The 85th percentile as a tool for improving roads and streets

The “85th percentile” speed is a speed at which 85% of traffic will be travelling at, or below, along a street or road (under free flow conditions). It’s typically associated with the setting of speed limits, and (more controversially) often used as an argument against lowering them, or enforcing limits.

In particular, some police forces have been reluctant to enforce 20mph limits that have been introduced on roads that previously had a higher speed limit, without any changes to the design of the road, on the basis that enforcing this lower speed limit will prove to be too much of a drain on their resources – too high a proportion of drivers will be exceeding the new (lower) limit.

I have to admit I have changed my position on this issue over the last few years. Previously, I had been of the opinion that a speed limit is a speed limit, and that it should be enforced, regardless of how many people are breaking it. That any refusal to do so was effectively a ‘cop out’ (excuse the pun) on the part of the police.

But I think the police (or ACPO) are exactly right when they say

Successful 20 mph zones and 20 mph speed limits are generally self‐enforcing, i.e. the existing conditions of the road together with measures such as traffic calming or signing, publicity and information as part of the scheme, lead to a mean traffic speed compliant with the speed limit.

To achieve compliance there should be no expectation on the police to provide additional enforcement beyond their routine activity, unless this has been explicitly agreed.

In other words, the 85th percentile speed (the speed at which 85% of drivers are travelling at, along a road) should correspond much more closely with the posted speed limit through the kinds of measures the police list here – in particular, the design of the road. Research carried out for Manual for Streets shows that the speed at which drivers travel along a road is influenced by its design – principally its width, and forward visibility. If plenty of people are breaking a limit, that probably tells you either the limit is wrong, or the design of the street is wrong. Something has to give.

And this is the reason I am suggesting that the ’85th percentile’ could actually be a force for good – it cuts both ways. While it can be used to reinforce the status quo, it can also tell us that the design of a road is inappropriate for the posted speed limit.

Take, for instance, a situation in which a residential street with a 30mph limit has that limit lowered to a 20mph limit, without any changes to the design of the street, or to the motor traffic network. Let’s then say that the 85th percentile speed of motor traffic on this street, after the introduction of the lower limit, is much more than 20mph – close to 30mph, for instance.

What does this tell us? It tells us that the design of the street isn’t doing its job. While it might be a good idea in the short term to get the police out with speed cameras, a long-term solution should be to change the nature, character (and usage) of the road so that the 85th percentile speed on it is much closer to 20mph.

So the 85th percentile is an effective way of demonstrating when speed limits and road design are out of kilter. Take, for instance, this 20mph limit on Midland Road in London, running between St Pancras and the British Library – just one of many main roads in London that have, in recent years, had their limits lowered from 30 to 20mph without any change to the design of the road.

Screen Shot 2015-08-20 at 13.35.03

I don’t know what the (free flow) 85th percentile speed of motor traffic is here, but I’d be willing to bet good money it is way, way over 20 mph – this is a wide road, with three lanes of motor traffic bearing down on Euston Road, in one direction.

Again, we could get the police out here with speed cameras, but really, the discrepancy between the posted limit and the way people are actually behaving on the road tells us that something more serious is wrong here – the messages the road is sending out to drivers don’t correspond to the limit that has been painted on it. Something has to give.

By contrast, in this early-1990s 20mph zone in Horsham – designed to be self-enforcing – it’s pretty much impossible to drive at 20mph (despite it being one-way!).

Screen Shot 2015-08-21 at 10.01.18

A combination of speed humps, tight corners, limited forward visibility and surfacing means that the 85th percentile speed is likely to be at (or even below) 20mph, which tells us that the speed limit and the design of the road are in agreement, and there’s little or no need for enforcement.

The same logic can be applied to 30mph roads too. This road in Wageningen, NL, has a 50km/h speed limit – and it’s reasonable to assume that the 85th percentile speed will be at or below that speed, due to the design of the road.

Screen Shot 2015-08-21 at 10.04.40

The carriageway is very narrow, with motor vehicles barely passing each other, and has no centre line.

And there are other ways of bringing the 85th percentile speed into line with a 50km/h (or 30mph) limit on these kinds of distributor roads – for instance, pinch points for motor traffic (that don’t affect cycling).

Screen Shot 2015-08-21 at 10.08.57

So if the 85th percentile speed on a 30mph road near you is (under free flow conditions) closer to 40mph, that should tell us that action is needed to bring driver behaviour more closely into line with the posted limit, through these kinds of measures. Principally, perhaps, by reclaiming a good deal of the carriageway for cycling, consequently narrowing it down for motor traffic.

I hope this explains why I’ve changed my mind, and why the 85th percentile can be a constructive tool for improving streets for walking and cycling!

Posted in Uncategorized | 30 Comments

Entrenching car dependence with brand new development

A few months ago I commented on the new Waitrose/John Lewis retail site in Horsham, principally in relation to the way the visualisations of the (then yet to be opened) new development ducked the problematic issue of a very busy road severing the site from the town centre, but also on the potential difficulties of getting to the site by bike and on foot.

Now that the site is open, it is quite obvious that, yes, walking and cycling have been completely failed by the planning process. As I hope to explain here, cycling to Waitrose and John Lewis is effectively impossible, except for those who want to cycle (illegally) on footways, or for the tiny minority of people who are prepared to ‘negotiate’ with motor traffic on a dual carriageway carrying 20-25,000 vehicles per day.

To set the scene, here’s a video I’ve made showing the ‘legal’ cycling route to Waitrose.

