Thursday, 1 December 2016

The Psychology of Overtaking and VE08NXK

There is surprisingly little literature available online on the topic of The Psychology of Overtaking.

One paper you can find dates from 1997, Overtaking Road-accidents: Differences in Manoeuvre as a Function of Driver Age, by Clarke et al, of Nottingham University

Without going into the details, in particular questioning whether there's enough information on the general population of drivers and overtakers to reach conclusions about age, it does contain a good introductory summary of past work.

One quote in particular stands out
Wilson and Greensmith (1983) returned to the theme of the ‘‘inertial driver’’ in their multivariate analysis of drivers’ accident status in relation to observed driving patterns, gender and exposure. They report that accident-involved drivers drive more quickly ‘‘...and move around continually (especially overtaking) in traffic’’. The typical inertial driver differs from his high-exposure accident-free counterpart, in that he seems unwilling to change speeds in response to conditions by using gear changes, deceleration or braking.
This is interesting, as it does document a common behaviour you encounter on a bike: the driver willing to endanger themselves and others rather than tap on the brakes.

Here is a classic example on Belmont Hill, N. Somerset




Although it's a sharp bend, the gradient of the hill means that you can see oncoming traffic, especially when they have their lights on in the late afternoon. Look up to the top right of the picture and you can see a car coming down the hill. Bear in mind, it is still daylight, there may be an unlit vehicle or cyclist, and they would not be visible.

The presence of the car hasn't stopped the van VE08NXK from choosing to overtake precisely at the corner, going round the bend on completely the wrong side of the road. Either they hadn't looked or they didn't care. The driver coming down the hill was distinctly unhappy.

It would be really interesting to see what the reasoning of the driver was here. We cannot but suspect that it would be a "the cyclist forced me to make a dangerous overtake" claim, when really it was a "I was unwilling to adjust my speed in any way". Maybe we shall find out, having just reported them to A&S police as part of "Grass a Driver week".

Monday, 28 November 2016

Grass a driver week: MK59USB, texting across a junction

Apparently some police forces in the country are now rolling out enforcement of driving too close to tax dodgers, maybe even section 59 ASB orders, which are interesting as there is a lower burden of proof. It doesn't impact penalties or insurance, simply threatens to take the car away.

We watch these experiments with trepidation.

Meanwhile, Bristol has a page to report incidents for their records alone.

This week we are conducting a small experiment to report a few dangerous drivers to this site, to see what happens. Expect followups if there are any results.


First, MK59USB on Tyndall's Park Road, crossing Whiteladies Road while reading their phone.



There are now pedestrian crossing lights on some of the arms of the junctions, specifically Tyndall's Park Road has a walk and ike one (a small dip in the kerb allows the bikes over); Whiteladies Road inbound also has green. These require left-turns to be restricted, which has long been a rule more ignored than observed. The council has recently done some raised corner sharpening; be interesting to see what's happening.

Where there is not any pedestrian crossing is on St Pauls Road —the Clifton Side— people run across when there is a gap, such as when vehicles heading inbound are waiting to turn right, and in that little gap between Whiteladies Road going read and TPR/St Pauls Road going green.

Which means this mercedes is about to head towards a junction where there are likely to be people sprinting across. Will they put down their phone?

No, is the answer, they keep on looking at it, going down to one-handed so they can hold the steering wheel with the other. About half way through the junction, they look up, notice the cyclist, and hold the phone down out of sight.

Interesting question: what would have happened if the tax-dodger hadn't been there?

The experiment begins, then, by filing this on the A&S police site, see how they react.

What about the full report an incident process? Too much hassle given its inevitable that nothing is going to happen. If they don't act when you go to the station with a CD of a video and a complaint, it's unlikely that they will react to a youtube URL.

Tuesday, 22 November 2016

Metrobus on the railwaypath? Again?

the West of England partnership, henceforth known as the Bringers of Woe, have a consultation on a transport vision for the future.

