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

Monday, 12 September 2016

Clifton Occupied by Tax Dodging Cyclists!

We were shocked and disappointed that we were unable to drive to Clifton in our Important Car, then cross over to Somerset and enjoy a round of golf with Liam Fox MP. Why? Tax dodging cyclists in the road —out road, blocked off to us,Important Tax Paying people, handing it over to olympic medal winners and the like.



Lycra louts who do things like blow their noses in public


If there was one redeeming feature, it is that a lot of other people were as upset as we were to see this lycra-clad vermin —and they were standing there screaming at them for bringing the city to its knees.


We we trapped in the city. Clifton was even begrimed with a large screen showing off that the portway and Bridge Valley Road had again been stolen.



This is exactly the kind of thing people voted against George Ferguson wanted to stop, but still the city wants to let people cycle around.

It's fundamentally wrong. Look at this scene from The Promenade

Where are the revenue-bringing shoppers? Or the high-income tax band residents? Nowhere. Just one person on a bicycle who probably lives in a postcode other than BS8.

This is unacceptable!

If there is one redeeming feature, it is that Clifton Village is still not set up for more than six bicycles at any time, as their three sheffield racks were overloaded. Some of the tax dodgers even went as far as leaning their bikes against the wall of The Mall pub and trying to buy beer inside.



This is not some run-down bicycle friendly part of town where you can lean bicycles against walls; it is trying to stay upmarket. Fortunately, most of the cyclists in the area realised they were unwelcome and cycled off to other parts of the city once the event was over, leaving us nearly the only people walking round an near-empty village. The fact that village was so empty shows precisely why such cycling events must be prevented.

But how to do this? We were going to spin up our automated cyclist-hating letter generator and have it email the Bristol Post. But what did we see on the Downs?



Yes —shocking, isn't it! Our paper, the one that hates cyclists, actively trying to sell copies to cyclists!

We fear that the Evening Post has, purely in the mercenary need to sell to people under the age of sixty, has decided to start trying to ingratiating themselves with tax dodgers. They may think that will help them, but all it will do is alienate their current readership. It'll be like when all the pubs in Hotwells, including the Spring Gardens, the Pump House and the Mardyke suddenly decided they wanted to post gastropubs instead of places to get drunk in and start fights with strangers. This isn't progress: this is a sign of the decline of the city.


Monday, 5 September 2016

Gateway to Clifton: The Christchurch Mini-roundabout

Today we celebrate the Bristol School run week, now combined with the FirstBus failure week, with very unexciting documentary of the "not quite a roundabout" junction at the end of Suspension Bridge Road. If you are expecting to see anyone nearly being run over, people on phones, etc. Look elsewhere. Sorry. This video is here just to look at what transport issues Clifton has which the Clifton BID and resident groups never seem to cover.

Clifton likes to be known for its village, its Bridge and one or two of its pubs. The real Gateway to Clifton is something never discussed: a mini roundabout at the top of the village, just by the church.

To get an overview without going to Clifton, look at it in streetview and rehearse approaching the roundabout doing a right turn in a car from every road. Work out: when you should give way, when are you technically "in the roundabout and so should expect others to give way", and "is it actually possible to do all the turns legally". The answers being "no idea", "don't expect anyone to give way" and "no".

If you are cycling over the bridge, or driving near it, you have to negotiate it. It's disconcerting on a bike, especially with a child, as you cannot predict what anyone can do. It's a collection of random actions, vehicles coming in at speed, nobody knowing who to give way to —or even what side of the roundlet(*) to drive on. It's not great on a car either. There may actually be some protocol for the locals, but if so they it isn't widely known. We don't know it, certainly. What the locals and regulars do know is not to expect anyone to treat it as a roundabout —and never assume that you have the right of way.

You can see all of this in this unedited 9 minute view of the junction. Keep an eye out for the black Range Rover coming out from the left, and count how many times it does it.



This junction is fundamentally the wrong shape for a roundabout, it has two left turns, one hard, one soft, with the hard one's give way markings about 90 degrees to the roundabout itself. No visibility for anything coming off Suspension Bridge as to what vehicles coming from their right are doing —vehicles which don't often slow down, and hence won't see any cars coming from the left until they pull out. Two manoeuvres can only be executed by driving completely on the wrong side of the mini roundabout. There's one car coming the wrong up the one way street, though it does execute the junction safely. Lots of vehicles going through without pausing, including one of the cyclists coming off Clifton Down. And a couple of times cars on the roundabout have to give way to vehicles pulling on in front of them. Note the lack of tension though —regulars are forgiving of what
happens in a junction of such ambiguity.