To repeat some of the points made in the video – this isn’t an ‘out of town’ site, it is just outside the town centre, separated from it by the road I am cycling on. The route shown in the video is the one that will have to be taken by the vast majority of people who live in Horsham if they want to legally cycle to Waitrose – only a small proportion of the town’s population live in the ‘opposing’ direction, and they too will have to cycle on this dual carriageway, as this is the only access for the supermarket.

There is heavy traffic in the video which actually makes the experience of cycling to the store slightly less hostile, principally because of reduced vehicle speeds. At less busy times, moving out into the outside lane (as I do in the video) is much less easy because motor traffic will be travelling at or above 30mph.

The video also shows someone cycling on the footway, from the supermarket. This isn’t legal (and I don’t think it should be – the footways, as currently designed, are too narrow). But it is exceptionally common. People want to cycle to Waitrose, but faced with the choice between a four lane, high speed, high traffic road, and trundling on the pavement, people are unsurprisingly opting for the latter.

Not setting out to to break the law - just being failed by highway engineering

Not setting out to to break the law – just being failed by highway engineering

Cycling has been squeezed out on these kinds of roads for decades, and this new development has done nothing to address this root problem. The only silver lining on the cloud here is that, in undoubtedly attracting more ‘ordinary’ people on bikes to find their way along this road to the supermarket, the problem is now increasingly visible and less easy to ignore.

My video also shows the stupidity of planning entirely around motor traffic – from start to end of the video, my trip is only around 300m as the crow flies, but it takes me three minutes to cover this distance, in large part because to even get to the front door by bike (which is where people cycling should be going) I have to go out of my way to a roundabout, and then negotiate my way through two levels of a car park. There is no direct access to the front door by bike.

Screen Shot 2015-07-21 at 11.57.45

Some amazing open goals have also been missed here – whether by Waitrose themselves, or by council officers, or both.  Mainly, there are no access points into the site from the surrounding area, only the road I cycle on in the video. This is incredibly frustrating.

Standing in front of the main entrance, it is quite easy to see the main road to the north. The silver car is travelling along this road, and the white building is on the far side. It is a distance of only 80 metres or so from where I am standing.

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But there is no walking (or cycling access from here – instead, you have to go take the long way round, the motor traffic route. I’ve marked this obvious (missing) connection on the visualisation of the site – the red line.

Screen Shot 2015-08-17 at 11.39.45

This is looking north, across the site, to the road running east-west (left-right). But there is no connection through to the west, either – a housing estate clearly visible, and a passage there to the side of the supermarket, but… fenced off.

Screen Shot 2015-08-17 at 15.53.41

This missing connection would run here – again, marked in red.


Again, the absence of this connection means a walk of a few metres is converted into one of several hundred.

Nor is there access at the south-west of the site. The development looms behind the housing here (circled) but again, no direct access, no connection with an existing path running along the river.

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The overall impression is of a development that has been plonked down, with no thought or consideration, no attempt to connect it up sympathetically with the surrounding area, by foot or by bike.

The three missing connections described here, in red - with the only existing access (from the major road) marked in blue

The three missing connections described here, in red – with the only existing access (from the major road) marked in blue

Anyone living to the south, west, or north of this site has to go some distance out of their way to get to it. Combined with the hostility of the road you are forced to walk along, or cycle on, this development has entrenched, indeed worsened, car dependence within the town, which is pretty appalling given that this was a blank slate, in 2014.

The final insult - useless bike parking, which is (of course) placed as far away from the entrance as possible

The final insult – useless bike parking, which is (of course) placed as far away from the entrance as possible

Posted in Car dependence, Horsham, Horsham District Council, Infrastructure, Town planning, West Sussex County Council | 35 Comments

Talking about ‘danger’, again

Some thoughts about ‘danger’ and ‘dangerising’ cycling had been floating around in my head, following recent local discussion about whether talking about ‘danger’ puts people off cycling, and whether we should refrain from talking about it all.

This issue has reappeared today, with some comments from Anna Glowinski in the Evening Standard (that may or may not have been accurately reported).

Speaking as she prepared to race today in a pop-up street velodrome in Broadgate, Glowinski told the Standard: “I think it can be quite damaging to talk about how ‘dangerous’ cycling is. I really don’t think it is that dangerous. The reason I think women are getting hit by lorries is because it’s an assertiveness thing. […]

“I think it’s good that cycle safety is taken seriously and highlighted so it’s high on the political agenda, and people care about road safety and think about how to make certain junctions safer,” Glowinski said. “But constant highlighting of cyclist accidents can be a bit misleading. I get told all the time: ‘You are taking your life in your own hands, you are crazy.’ It’s misleading. It’s putting people off.

I’ve emphasised in bold the passages that I think exemplify the kinds of objections made by people who think we shouldn’t talk about ‘danger’. We’ve been here before, of course, and others have eloquently covered the same ground.

At face value Glowinski’s comments appear confused – on the one hand she thinks it’s good that safety is on the agenda, and that we are talking about how to make roads safer. But at the same time a ‘constant’ highlighting of these issues is a problem. Is it even possible or sensible to draw a line here? This leads me to believe she may have been selectively quoted, or was pushed for a quote on something she didn’t really consider.

But, more generally, I think an important distinction often gets missed here. It’s vital to stress that when people like me, who are interested in increasing cycling levels substantially in Britain, talk about danger – both in objective terms, and in the way perception of danger is a major barrier to cycling uptake – we are not arguing that cycling is an intrinsically dangerous mode of transport. We aren’t say that cycling itself is dangerous.

