>Hmm, I see we cross-posted a very similar final paragraph! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715&page=2#post-135365 Tue, 03 Dec 2013 13:30:56 +0000 Dave 135365@http://citycyclingedinburgh.info/bbpress/ <p><em>We don't know how often cars don't pass but we do know that with a rider latitude of 30cm, we're going to comment on variation in the mean passing distance of +/-4cm and think of that as a function of the rider's clothing and not their distance from the kerb.</em></p> <p>Presumably the idea is that the rider wasn't systematically at a different distance from the kerb in each outfit, so with a reasonable number of data points it should cancel out.</p> <p>However, I'm not so sure. Anecdotally the test rider found drivers to be hostile to some outfits relative to others. I find it a little difficult to imagine that their riding wasn't systematically different (more intimidation = closer to the kerb?) which would skew the measured results?</p> <p>It would be interesting to know if, for instance, drivers held back for the novice, although they didn't give any more distance when they did pass. Not sure how you'd measure that though. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715&page=2#post-135364 Tue, 03 Dec 2013 13:27:25 +0000 Instography 135364@http://citycyclingedinburgh.info/bbpress/ <p>I suppose I was thinking that there's more to a pass than just the distance between the bike and the vehicle. The clothing might be influencing but the road conditions, especially oncoming traffic, so heavily constrain the available distance that can be given that to rely on it as the sole variable gives a really partial picture.</p> <p>Not sure how you would measure it in technical terms but what I'd be interested in are things like:</p> <p>* where they passed: on a bend, into oncoming traffic on a clear road etc<br /> * speed moderation: did the vehicle reduce speed before the pass<br /> * waiting: did the vehicle wait behind the bike before passing<br /> * stand-off: the distance between the vehicle and the bike during any waiting<br /> * the speed of the pass: There's a world of difference between a fast and close pass and a slow and close pass. </p> <p>So you might find, for instance, that the novice costume has more slowing down, waiting, greater stand off, and slower passing whereas the racer gets little change in speed and no waiting. But no difference in passing distance. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715&page=2#post-135338 Tue, 03 Dec 2013 11:02:00 +0000 steveo 135338@http://citycyclingedinburgh.info/bbpress/ <p>So what we'd need is a few radar detectors, one to record distance from the kerb, one to record the position of vehicles to the rear and one to record the distance of on coming traffic to calculate whether there was a gap combined with the rear detector to decide whether A) the pass was "safe" and B) how much room was given? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135324 Tue, 03 Dec 2013 10:25:00 +0000 amir 135324@http://citycyclingedinburgh.info/bbpress/ <p>I can't be bothered to read the paper at the moment - too much like my job. But what Instography points out may undermine the comparison between years that roadCC picked up on. If the study hasn't been done in a similar way to the previous study, taking a similar cross-section of roads, then there will be confounding. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135321 Tue, 03 Dec 2013 10:18:08 +0000 Instography 135321@http://citycyclingedinburgh.info/bbpress/ <p>The rider is passed roughly 100 times on each journey which suggests to me these are pretty busy roads. The rider is recording passes when they are between 0.5 and 0.8m from the kerb, which gives them latitude of 30cm.</p> <p>The roads are busy so the drivers will often be passing against oncoming traffic - their scope for extending the gap is heavily constrained by the need to avoid smashing into an oncoming car.</p> <p>We don't know how often cars don't pass but we do know that with a rider latitude of 30cm, we're going to comment on variation in the mean passing distance of +/-4cm and think of that as a function of the rider's clothing and not their distance from the kerb. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135313 Tue, 03 Dec 2013 09:45:45 +0000 slowcoach 135313@http://citycyclingedinburgh.info/bbpress/ <p>Amir - thanks for posting link for more details.</p> <p>Gembo the "Police" version had the widest berth, the "Polite" version had the narrowest. The difference in the gear was more than just one letter (T or C), so it wasn't (just?) that drivers could see that one letter different and change the passing distance as a result. The "Police" version had blue printing (more like real police?) but the "Polite" version had black printing. If drivers were able to read the messages they might have seen that these were different too "POLICEwitness.com – move over<br /> – camera cyclist" or "POLITE notice – please slow down".<br /> As Roibeard says "That's a statistician's "significantly", the average distance was increased by 4-8cm (to 122cm)" Maybe we need to know why some drivers passed so much closer than the average, so there is more research needed into other factors? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135299 Mon, 02 Dec 2013 20:52:28 +0000 gembo 135299@http://citycyclingedinburgh.info/bbpress/ <p>Fair bit of going beyond the data in some of Ian walker's studies, but only really in the conclusions</p> <p>He can produce more robust findings e.g. Man in long blond wig gets given wider berth than others. Person cycling with POLICE/ POLITE gets wider berth</p> <p>It is more complicated when you get to the bit where you then have a rationale linked to people wearing kit who get a narrower berth and why this might be?</p> <p>The blonde wig man and the POLICE/POLITE data remain compelling ie motorists can differentiate if the visual cue is strong enough e.g. Long blonde wig man or POLICE/POLITE notice but do not differentiate with more subtle or distributed cues such as hi-viz kit? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135275 Mon, 02 Dec 2013 15:43:55 +0000 chdot 135275@http://citycyclingedinburgh.info/bbpress/ <p>"they've clearly got some mental process going on to determine who is worthy of respect on the road or not"</p> <p>Perhaps, but it think part of the rationale - and I think the conclusion of the original study - is the 'assumption' that people on bikes 'with all the gear' are likely to be more experienced, less likely to wobble, able to bunnyhop tram tracks -</p> <p>or something. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135273 Mon, 02 Dec 2013 15:26:18 +0000 fimm 135273@http://citycyclingedinburgh.info/bbpress/ <p>Yes, punishment passes... what exactly is going on the the mind of someone who uses their car to try to intimidate another road user, regardless of what they have done? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135272 Mon, 02 Dec 2013 15:16:26 +0000 allebong 135272@http://citycyclingedinburgh.info/bbpress/ <p>I recall a few times when an aggressive, engine-revving, close-passing driver suddenly and miraculously turns into a sedate and gentle creature upon sight of a police car or officer. Amazing.</p> <p>As far as anecdotes go I do feel I get less room when on the road bike (jersey, lycra, helmet) than when cruising on the town hybrid (bare head, casual clothes). Emphasis on 'less' as opposed to none - there's always going to be someone who's going to close pass no matter what. </p> <p>In fact, thinking about this....someone who close passes everyone on a bike is at least consistent and is most likely to be an inconsiderate driver all round rather than specifically singling out bikes. But people who will close pass some bikes over others, while being an otherwise reasonable driver, that's worrying as they've clearly got some mental process going on to determine who is worthy of respect on the road or not. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135268 Mon, 02 Dec 2013 14:47:38 +0000 Instography 135268@http://citycyclingedinburgh.info/bbpress/ <p>"Which suggests most drivers know their driving is dangerous and intimidating. "</p> <p>Or that they are ultra-cautious around police officers. Or both. When you see people too timid to overtake a police car travelling at 10mph under the limit, you suspect ultra-caution. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135257 Mon, 02 Dec 2013 14:07:58 +0000 steveo 135257@http://citycyclingedinburgh.info/bbpress/ <p>Dave, I'd considered building one too but my current commute is largely trouble free*</p> <p>*looks manically for some wood to touch**...</p> <p>**Quiet at the back. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135254 Mon, 02 Dec 2013 13:56:31 +0000 Min 135254@http://citycyclingedinburgh.info/bbpress/ <p><em>It's interesting that drivers gave most space to the POLICEwitness.com video vest, but *least* to the POLITE vest.</em></p> <p>Riders also reported subjectively feeling less safe and getting more radge behaviour from drivers in the POLITE vest. Fits with my own observation that some drivers are willing to use their vehicles to punish cyclists who are wearing an outfit they disapprove of. Of course what some people may disapprove of will be different to others.. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135250 Mon, 02 Dec 2013 13:51:22 +0000 Dave 135250@http://citycyclingedinburgh.info/bbpress/ <p>I recommend the link immediately above for the full skinny.</p> <p>It's interesting that drivers gave most space to the POLICEwitness.com video vest, but *least* to the POLITE vest.</p> <p>For a hundred eurobucks it's tempting to put together a CCE sensor, although my commute is now pretty poorly suited to collecting data. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135244 Mon, 02 Dec 2013 13:27:35 +0000 gibbo 135244@http://citycyclingedinburgh.info/bbpress/ <p><em>No diff in how close they were except one with 'police' on it.</em></p> <p>Which tells us that drivers are willing to do things to cyclists they wouldn't dare do to a police cyclist.</p> <p>Which suggests most drivers know their driving is dangerous and intimidating. </p> <p>A pretty accurate reflection of the state of driving in the UK. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135241 Mon, 02 Dec 2013 13:07:55 +0000 amir 135241@http://citycyclingedinburgh.info/bbpress/ <p>There's a prepub at</p> <p><a href="http://opus.bath.ac.uk/37890/1/Walker_2013.pdf" rel="nofollow">http://opus.bath.ac.uk/37890/1/Walker_2013.pdf</a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135237 Mon, 02 Dec 2013 12:44:52 +0000 Instography 135237@http://citycyclingedinburgh.info/bbpress/ <p>Is it possible to read it without paying $41.95?