Key points
  1. More people are going to live in Bristol
  2. More people are going to live Weston Super Mare, despite evidence to the contrary.
  3. More people are going to live in middle of nowhere dormitory towns near bristol, and hold unrealistic expectations about being able to commute into the city 
So, they have come up with a vision. That's a sort of a value between "no idea whatsoever" and "have a clue". Interesting to read, and so derive goals not just of Bristol, but the Outer Wilderness

North Somerset doesn't want anyone cycling to Bristol. We knew that, but their map doesn't even show the existing Festival Way as "a strategic cycling route", let alone propose it actually continue the extra 1-2 miles to reach as Nailsea. Instead they want an uprated A38 and a few tens of millions making the M5 more dangerous by turning the hard shoulder off at peak hours. Most interestingly the A38 to go to the M5 in a new junction. It's not clear what that will do, but apparently "This corridor experiences severe congestion ". If that statements is true, then the adverts for the Junction 21 Enterprise Zone you see while wasting hours at passport checks at BRS are lies. The advert? "15 minutes to Bristol". The reality? Not a chance. Yet here we are, with North Somerset saying "good transport links" on the J21 site, yet "experiences severe congestion" in another. One of those two statements is false —and if its the advertising, someone may want to complain.



Suggest: N Somerset consider alternative transport options to sitting in a traffic jam on the M5, and be open about its issues in the J21 site.

South Bristol doesn't get a callout of its own, just coverage in Bath to Bristol corridor. There's a small problem here in that the key public transport route between the cities is the train —and central government have removed electrifying this stretch of line from their "vision". That is, not even on some random future deadline which they can postpone, it's an outright "we don't plan to do this". Which means that the one change which would have really improved carrying capacity on the line, reduced transit times and pollution from trains in the cities? Gone.



Saltford is promised a bypass.


They also discuss LRT -Tram- along "the A4 Corridor". That's an interesting term there, as it doesn't mean "Along the A4", it just means "along the Avon Valley". There are two other options there (ignoring tarmacing the river). There's the train line, and then there's the Bitton-Bath stretch of the Railway Path, the stretch which has the steam trainists practising their hobby on a weekend. Could this be time to reinstate steam trains between Bristol and Bath? Brunel would be proud —they didn't have electricity in his day, after all.

Suggest: residents of South Bristol may have transport issues of relevance too. Anyone who cycles in Bristol might want to look more closely at the LRT routing.

Avonmouth, Shirehampton and Clifton Villages



Still a vision of getting the Henbury train loop in; still a vision for some more stations. Gloucester Road to Filton  and beyond and Whiteladies Road/A4018 to Cribb's causeway down as Strategic Cycling Routes. We have no idea what that means, and suspect the WoEP don't either, other than it means "no need to care about it anywhere else". Not that being a strategic cycle route will stop anyone painting out the bike lane.

Other points
  1. "enhancements to the public realm". This is planner-speak for spending money on brickwork rather than functional transport systems.
  2. There's not a single mention or illustration, anywhere, of people walking other than the phrase "cycling-and-walking" where the money will be split and each group will get their half of a pavement which will now have a white line down the middle. Yet for the inner core of Bristol and Bath, walking is the primary transport option. (we have no idea what it is for W-s-M, it probably involves riding a goat). 
  3. Page 14, or "other charging mechanisms.". That's either a parking tax, Low Emission Zone tax, or a c-zone charge.
And finally, a look to the north east. That dashed green line? "Light Rail Transport —Route to be determined"


Unless you are going to build a tram line down up Fishponds road, there is only one place to put anything in there: the Bristol to Bath Railway Path.

The last time the WoEP wanted to put a bus down there, there was a mass uprising of inner Bristol, with some support from outside. Doe they really think things will have got better now? Do they not realise that killing the path for the sake of a slightly faster commute to/from Emerson's Green is going to be acceptable? Not a chance.

Suggest: recognise that the traffic volume, walking and cycling, down the BBRP is higher than any tram can achieve, and doesn't cost £2.6B. Council would be better off filing plans to run trams down there into the box of "stupid ideas we will pretend we never considered".