Instead, quite specifically, we are arguing that the design of certain roads and streets, and the nature of the motor traffic using them, presents an unacceptably high risk to people cycling on them. Cycling on a quiet residential street, with very low levels of motor traffic, is acceptably safe to anyone, but obviously very different from cycling around the Elephant and Castle, or Hyde Park Corner, or through Kings Cross, places where you have to make your way across multiple lanes of motor traffic travelling at higher speeds than you.

Screen Shot 2015-08-13 at 21.09.02… Or through junctions where you are mixed with a high proportion of HGVs. Or sharing space with motor traffic travelling at the national speed limit on rural A-roads, or trunk roads.

Exposure to this kind of motor traffic is unacceptable. It continues to baffle me why, in a country that (quite rightly) takes Health and Safety very seriously, these risks continue to be tolerated. Certain kinds of step ladders have to be used in the workplace, yet it is apparently fine and dandy for local authorities to build new roads where people cycling are expected to mix with heavy traffic, travelling at speeds of 50 or 60mph, ‘negotiating’ their way into the middle of the road to get around roundabouts.

A new road in West Sussex. Cycle here.

A new road in West Sussex. Cycle here.

The only way these roads even appear to be ‘safe’ is because next to no-one is using them on a bike. (Despite this, cycle KSIs on these kinds of roads form a considerable percentage of the total, even if the number of trips being made on them by bike is 1-2% of the total.)

The reasons so much of the British road network is dangerous for cycling are established reasons –

  • speed differentials while sharing the same road space;
  • major differences in mass while sharing the same road space;
  • unforgiving road design;
  • unpredictable or uncertain layouts;
  • layouts that fail to account for human fallibility.

In short, all the attributes that are being designed out of Dutch roads and streets, thanks to Sustainable Safety.

Big differences in speed, mass and momentum means separation is a necessity.

Big differences in speed, mass and momentum means separation is a necessity.

Meanwhile Britain squeezes cycling onto roads that are simply not designed to accommodate it safely – with predictably tragic outcomes.

Does pointing this out really ‘put people off’ cycling? I think that’s a pretty far-fetched assertion. For one thing, we’ve been talking about road safety in general for decades in often quite vivid detail – in particular, car safety – without putting anyone off driving. And we have succeeded in greatly reduced the exposure drivers face while travelling around on roads and streets, by designing more forgiving environments for motoring, that tolerate minor mistakes, and reduce the seriousness of consequences when mistakes occur. (The problem is that cycling has largely been ignored in this process).

The implication of the ‘putting off’ claim, therefore, is that cycling is an especially fragile mode of transport, one that can collapse when people talk about the downsides of it; that exposure to risk and danger, and the perception of it, genuinely is a problem for cycling, compared to other modes of transport.

But even for the ‘putting off’ claim to stand up to scrutiny, there must exist some large cohort of the population that is willing to cycle on roads that have all the kinds of problems described here, yet will choose not do so simply because these problems are being talked about.

Is this really at all probable? Are they somehow blind to the hostility of these roads and the hazards they present, yet simultaneously so danger-sensitive that mere words will stop them cycling on them?1

The general public might not be particularly au fait with the principles of safe road and street design for cycling, but those principles will correspond closely with what we as human beings can instinctively judge to be unsafe. Faster motor traffic whizzing past us at close proximity feels unsafe. Being surrounded by HGVs feels unsafe. Junctions which present multiple potential conflicts and uncertainty about what other parties might be doing feel unsafe. And so on. These are the reasons most people don’t want to cycle on Britain’s roads.

I think most human beings are pretty good at assessing risk for themselves; they might not get it right all the time, but they can judge that it is safe enough for their children to pedal around in a park, or on a small section of pedestrianised street that rarely carries any motor traffic…

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… while at the same time judging that allowing their children to cycle on the road with HGVs at the junction just yards away, in the background of the same photograph, presents an unacceptable level of risk.

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This is exactly the point that David Arditti makes in the post I have already linked to –

I think the advocates of cycling need to stop treating the public like idiots who cannot correctly judge what is or is not an unacceptably dangerous activity for them to engage in. I think they can judge.

The public knows that cycling itself isn’t dangerous. That’s why families will wobble around parks, and up and down trails, and in those places they feel comfortable. But they do know that cycling on certain types of road presents a kind of risk – even a feeling of risk – that they simply aren’t prepared to tolerate.

Talking about addressing those risks isn’t going to stop anyone from venturing onto those roads on a bike, who wasn’t already prepared to do so.

1. [I am vaguely aware that statistics suggest there may have been a ‘dip’ in London cycling levels following the six fatalities in quick succession in late 2013; but this is surely attributable to the deaths themselves, rather than the people making the case for changing they way roads are designed to prevent these kinds of deaths from occurring in the future.]

Posted in Uncategorized | 62 Comments

British ‘Simultaneous Green’ junctions, in… 1979?

I’m currently working my way through a DVD set of films from the BFI on cycling in Britain. One of these films is called ‘Free Wheeling’, which you can watch yourself on the BFI site (although it will cost you £1).

The film was produced for the Department for Transport in 1979, and appears to be aimed at councils and local authorities, showing them what can be currently be designed for cycling, based around Local Transport Note 1/78, Ways of Helping Cyclists in Built Up Areas, which we see, and is referred to, several times in the film.

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It’s quite eye-opening – there are some things in there that were obviously radical at the time, like contraflow cycling on one way streets (something that, ridiculously, we still struggle to implement with any consistency 36 years later!).

What really caught my eye, however, was this short section on signalised junctions.

To my (untrained) eye, at least, this looks remarkably like, well, a simultaneous green junction – two of them.