Meanwhile that Range Rover coming off the left hand side does it five times in a row: our reporter got bored and went off while they were still doing it.

Before the video recording started the RR driver had stopped in the middle of a zebra crossing to let someone out —presumably they were now waiting for that person to return. But why were they driving round in circles given that with the RPZ roll out there's enough free parking, parking they'd have driven by? Unless they enjoy driving in circles and don't pay for diesel, the only other possibility is they had/planned to use up the 30 minute free park elsewhere. But why not just pull over with your hazard lights on? This is just a sign that some Clifton residents really are different from the rest of the city. The rest of us have mobile phones to co-ordinate dropoff and pickup operations, and to offer something more interesting to do while waiting than making right turns at this mini roundabout.

Finally: consider what it is like to try and cross this junction on foot. While it's not near the centre of the village, at the end of Manila Road (where the BMW drives out from the wrong direction of a one-way street), there's a primary school, some other ones nearby. And at the end of Suspension Bridge road is of course, the Bristol Suspension Bridge —one of the key tourist attractions in a city after Stokes Croft and the M4/M5 motorway interchange. As part of "beautiful suburb of Bristol, tucked away from the hubbub of city life and located just a five-minute drive away from the centre." we'd expect more. Maybe the shops sell postcards of it or something.

(*), Yes, Roundlet is a real word.

Gateway to Clifton: The Christchurch Mini-roundabout

Today we celebrate the Bristol School run week, now combined with the FirstBus failure week, with very unexciting documentary of the "not quite a roundabout" junction at the end of Suspension Bridge Road. If you are expecting to see anyone nearly being run over, people on phones, etc. Look elsewhere. Sorry. This video is here just to look at what transport issues Clifton has which the Clifton BID and resident groups never seem to cover.

Clifton likes to be known for its village, its Bridge and one or two of its pubs. The real Gateway to Clifton is something never discussed: a mini roundabout at the top of the village, just by the church.

To get an overview without going to Clifton, look at it in streetview and rehearse approaching the roundabout doing a right turn in a car from every road. Work out: when you should give way, when are you technically "in the roundabout and so should expect others to give way", and "is it actually possible to do all the turns legally". The answers being "no idea", "don't expect anyone to give way" and "no".

If you are cycling over the bridge, or driving near it, you have to negotiate it. It's disconcerting on a bike, especially with a child, as you cannot predict what anyone can do. It's a collection of random actions, vehicles coming in at speed, nobody knowing who to give way to —or even what side of the roundlet(*) to drive on. It's not great on a car either. There may actually be some protocol for the locals, but if so they it isn't widely known. We don't know it, certainly. What the locals and regulars do know is not to expect anyone to treat it as a roundabout —and never assume that you have the right of way.

You can see all of this in this unedited 9 minute view of the junction. Keep an eye out for the black Range Rover coming out from the left, and count how many times it does it.



This junction is fundamentally the wrong shape for a roundabout, it has two left turns, one hard, one soft, with the hard one's give way markings about 90 degrees to the roundabout itself. No visibility for anything coming off Suspension Bridge as to what vehicles coming from their right are doing —vehicles which don't often slow down, and hence won't see any cars coming from the left until they pull out. Two manoeuvres can only be executed by driving completely on the wrong side of the mini roundabout. There's one car coming the wrong up the one way street, though it does execute the junction safely. Lots of vehicles going through without pausing, including one of the cyclists coming off Clifton Down. And a couple of times cars on the roundabout have to give way to vehicles pulling on in front of them. Note the lack of tension though —regulars are forgiving of what
happens in a junction of such ambiguity.

Meanwhile that Range Rover coming off the left hand side does it five times in a row: our reporter got bored and went off while they were still doing it.