Tuesday, 8 November 2016

We say dust off and nuke the car from orbit

People have coming up to us recently and been asking questions on our apparent lack of driving. The recurrent queries are
  1. Why haven't we seen you parking badly?
  2. Why haven't we seen you driving badly?
  3. Why haven't you driven right behind us in the fast lane of the motorway at 90 mph, flashing your lights at us?
For reasons which may be covered in a future post, the Bristol Traffic Important Car for Important People has now been officially written off; the insurers of the Important Car for Important People providing a rental car until a settlement is reached. The answers to the question are thus:
  1. We have —just in a Vauxhall Corsa 1.4
  2. We have —just in a Vauxhall Corsa 1.4
  3. We can't, it's a Vauxhall Corsa 1.4
Here it is in all its glory, just after stocking up on marmite at Sainsbury's Brislington.


Compared to a team member's MkII Astra 1.4L of many decades ago, the Corsa isn't that bad for luggage room, but manages to be tangibly slower. All the weight of modern safety equipment like airbags and ABS, along with power steering, electric windows and the like have made for a vehicle which struggles to break the 20 mph limit. Our urban speedo watching is now one of looking down at the mph dial as it gets into the late teens, muttering "go on Corsa, you can do it!".

Unfortunately, free vehicle that it is, it comes with a fundamental flaw: a £500 insurance excess and undamaged bodywork. It has both wingmirrors and the alloy wheels lacking those scrapes which mark a car christened for use in urban Bristol.

It's not a matter of whether the car is going to end up with a wingmirror held up with duct tape, wheels documenting the kerb heights parked against, or graceful scrapes aquired on daily use. It's when. It even constrains parking choices: you start worrying in the night about what it will look like in the morning —that maybe you shouldn't have parked sticking out quite so much on that corner.

Accordingly, rather than await the day when the car is returned and a large bill for damage presented, the team decided to return the car early, and borrow a parent's '53 reg Peugot 307 HDi. The parent in question had a little medical incident in August, their car parked up since then. Taking it away from them should help get them used to the post-driving lifestyle, which, in Portsmouth, "city by the sea", means getting used to FirstBus coming by once an hour, except on Sundays, when it drops to "who knows"

Vehicle collected, successfully driven to Bristol. Compared to the Corsa, it's stable, and it's manual transmission and the minimal turbocharger give it a better 0-20 number —still not great for getting on the M32 from the secret Mina Road access point. With the changes there, you can't even be at 15 mph before you approach the merge point.

But it's stable, and pre-commissoned for abuse in an urban environment. All it needs is cleaning up, the parent being one of those who like to hoard things in their vehicle.

All goes well, the interior binned; time to go to the boot. Four cans of WD-40 and three de-icers seem overkill, but as a Glaswegian who used to own a Mini, the owner no doubt had picked up some habits they couldn't get rid of. That's not the issue though, the issue is what turns up once the boot contents are purged, and the layers underneath explored.


What's there? Moss large quantities of it. Enough that you have to look for David Attenborough and his camera crew.

And under the moss? Water. Large quantities of water.


The entire spare wheel compartment has about 2-3 cm of water in it. This is, well, unexpected, and best accompanied with the expression "What the fuck?"

Now, Pompey is a coastal town, and it could be that there have been some high tides flooding the streets —tides covered up by the Portsmouth Tourist Board. This is unlikely, as the loss of the city to climate change is something that UKIP would be highlighting as a positive outcome of climate change.

Discounting that, and deliberate human action, the other key hypothesis has "it's been collecting water from rain". With the car unused for a few weeks (this photo was taken early October), water could easily have seeped in to the stationary car.

Except: it's been a really dry Autumn. Has it really been long enough for the spare wheel bay to fill with water and plants to start growing?

No, this car has been collecting rainwater for some time.

For anyone with ageing parents, there's always the question "when should they stop driving?" You always hope that they stop before they end up in a serious crash, maybe just a small one involving a bollard where the police suggest politely to put away the car keys.