In the first section of the clip, we see a man on a bike setting off from a bicycle-specific signal, heading diagonally across a junction, while other people cycling emerge from the road he is heading towards.

Screen Shot 2015-08-12 at 00.20.47Note that there is apparently nothing to stop any of these of people choosing to cycle off into any of the exits they want to use.

And indeed this is precisely what happens – the man and the woman emerging from the junction opposite do head off in different directions, the woman ‘yielding’ to the man in the blue jumper.

Screen Shot 2015-08-12 at 00.22.19As this occurs, the voiceover states

There are many variations [of this type of junction] possible, depending on local circumstances

which funnily enough is exactly what David Hembrow has been saying about ‘simultaneous green’ arrangements for cycling – that they can work at junctions of different sizes and shapes.

The second junction in the clip is even clearer. We see two people arriving at the junction, waiting at the corner on cycle-specific infrastructure, for a green signal to progress across the junction.

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Note that this ‘corner’ arrangement is precisely the same as that at ‘simultaneous green’ junctions in the Netherlands.

Screen Shot 2015-08-12 at 00.29.07Positioning on the corner allows people entering and exiting the junction to take the most direct route across it for the destination they want.

As the two cyclists get a green signal, all motor traffic at the junction is held.

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As in the previous example, people cycling emerge from the opposite side of the junction – not directly opposite, but from a cycle track at 135° to their own entrance to the junction.

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Note, again, that there is nothing to stop people choosing whichever exit they please. All these (conflicting) options are possible.

Screen Shot 2015-08-12 at 00.33.00The final lovely detail is that there is an induction loop to detect people waiting at the junction; something commonplace in the Netherlands, but extraordinarily rare in Britain.

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I’d love to know where these two junctions are – my guess, from the rest of the video, is somewhere in Peterborough – and indeed what happened to them, Do they still exist today?


An eagle-eyed Jitensha Oni has spotted that the second junction is indeed in Peterborough, near the railway station. It looks to have been replaced with a large roundabout, albeit with some pretty decent-looking grade-separated cycling provision.

As others have pointed out, these aren’t strictly simultaneous green, as while any exit can be chosen by people cycling, there are only two (opposed) entries to the junction at the same time. Still, I imagine this was pretty radical at the time, and still is now!

Posted in Uncategorized | 10 Comments

Cycling and the Royal Parks

TfL’s response to the consultation on the route of the Superhighway through Hyde Park was released last week. It reveals, yet again, a curious hostility to cycling from the Royal Parks, the (government) agency that manages the eight Royal Parks in London.

This is the same body that is effectively blocking the most sensible routing of the Superhighway past Buckingham Palace for ‘safety, operational and aesthetic reasons’; that bans cycling along the eastern side of Green Park (yet allows driving, for access); that is apparently reluctant to close parts of Regents Park as through-routes to motor traffic; that organises regular ‘crackdowns’ on cycling, including (notoriously) one last year which saw BBC presenter Jeremy Vine stopped by the Met Police for ‘speeding’ (at 16mph).

The curiousness of the Royal Parks’ position was neatly summed up by City Cyclists back in January

it seems to me that the [Royal Parks] authority is terribly concerned that building a safe cycle route through this area might lead to conflict with pedestrians. Fair enough. But I don’t see any evidence that The Royal Parks understand that much of that potential ‘conflict’ is because they are trying to squeeze people on foot and bikes into small spaces at junctions that are absolutely mobbed by motor vehicle traffic. The elephant in the room is that there is an awful lot of motor vehicle traffic in the Parks. Why isn’t The Royal Parks worrying about removing some of that, I wonder?

And indeed this latest response from TfL to the consultation reveals that the Royal Parks are still thinking this way. For instance –

3 respondents (<1%), including The Royal Parks, expressed concern about provision for cyclists on North Carriage Drive

The Royal Parks stated that the proposals are not safe enough for pedestrians. Most of these cited potential clashes with cycles due to increased cycle congestion in certain areas of the park

The Royal Parks stated that impact on pedestrians needs to measured and a risk assessment undertaken

Nobody wants to see more conflict between walking and cycling, but it seems to me that the Royal Parks are coming at this issue from a perspective that is bound to see problems where they don’t exist, and fails to diagnose solutions where they can be found.

First of all, from the tone of their comments on this consultation, and other public responses, they appear to have a fairly fixed idea of ‘cycling’ being the preserve of fast, speedy types, posing grave danger to other users, rather than as a potentially universal mode of transport that could be used by all visitors to the Parks. Indeed, these people exist in the Parks already, and they are hardly a great danger to other users.

Ordinary people, using bikes, in Hyde Park

Ordinary people, using bikes, in Hyde Park

Ordinary people need safe routes through (and obviously to) the Parks by bike, not just ‘cyclists’, and those routes shouldn’t be compromised because of assumptions about speeding, or bad behaviour, or lycra, or whatever. If there is a genuine issue with bad behaviour, that should be tackled directly, rather than punishing everyone else by not even providing proper routes in the first place.

Secondly, all the (potential) problems with conflict between different users in the parks are almost certainly design problems, rather than any intrinsic problem with cycling itself. Where there are currently issues with ‘speeding’ in Hyde Park, for instance, it’s notable that it is on a desperately narrow shared path, along Rotten Row.

The Rotten Row shared path

The Rotten Row shared path

With two-way cycling on the right hand side of that white line, it’s hardly surprising that conflict with walking on the other side of the line is going to occur, with ‘fast’ cyclists seeming to come out of nowhere.