</p> <p>It would be interesting to see how the bike is placed in the road and how much room there is for overtaking, if that's recorded. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135209 Mon, 02 Dec 2013 10:42:12 +0000 Min 135209@http://citycyclingedinburgh.info/bbpress/ <p>TWO FEET!</p> <p>Yes it certainly is. Depressing. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-135207 Mon, 02 Dec 2013 10:38:35 +0000 amir 135207@http://citycyclingedinburgh.info/bbpress/ <p>Reading the <a href="http://road.cc/content/news/99660-high-vis-clothing-doesnt-make-cars-pass-you-more-safely-says-new-study">road cc account</a>, I found this alarming:</p> <p>"Researchers from the University of Bath and Brunel University found that no matter what clothing a cyclist wears, around 1-2% of drivers will pass dangerously close when overtaking. They also found that compared to Transport Research Laboratory findings in 1979, drivers today on average pass 61cm (2ft) closer to cyclists - 118cm compared to 179cm."</p> <p>I haven't read the paper to see how comparable the studies are but, if the comparison is valid, this is a damning indictment on driving standards. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134762 Wed, 27 Nov 2013 12:17:09 +0000 Roibeard 134762@http://citycyclingedinburgh.info/bbpress/ <p>The study shows that the <a href="http://www.policewitness.com/vests/">Policewitness</a> high viz vest significantly increased passing distances.</p> <p>That's a statistician's "significantly", the average distance was increased by 4-8cm (to 122cm). That difference, although statistically significant, is less than the deviation in travel required to avoid a typical pothole.</p> <p>So there's nothing found in the study to practically (as opposed to statistically) increase passing distances.</p> <p>Hi-viz might make you more visible but doesn't make the driver any more courteous.</p> <p>Worse still, the second driver overtaking, following the first driver, gets closer (by an inch or so)...</p> <p>Robert </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134568 Tue, 26 Nov 2013 12:00:30 +0000 EddieD 134568@http://citycyclingedinburgh.info/bbpress/ <p>The threads on POLITE bibs on police forums are roughly the same as helmet threads on bike forums. I wasn't sure of the legality of said bibs, and did some googling. The debates fair brightened my morning. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134548 Tue, 26 Nov 2013 10:47:40 +0000 kaputnik 134548@http://citycyclingedinburgh.info/bbpress/ <p>I have a retroreflective headband in Sillitoe Tartan. I've often wondered if it might be confused (in my favour)for a police helmet. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134531 Tue, 26 Nov 2013 08:28:50 +0000 gembo 134531@http://citycyclingedinburgh.info/bbpress/ <p>Ron Mael, from Sparks was in Taggart? I missed that.</p> <p>All the horsewomen and the horseman of Balerno wear yellow hi viz and POLITE bibs. You definitely do a double take even when you know it is fake, well I do as I have been in the presence of policemen and policewomen on horses at demos and football matches.</p> <p>For POLITE to work on a bike you would need to look like the polis bikers not just the bib?</p> <p>With stats it is of course possible to find results you are seeking if your sample is big enough. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134516 Tue, 26 Nov 2013 00:09:36 +0000 wee folding bike 134516@http://citycyclingedinburgh.info/bbpress/ <p>Is he allowed to use Police?</p> <p>I thought the fake ones said Polite.</p> <p>OTOH I've long wondered how TV shows get to drive around in "Police" cars. I saw Taggart being shot once and the panda cars were on a transporter.</p> <p>I was that close to Ron Mael. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134489 Mon, 25 Nov 2013 19:45:22 +0000 Kim 134489@http://citycyclingedinburgh.info/bbpress/ <p>He has a discussing on whether wear Hi-viz makes any significant difference on driver behaviour and concludes that it doesn't. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134484 Mon, 25 Nov 2013 19:13:46 +0000 cc 134484@http://citycyclingedinburgh.info/bbpress/ <p><em>I think one of the outfits consisted of 'normal' clothing. </em></p> <p>So it did, pardon me </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134482 Mon, 25 Nov 2013 18:46:48 +0000 crowriver 134482@http://citycyclingedinburgh.info/bbpress/ <p>Yes, interesting that his new one appears to contradict the 2006 study: or maybe not. He's basically saying if all else is equal, and we change one variable (clothing, rather than helmet/no helmet) it makes little difference to drivers' behaviour. </p> <p>Not his first study in 2006, however. From the article: "Earlier this year, Dr Ian Walker published research that said White Van drivers passed closer to cyclists than car drivers. The University of Bath academic has now used the same video and distance sensor technology to measure drivers' attitudes to women cyclists and cyclists wearing helmets." </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=11715#post-134481 Mon, 25 Nov 2013 18:21:12 +0000 chdot 134481@http://citycyclingedinburgh.info/bbpress/ <p>This is (probably) his first bike study -</p> <p><a href="http://www.bikebiz.com/news/read/want-to-be-bike-safe-don-a-wig-not-a-lid" rel="nofollow">http://www.bikebiz.com/news/read/want-to-be-bike-safe-don-a-wig-not-a-lid</a> </p>