Before the video recording started the RR driver had stopped in the middle of a zebra crossing to let someone out —presumably they were now waiting for that person to return. But why were they driving round in circles given that with the RPZ roll out there's enough free parking, parking they'd have driven by? Unless they enjoy driving in circles and don't pay for diesel, the only other possibility is they had/planned to use up the 30 minute free park elsewhere. But why not just pull over with your hazard lights on? This is just a sign that some Clifton residents really are different from the rest of the city. The rest of us have mobile phones to co-ordinate dropoff and pickup operations, and to offer something more interesting to do while waiting than making right turns at this mini roundabout.

Finally: consider what it is like to try and cross this junction on foot. While it's not near the centre of the village, at the end of Manila Road (where the BMW drives out from the wrong direction of a one-way street), there's a primary school, some other ones nearby. And at the end of Suspension Bridge road is of course, the Bristol Suspension Bridge —one of the key tourist attractions in a city after Stokes Croft and the M4/M5 motorway interchange. As part of "beautiful suburb of Bristol, tucked away from the hubbub of city life and located just a five-minute drive away from the centre." we'd expect more. Maybe the shops sell postcards of it or something.

(*), Yes, Roundlet is a real word.

Tuesday, 14 June 2016

The M32 shutdown: a preview of the Zombie Apocalypse

Most films and TV series about some zombie or apocalypse or similar generally have some common visual motifs
  • A city partially destroyed.
  • Wild animals reclaiming the land. (example: 12 monkeys)
  • One or two survivors pushing shopping trollies. (Denzel Washington: The book of Eli)
  • Wide empty roads where the main protagonist can drive round fast.( Will Smith: I am Legend; the Walking Dead,...)
It's the latter that interests us. After the fall of civilisation, you will never be stuck behind a bus or or a Renault Clio veering from lane-to-lane as their satnav gives last minute directions. There's obvious question: why did everyone die in a way which left a fast route through the ruined city? For that to happen, everyone in the last 30s of their life would have to get off the M32, pull to the side of Stapleton Road, then die. In doing so, they leave a nice through route for drivers, albeit for those few survivors trying to push a shopping trolley down the pavement.

But an empty M32? It's almost worth starting a zombie plague just for that experience they promised us: centre of town to M4 in under seven minutes.

Last weekend the M32 was shut down to put in a bridge —that is, local government funding for P+R commuters from the wealthy suburbs of S Gloucs, for students at UWE (more diverse than Bristol Uni), and the affluent staff of the North Fringe —the latter with a bias towards men in the engineering/tech career path.

A whole section of the city —less affluent, more diverse and more interesting than Clifton— breathed a sigh of relief and a lungful of air that didn't taste of second hand turbo diesel. A weekend off. Something they haven't known for decades.

For us, we got to experience something similar: being the only car on the M32.

Driving down the M32 late Sunday evening, there are signs warning of the M32 closed at the Stapleton/Muller Road junction, or, to the affluent of the city, "the IKEA roundabout", that being the sole reason they'd ever get off here.



As we prepare come off, bringing up the phone to tell us how to get to Clifton without having to make eye contact with anyone, we see the flyover "40 mph limit due to faulty barriers" section. Some of the cars come off before it, a few stay on.



The first sign of an unusual situation is that the outbound lanes are empty: there is not a single vehicle leaving the city.

The sole car in front pulls off at St Pauls, leaving an empty road ahead.



This is then: the first time that we have ever seen the M32 without traffic. Those vehicles opposite? Parked. When the Zombie Apocalypse comes, people will be required to pull over to the hard shoulder and put their hazard lights on —either as their last step of being human, or their first step as a zombie, before running up the exit and trying to eat anyone sitting in Mina Road park.

For all those people who missed it: going down an empty M32 is not so much a discovery of what those builders of "the M32 parkway" imagined the experience to be, it's actually very unnerving.

All motorways in the country are full of traffic, weekends as well as weekdays. That traffic actually provides cues. If the brake lights come on in the distance, something is up, time to start coasting down. If everything is going along at different speeds in each lane; all is probably well. And if all lanes drop to about the same speed, it's busy. Pick the lane with the best stopping distance in front and be calm.

Most importantly, the other vehicles provide speed information. Because if there is one place where you do need to keep checking your speed on the dial, it's not the 20 mph zone. It's the motorways. Once you are going at 75, the vehicle noise going up to 85 is generally the same, and from there, 85-90, 90-95, easy to pick up if you get into the fast lane to pass things, then, while speeded up, start going along with the other vehicles in there. Motorways are where you do need to keep an eye on your speed. Which is what the other cars help do.