Parks across Europe handle much larger numbers of people cycling, with much less conflict, because their paths are designed to safely accommodate it. In Utrecht –
Screen Shot 2015-08-08 at 23.51.18
In Lyon –
Screen Shot 2015-08-08 at 23.49.03And of course in Amsterdam.Screen Shot 2015-08-08 at 23.49.42There isn’t conflict in these parks, precisely because there is enough space allocated to walking and cycling for everyone to get along quite happily. The problems that result from pushing people together into a tiny space isn’t a problem with cycling; it’s a problem with bad design.

This fixation on the ‘problems’ cycling might cause is even more curious in the light of the Royal Parks’ ambivalence about motor traffic levels in the areas it controls – the Royal Parks maintains at its own expense roads that carry motor traffic through Hyde Park, for instance. We are told that

It is The Royal Parks’ aspiration to reduce the number of motor vehicles in the Royal Parks. It does not feel an immediate ban on cars in Hyde Park is considered feasible given the impact that this would have on those who currently visit by car and taxi.

Reductions in motor traffic would obviously be welcome, but it’s not clear how this is going to be achieved without restrictions on the routes motor traffic can take through the parks. A ‘ban’ on motor traffic needn’t even be a priority in the short term; the main problem with motor traffic in the Parks is how the roads in them are used as through routes. These roads could be converted to access roads, still allowing people to visit by car, but removing the motor traffic using the Parks as a cut-through to somewhere else.

The Royal Parks seem innately conservative; wedded to preserving the status quo, even if that is deeply sub-optimal in terms of safety and convenience, especially for people walking and cycling.

Posted in Uncategorized | 19 Comments

Blindness to motor traffic

An essential component of whether a road or a street is a pleasant place is the amount of motor traffic travelling down it. It isn’t the only component, of course, but it’s going to be a struggle to make somewhere that has tens of thousands of motor vehicles travelling through it into an attractive destination. Conversely, streets that have very low levels of motor traffic – or indeed no motor traffic at all – are very much easier to ‘convert’ into destinations, places where people would like to hang around, rather than rushing off somewhere else.

This will often have very little to do with the way the street itself is designed. Waltham Forest managed to transform Orford Road into a pleasant place, simply by closing it to motor traffic.

Orford Road trial closure

People were happy to mingle in the street, and to let their children play in it, despite the ‘conventional’ road layout remaining, with tarmac, kerbs, and street markings.

The same is true of Earlham Street in Camden; again, a ‘conventional’ street became a place people were happy to wander around in, simply by the addition of a closure to motor traffic – without any changes to the street layout.

Screen Shot 2015-08-04 at 17.10.48And even major roads in central London became places pedestrians were happy to wander around on, at will, when they were brought to a standstill by a taxi demonstration last summer.

The Strand, and Trafalgar Square, accidentally become places.

The Strand, and Trafalgar Square, accidentally become places.

This is surely all fairly obvious stuff; yet there is a curious blindspot on the inescapable influence of motor traffic levels on the quality and attractiveness of our street environments, particularly (and most troublingly) amongst many of the people who have responsibility for what happens to them, or who are engaged in the design and function of them.

It is a little unfair to single any particular individuals out, especially people who are thoughtful and reflective on how streets work, and how how they could be improved. But an analysis of Exhibition Road by John Massengale and Victor Dover in their book, Street Design: The Secret to Great Cities and Towns is such a good example of this phenomenon it’s hard not to point to it.

In a two-page section on this ‘shared space’ design – perhaps one of the most famous examples of this kind of design in Britain – the authors reflect on why this street is both a success and a failure, and arrive at some reasonable conclusions. The treatment on Exhibition Road is described as a ‘mixed success’, the authors finding that the very southern half of the street, south of Thurloe Place, is a success, while the section north of it (and north of the A4 Cromwell Road) is something of a failure. Here is the relevant passage, quoted in full –

The innovations at the southern end of Exhibition Road have been more successful than the primary stretch between the museums and other institutions. Thurloe Street and the adjacent plaza are small-scale, comfortable spaces that are well used by the public. Both are lined with attractive storefronts that have been revived by the popularity of the new design, now filled with several cafés with outdoor dining, a bookstore for the Victoria and Albert Museum, and other shops. Cars can enter the Exhibition Road space here, but it feels more like a piazza than shared space. Low ventilating stacks for the tube station and a tunnel leading to it poke up in the middle of the space, helping the spatial definition. Built-in benches attached to the stacks are frequently occupied by those who don’t have to spend money to spend time people-watching, and the few cars and vans that park in the square tend to cluster around them, giving some visual order to the parking. On the street itself, bold striping in light and dark grays clearly sets the space off from the through traffic on Thurloe Place.

The effect of these paving techniques on the long, wide piece of Exhibition Road to the north is less pleasing, because here the street feels vast and poorly shaped. The bold diagonal striping is visible for many blocks, and since there are no sidewalks, the supergraphic bumps into the institutions lining the road in an almost random and uncomfortable way. On the small piazza to the south, on the other hand, the paving pattern seems less repetitive and is broken up by the ventilation shafts and the benches around them, the parked vehicles, and the number of people in the space. The outdoor tables on the southern block of Exhibition Road also cover the supergraphics at the edges, softening their effect.

A smaller pattern north of Cromwell Road would bring a more human scale to the vast space, and breaking it into smaller parts would help, too. A more traditional design would make borders along the edge and break the long space into smaller parts. cars park in the center of the road, which has traffic on one side and pedestrians on the other. “Only the parked cars look comfortable,” says Hank Dittmar, the Chief Executive of the Prince’s Foundation.