Maybe, just maybe, the fact that you've clearly been driving around not noticing the strange slushing sound coming from the back, or the odd fusty smell. One can but hope. That or bribe the garage doing the MoT to make sure the car fails.

The wealthy in society, the Camerons, the Rees-Moggs, they look forward to inheriting the family estate, what with its greenery and lakes.

Us: we fear the family hatchback.

Friday, 30 September 2016

Causes of Congestion in the Greater Bristol Area: hint: not 20 mph zones

What has made congestion in and around Bristol worse —for those people driving or sitting in buses?

Some people are saying it's common sense that it's the 20 mph limits, and that common sense beats data. No: thinking beats common sense.

we can argue about whether @georgeferguson_x did things to make traffic worse;

RPZs didn't; they add more passing places to the narrow roads, and if they discourage people from driving in, could reduced traffic levels.

20 mph a factor? Not given average weekday traffic speed. (Source: Waze)



One key point is that if the average speed in a road is 2-7 mph, as Stapleton Road is enjoying, then 20 mph is an unrealised dream. It's not the problem. Question is: what's causing that delay?

The main factor is the number of people choosing to drive. Evidence of this comes from looking at the M4 heading away from Bristol, which is going at 12 mph.



By choosing an away-from-city route we can avoid blaming metrobus related roadworks or buildup from urban congestion. There's none of : cyclists, bus stop buildouts, traffic lights or 20 mph to blame rather than accept the root cause of the traffic jam is the decision of you and others to get in the car that morning..



It's people driving places. Which may be correlated with population growth, and the growth of north fringe sprawl housing and offices. North Lockleaze, or, as it pretends to be, Chiswick Village? New. Those fields north of the A4174 by Emerson's Green? Houses you get to see from the M4. That's a change: more suburban housing, more people driving around the city.

Secondary factors to motor traffic in town:  junctions, buses stopping, vehicles turning right, cars parked where they shouldn't. All amplified by traffic volume: bigger queues, longer waits, more turning vehicles, more people "just parking for a minute" in a bus lane, so forcing the bus to try and pull out and increasing overall unhappiness.

Traffic lights? They have a worse (but fairer) throughput compared roundabouts; see Modeling Roundabout Traffic Flow as a Dynamic Fluid System (skip the pictures and look at the pics on P8-11, knowing that "flux" means "number of vehicles arriving per second"). Essentially, all of junctions overload, but two-lane roundabouts get the most through.However that paper assumes that you can get off the roundabout, which as we know at peak hours (Hello Bearpit! Hello St Pauls Roundabout!) doesn't hold. Furthermore by modelling traffic as an incompressible fluid, they miss out on the game-theoretic aspects of the problem, as in: why you'd pull out in front of other vehicles, even if you know it will block others.

Because one problem roundabouts and traffic lights both have is people blocking junctions, so stopping cross traffic getting through. If anyone has evidence of yellow-hash do-not-block zones ever being enforced, we'd love to see it. We lack that evidence. What we do believe is that it would reduce junction deadlocks and so boost cross traffic. Again, evidence would be good. Perhaps the council could run an experiment —like enforcing the law for a week.

Fast moving cyclists? Nope. They just go past the queues and have an average speed above cars at peak hours. This clearly upsets some people who resent the fact that they have to drive a Fiesta 1.1L up the A38. We would hate driving a Fiesta 1.1L too, even on an empty road.

Cyclists at under 12 mph? No data. They are easy to pass when there is no oncoming traffic, so as the overall traffic volume increases, get harder to pass. Having bus lanes and functional (i.e. not blocked by parked cars) bike lanes, lanes considered safe enough by cyclists that they use them would eliminate that problem. And, if parking spaces taken away for them, reduce justification for driving in.

Oncoming traffic? This is a problem in much of the inner city: there isn't space to get through down a road in the presence of oncoming vehicles. As well as traffic volumes, we have to consider whether the rise of the Urban SUV amplifies the problem. Not only does that oncoming Volvo XC 90 on the school run take up more space, the VW Touran parked alongside the Audi Q6 means that there is less open road to play with anyhow.