Ignoring rain/fog/snow, when you should be making decisions based on stopping distance alone, you can generally benchmark your speed relative to other vehicles. If there are trucks going past you: either you own an original British Leyland Mini 850cc —or you should speed up. In the middle lane, going along with the Astras, the Golfs and the Zafiras: you are in the 70-80 zone, where generally most people sit. If you are in the outside lane going past those vehicles, maybe you should think about pulling in once you get past them. And if you are in the outside lane and there isn't an Audi Q7 driving so close to the back that you can see the nasal hair of the driver, you are going at less than 90 mph.

In the absence of those vehicles, you have no idea what speed you are going. Instead you are too busy looking round, going "ooh, there isn't anyone in front; where is the car right behind me, the one in the slow lane about to swing past the HGV? And why isn't there someone sitting in my driver-side blind spot?". It's fundamentally unnatural —like nothing you have ever trained for. We ended up spinning up the motor to 40 mph and trying to cherish this odd event for as long as we can.

Like Halley's Comet: We shall never see it again in our lifetime.

Monday, 13 June 2016

FirstBus: don't make it a class thing: the M32 commuters would never forgive you


A PR group funded by FirstBus and other bus companies have just published a "Dodgy Dossier" on why their buses suck.

The Bristol "dead" post went for it, but chose to blame 20 MPH and RPZ zones, that is "max speed between queues" and "limit on number of vehicles that can park for free in the inner city".


In doing so they made a couple of mistakes

One: In their claim "bristol is the slowest" they forgot to say "except Reading, which the graph clearly shows is slower"


This is one of those things that the less mathematically inclined (i.e. the Brexit leadership) get wrong all the time. Smaller numbers mean "less", bigger numbers mean "more". According to the shiny graphs this PR agency made up, it takes longer to get round Reading. What's worse: you're in Reading.

Two: They missed the key scapegoats of the bus companies: the cyclists.




This issue has been picked up, along with the brazen attempt by a media relations group to appear vaguely independent.


As for the congestion, well, looking at this video from RedVee of the Centre, you can't blame the cycling infrastructure —none— for the multiple lanes of stationary traffic
.

What's causing this? The combination of (a) too many people trying to drive and (b) The Centre being ripped up for Metrobus. Does the bus marketing document note that? complain that "bus passengers are being held up by the millions being spent in the city for bus passengers?". No: they pick on the noisy ones who make lots of noise but don't get dedicated lanes down the M32.

And how do they do that: by calling out the cylists in London of being "wealthy" white men
What is less well-known, is how relatively affluent cyclists in London are compared with bus passengers. Transport for London describes the London cyclist as typically white, under 40, male with medium to high household income. [Further] A report by the London School of Hygiene and Tropical Medicine’s Transport & Health Group (LSHTM) in 2011 describes cycling in London as disproportionately an activity of white, affluent men. Only 1.5% of those living in households earning under £15,000 cycled compared with 2.2% of those living in households earning over £35,000’.

This is something the cyclist campaigners have torn into for being bogus —but we aren't here to argue that. What we are concerned about is that they are using "benefits wealthy white men" as an argument against a transport option.

For if we were to make a list of transport-related work going on in the city which would appear to disproportionally benefit the wealthy it comes down to: anything which makes it easier to get between the more well off parts of the region and their places of working, shopping and leisure.

Specifically
  1. Metrobus to Bristol International Airport connections
  2. Metrobus as a P&R alternative for most residents of North Somerset and S Gloucs.
  3. The Managed Motorway work on the M4/M5
  4. Bristol mainline train electrification

And. let's be honest: the entire M32. The people living down alongside the Frome River weren't wishing they had a flyover at bedroom window height: they believed the same bollocks that politicians always say "yes you will suffer, but it will be better in the long term", and so a motorway went in to aid the people from Clifton to head to London; to help the people who moved out of the city to live in the rural wastelands past the ring road and their ghettos of boredom around Emerson's Green. And the inner ring road work started, thankfully never completed: But notice which parts of the city came out worse. Not the bits with money.

We say to FirstBus —who also own FGW railway line—: don't make your war on cyclists a class one. Because that will call into question a lot of the infrastructure you are having built for you by local and national governments.