This is all clever, intelligent analysis, but amazingly (to my eyes, at least) there is absolutely no mention here of the difference in the levels of motor traffic on the distinct sections of the street that are considered to be a success, and to be a failure. The section that they feel is a success has a relatively tiny amount of motor traffic, only accessing the shops and premises on the street itself, and the handful of properties on Thurloe Street, while the section they deem to be a failure has a considerable amount of motor traffic – around 15,000 vehicles a day.

Yet this difference is not mentioned, at all.

Instead, the authors attribute the differences in quality to what are, in reality, very minor design details. Indeed, the differences in design have to be minor, because the layout of the street is essentially identical in the two sections that are deemed to be a failure, and a success.


The south section – a supergraphic extends from building to building, across the whole width of the street.

That same supergraphic, extending from building to building, across the same width of street.

North of the Cromwell Road – the same supergraphic, extending from building to building, across the same width of street.

This continuity of design is even more obvious in aerial shots of the whole length of the road.

Picture from here.

Picture from here.

The main reason for the difference in quality is obvious – the north section is a busy road and car park, while the south section isn’t, carrying only a negligible amount of traffic on what is actually a minor access road. 

The southern section of Exhibition Road is not a useful route for motor traffic. So it is only used for access purposes.

The southern section of Exhibition Road is not a useful route for motor traffic; anyone accessing it will be sent back where they came from. So it is only used for access purposes.

So while the authors observe that ‘the rebuilt road changes character as it goes north’, they fail to remark upon the principal reason why this is so – very different levels of motor traffic.

The reason the southern section – which has the same street layout as the northern section – feels like ‘a piazza’, and ‘a small-scale, comfortable space’, and where people will actually want to sit out on the street and eat a meal, or watch people walking by, is because it is not full of motor traffic. Nothing more, nothing less.

Is this failure to recognise the importance of motor traffic levels important? I think it is. I think it explains why towns and cities have been so ready to embrace ‘shared space’ as an apparent solution to the problems with their roads and streets. Current levels of motor traffic on a given route are taken almost as innate, an essential characteristic that cannot be changed. It’s background; the ‘problem’ to be solved then becomes one of how to arrange that motor traffic on the street, how to manage its interactions, how to make it ‘behave’, rather than one of determining the function and purpose of a road or street, and determining the level of motor traffic it should be carrying accordingly.

Dutch access roads work well because they are designed to eliminate through traffic, often in very subtle ways – an arrangement of one-ways, for instance, or simply a fast, obvious parallel road. The success of these layouts actually has very little to do with the design of the streets themselves.

The children are able to play safely in this residential street in Gouda not because of any 'shared space' or similar treatment, but because this is not a through-route for motor traffic.

The children are able to play safely in this residential street in Gouda not because of any ‘shared space’ or similar treatment, but because this is not a through-route for motor traffic.

Streets like the one in the picture above are designed the way they are because motor traffic has largely been removed from them; they are not designed that way in an attempt to mitigate the effects of motor traffic. They are able to function as ‘shared’ because of low motor traffic levels; their design is essentially a bit of icing on the cake.

Of course at the other end of the scale, by ignoring the reality of motor traffic we risk designing inappropriate ‘sharing’ into roads that are far too busy for anyone too actually consider sharing, creating (at some expense) what amount to fairly conventional roads, but ones that have serious downsides for groups like those who are not included on the carriageway or the footway, or those with disabilities like visual impairment. Roads that will continue to function as distributor routes for motor traffic should be designed with the needs of all users in mind, even if in practise that means a dilution of the ‘placemaking’ value of any redesign.

We ignore the importance of motor traffic at our peril.

Posted in access roads, Shared Space, Sustainable Safety, The Netherlands | 16 Comments

True safety lies with design

I shared some pictures the other day, in an attempt to convey a fairly simple message – that the safety record of the Netherlands for cycling is almost entirely attributable to the physical environment people cycle in, and that it isn’t down to exemplary behaviour (either of people cycling, or of people driving), or down to clothing, or safety equipment, or special lighting, or any other kind of gimmick.

Screen Shot 2015-07-28 at 18.22.01 Screen Shot 2015-07-28 at 18.24.13

Admittedly it isn’t particularly obvious from the photographs, but these pictures were taken at two large, busy junctions in Utrecht – the first is at the Westplein, a major junction just to the west of the train station, the second is the junction of Vleutensweg and Thomas a Kempisweg. The people in the pictures are able to negotiate these junctions in total safety, despite doing what they are doing, and wearing what they are wearing, and riding battered bikes, because they are completely separated from motor traffic, either physically, or in time, with dedicated green crossing stages for cycles.

I am not necessarily condoning this behaviour – my point was that the superior Dutch safety record is achieved in spite of it.

It’s hard to generalise, but you rarely see people carrying exceptional loads, or texting, or cycling with dogs, or giving backies, in British cities, but all these things are extraordinarily common in Dutch cities, while hi-visibility clothing and helmets are almost entirely absent. Indeed, I would even estimate that people with functioning lights are definitely in the minority in the centre of larger Dutch cities.

Screen Shot 2015-07-29 at 10.02.58It is blindingly obvious, therefore, that safety – true safety – for people cycling does not lie with behaviour, or with clothing or equipment, but with a safe environment, one that allows what in British eyes might be ‘stupid’ behaviour, but that is in reality just natural, flawed, human behaviour in an environment that feels safe.

The Dutch safety record is actually even more remarkable because of the broad demography of the people cycling, particularly those that are most vulnerable – young children, and the elderly. 23% of all trips Dutch people over the age of 65 make are cycled.