Roadworks? We know about those, especially: in the centre, on the M32, along the A4174, the A370 and by Cumberland Basin. Hopefully they will be transient, as in "fixed before 2020"



One thing is for inevitable: the cost of delays caused by these roadworks won't have been included in their already broken cost model.

When that Metrobus work is finished, will the problems go away? Not without some fundamental change in how people get into the city —which means that you need a compelling story from places like Yate, from Portishead, and the other dormitory towns. A railway from Portishead here is potentially compelling, because you get a direct line to Templemeads without traffic delays.  It's a shame that central government beliefs (trains bad, BRT viable) and local government issues (naive optimism) have caused a focus on FirstBus as a solution.

Will Metrobus be compelling for those actually in its catchment area? We have no idea whatsoever. Which gives us something in common with the metrobus team.

Anyway, to close: for anyone saying "it's the 20 mph zones", or "its the traffic lights", we say "explain how the M4 moves at 12 mph on a weekday morning?"

Thursday, 29 September 2016

Traffic Jams are caused by texting drivers

With the proposal to expand penalties for drivers using phones, there have been lots of claims that the number of people texting has increased. That's something always worth validating with real datasets.

Back in September 2013, we observed that one driver in three on Arley Hill was texting.

Fast forward to 2016 and what do we see?

On a single pedal-up-the-contraflow, we didn't see more than 30% texting, we'd actually consider it to be less. L008HUJ/LD08HUJ (not found in DVLA DB), CN02JKO, VN11OYA (taxi?), BG62YGA, BD65WXL, CE53GMG. Six cars out of thirty one; approximately 1 in 5. Less than before.

What you can see though is that some drivers are so engrossed in their texting that gaps are building up in the queue.



That's the BMW BD65WXL and the Zafira BG62YGA

The Zafira's MOT expired on 7th Sept: that vehicle is not legal. And look at the gap the driver has let develop.

You have to be utterly oblivious to your environment to not notice that there as was a gap of 5+ vehicle lengths in front of you. Five vehicle lengths! You don't normally get that in the city, or the motorways nearby, at least not during daylight hours. Yet she's happily looking down, oblivious to the world. And she wasn't happy when this was pointed out to her. Now, it may seem irrelevant, these drivers are all in the same queue. But anyone wanting to turn up Nugent Hill (as opposed to illegally contraflow down), is having that opportunity denied to them, so creating needless congestion. Equally seriously, once the queue gets all the way to the roundabout on Cotham Brow, it has the risk of getting someone stuck in the roundabout, so blocking cross traffic. And all because they're curious what their friends are up to on Facebook.

There we have it. If people say "why has congestion got worse?", we will respond "our data implies that while the number of people texting hasn't increased, the time those drivers spend on their phone has —so making congestion worse".

Finally, at 1:11, the driver of CA09AKF is reading a kids picture book. Now, there did appear to be a child on the back, so this could be the way of keeping a bored child happy. Except: how do you read a picture book out loud? Do you turn it over going "tree!" "fish!", or what? Because the whole point of kids picture books is that you give them to the child to stare at the pictures while you do important things like check facebook for updates. If find yourself wanting to grab the picture book from the child in the back seat and read it yourself, well, life is bleak. Make sure your phone is charged up next time.

Sunday, 18 September 2016

Always good to to say hello

when driving, you only really have one emotion you can share: anger, through one button for the horn and the flicker for the lights. In contrast, on a bicycle, you can have spontaneous conversations with passing cyclists —even strangers.



Here we see our instrumented tax dodger striking up a conversation with a fellow cyclist. To make it more personal, rather than shouting out anything from a distance, say "I am coming through why don' t you look before you pull out", instead they wait until they are alongside the other cyclists before starting a bit of banter with a "hello!"

Unfortunately, the other cyclist doesn't appear in the mood for idle chatter, and appears distinctly unhappy to have been surprised by the greeting. Of course, if he had actually looked before pootling out onto the roundabout, he wouldn't have been surprised —indeed, our camera-enhanced tax dodger may have missed the opportunity to make a new friend