Screen Shot 2015-07-29 at 17.20.32 Screen Shot 2015-07-29 at 17.22.17These are people for whom even minor incidents could be quite serious.

Likewise 40% of all trips Dutch children under the age of 17 make are cycled. This group is vulnerable in a different way. Firstly they are inexperienced, and still learning how to use the road network…

Screen Shot 2015-07-29 at 17.27.54

… and secondly, kids (and especially teenagers) will prat about. It’s just what they do.

Screen Shot 2015-07-29 at 17.28.11Again, the Dutch environment is forgiving enough to accommodate this behaviour while maintaining safety.

Nor does safety in the Netherlands lie with exemplary (or even slightly better) driver behaviour. You will see the same kind of impatience, driver error, speeding, tailgating, and silly behaviour as on British roads. Stand at a busy junction for motor traffic, and you will see drivers fiddling with their phones, or speaking on them. Dutch drivers will SMIDSY too, when they encounter junctions where they have to process a lot of movements and interactions.

Assen's most dangerous junction. We only had to stand here for five minutes before we saw this incident.

Assen’s most dangerous junction. We only had to stand here for five minutes before we saw this incident.

Why would it be otherwise? The Dutch are human beings, just like the British, and are just as fallible and flawed as we are, when they are behind the wheel of a car.

Mobile phone user, Utrecht

Mobile phone user, Utrecht

Motorway tailgating at over 100kph

Motorway tailgating at over 100kph

The essential difference with Britain, however, is that, while cycling in the Netherlands, you are almost entirely insulated from this bad behaviour. On main roads you are not in the same space as drivers. Often they will be some distance away, even invisible.

Cycle path along an 80kph A-road, east of Assen. The road is on the left-hand side, behind the trees.

Cycle path along an 80kph A-road, east of Assen. The road is on the left-hand side, behind the trees.

In urban areas, particularly in new developments, routes for bikes and motor traffic will often be completely unravelled, with entirely separate ‘main roads’ for cycling and motor traffic between destinations.

Major junction to the north of Zwolle. Cycle traffic has the direct route into the new development, on the bridge. You will not go anywhere near this road.

Major junction to the north of Zwolle. Cycle traffic has the direct route into the new development, to the right, on the bridge. You will not go anywhere near this road.

And on residential and access streets, motor traffic is only there for, well, access reasons, meaning your chances of encountering drivers speeding somewhere else are negligible.

Residential access road, Zwolle

Residential access road, Zwolle

This policy also means that side roads are infrequently used by drivers, again meaning potential conflict with motor traffic is greatly reduced.

Crossing a residential side road in Utrecht. Not many motorists will be using this junction - only for access.

Crossing a residential side road in Utrecht. Not many motorists will be using this junction – only for access.

Where interaction does (infrequently) have to occur, like at the side street shown above, design helps to ensure that it is clear who has priority, and that there is little to be gained from driving badly.

It is this whole raft of design measures that means interaction with motor traffic is negligible by comparison with Britain, and usually benign when it does occur. Although idiot drivers undoubtedly exist, your chances of meeting one are greatly, greatly reduced. By contrast, in Britain, you are almost always continually exposed to that idiocy, sharing the same road space as motor traffic on main roads, and indeed on side streets which will often form through routes for drivers, trying to get somewhere else.

True safety lies with design; design that accounts for human fallibility, rather than design that relies on perfect human behaviour, or on attempts to create better human beings.

Posted in Uncategorized | 33 Comments

Getting ‘shared space’ the wrong way round

There’s been a fair bit of discussion of ‘shared space’ recently, prompted mainly by the Holmes Report into Shared Space, which was released at the start of the month.

‘Shared space’ is of course a catch-all term that covers a wide range of street and road treatments, but in essence it involves reducing distinction (either visually or physically, or both) between the carriageway and footway – between places where users are ‘expected’ to be, in general.

I don’t think there is any genuine, or ‘ultimate’, shared space out there – one that has no distinction whatsoever across the whole building-to-building width. You will always find some kind of distinction, be it in the form of tactile paving, or colour difference, or a minimal kerb upstand, or bollards, between where different modes should be going.

Exhibition Road isn't really all that 'shared' - tactile paving, a drain, and bollards all combine to create a pretty visually distinct carriageway and footway

Exhibition Road isn’t really all that ‘shared’ – tactile paving, a drain, and bollards all combine to create a pretty visually distinct carriageway and footway

Screen Shot 2015-07-12 at 16.20.42

Likewise Poynton – again, a clear kerb line, and material difference, make it obvious what is footway, and what is carriageway

New Road in Brighton perhaps comes closest, with only a drain breaking up the uniform surface – but here sheer weight of pedestrians numbers, and a tiny amount of motor traffic, make this resemble a genuinely pedestrianised street with limited motor traffic access.

Screen Shot 2015-07-12 at 16.25.30And this points toward something a little bit back-to-front about how these treatments are often applied in Britain. New Road is a bit of an exception; it is effectively an access road, one that makes little or no sense to drive down if you want to go anywhere, because a one-way system sends you back to where you’ve come from.

By contrast, ‘shared space’ treatments are instead frequently applied on roads that are through-routes for motor traffic, carrying it from somewhere, to somewhere else. Poynton is composed of a junction of major A-roads; Exhibition Road carries around 15,000 vehicles a day; Byng Place in Camden is a through-route; major schemes in Coventry and Ashford have both applied ‘shared space’ treatments to main roads. Preston, too, appears to have jumped on the bandwagon in the last year.


‘Shared space’ on Preston Fishergate, which remains a through-route for motor traffic.

Indeed, all the examples of ‘shared space’ shown in the Sea of Change film – areas where partially-sighted and blind users have difficulty crossing roads – involve through routes for motor traffic.

Meanwhile, all the small access roads near these big main road schemes – residential streets, or streets that (should) serve no through function for motor traffic – are left with ‘conventional’ highway engineering, footways with high kerbs, clearly distinct from what look like roads, rather than streets.

For instance, it is the through-route Exhibition Road that has the ‘shared space’ treatment (and a 20mph limit), while, bizarrely, the minor residential side-street joining on to it, Princess Gardens, has a conventional tarmac road appearance, and a 30mph limit.

Princess Gardens, in the background, complete with standard road engineering, and 30mph limit

Princess Gardens, in the background, complete with standard road engineering, and 30mph limit

This is, really, the wrong way round, and entirely opposite to the way the Dutch conventionally design roads and streets, and distinguish between them.

In the Netherlands, the ‘shared space’ style treatments are applied on streets that have been quite deliberately designed to remove through traffic, leaving only a very small number of motor vehicles using them – the access roads. Meanwhile the main roads, carrying through traffic, usually have very clear distinction between the carriageway and the footway (in large part because the Dutch clearly separate cycling from motor traffic on these kinds of roads).

So what looks like the kind of treatment we might see on a fashionable main road in Britain is almost always applied on a very low motor traffic access road in the Netherlands. Examples from Wageningen, Gouda, ‘s-Hertogenbosch, Veenedaal, Utrecht, and Assen below – all very low (motor) traffic streets.

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Although these treatments looks like ‘shared space’, these are all autoluwe, or very low car traffic areas.

These are appropriate locations for a lack of definition between footway and carriageway because the reason for that distinction – motor traffic – is no longer present.

By contrast, the main roads near these access roads will have clear definition, because… well, these roads are still carrying a significant quantity of motor traffic – distinction is required.

A main road in Wageningen.

A main road in Wageningen.

… And a main road in Utrecht.

… And a main road in Utrecht.

I don’t quite know how, or why, Britain appears to have grasped the wrong end of shared space stick, applying treatments designed for streets that are intrinsically suited to sharing – access roads – onto main roads instead, in an attempt to fix them.

Perhaps it is because of an innate reluctance to accept we have a motor traffic problem. Perhaps we are attempting to convince ourselves that we can turn traffic-blighted roads into ‘places’ simply by changing the way they look, rather than honestly accepting that they are through-routes, or accepting that genuine places require an access-only function for motor traffic. (I’ve written about the need for honesty – and placefaking – before).

There is a role for shared space design (or whatever you want to call it!) in Britain, but it is vitally important that it gets applied in the right places, and in the right contexts. Making our streets and roads safe, comfortable and attractive for all their potential users – particularly those with physical disability or impairment, but also everyone walking or cycling about on them – depends on it.

Posted in Uncategorized | 13 Comments

History comes full circle – Tavistock Place moving towards the cycle provision it deserves

There are a good number of encouraging cycling schemes appearing in London now, either physically on the street, or in the form of consultations and trials.

One of the latter is Camden’s plan for the Tavistock Place, or ‘Seven Stations’, route, running east-west across Bloomsbury. There’s an excellent, detailed history of the origins of this cycling infrastructure from David Arditti here, which is well worth reading if you haven’t already done so (and probably worth reading again, even if you have).

Given the present-day consensus on cycling infrastructure, I think it’s hard to imagine just how radical this rather narrow two-way track was at the time it was built, and David’s piece gives a good account of the struggles and difficulties that were faced in implementing it.

But fifteen years on, it is a victim of its own success – it is too popular. Around 6000 cycles pass along it on a weekday, and that’s an awful lot for a 2.5m bi-directional track with high kerbs.

Screen Shot 2015-07-07 at 21.33.34

I’ve heard some silly suggestions that this volume of cycle traffic means that the cycling infrastructure should be completely dismantled, mixing cycles back in again with the motor traffic that still uses this street. That would be killing the goose that laid the golden egg – destroying the attractive cycling conditions, free from interaction with motor traffic, that bring so many people to this street on a bike in the first place. 10,000 motor vehicles per day is far too high a level for comfortable sharing on a bike.

But something obviously has to give, and to its credit, the borough of Camden have come up with what is a really quite radical improvement, which is going to be trialled before being implemented permanently.

The trial will involve turning the existing, pictured, two-way track into a one-way track, conventionally at the side of the road, for east-bound cycle flows. If you’re cycling west, the entire existing westbound motor traffic lane will become a cycle lane.

Screen Shot 2015-07-07 at 21.57.23

The purple arrows show flow for cycling; the blue arrow, motor traffic flow. Restricting motor traffic to just one-way means only lane for motor traffic, and consequently much more space for cycle traffic.

In a neat twist, that means the street is finally going to catch up with Paul Gannon‘s original proposals from over fifteen years ago – which involved restricting motor traffic to one direction (albeit to create a genuinely wide two-way track, rather than one-way provision on each side of the street).


Visualisation by Paul Gannon, taken from his blog here

Of course this bold vision was watered down in the way David Arditti describes – two-way flow for motor traffic was maintained, resulting in the compromised narrow two-way facility that is on the street today. (It is nevertheless interesting that this compromised facility has attracted enough people cycling to make the case for present-day expansion unarguable).

The really clever part of this new trial scheme is how this same one-way arrangement is being used to actually reduce motor traffic levels, by pointing the one-way flow in opposing directions, on either side of Gower Street.

Screen Shot 2015-07-07 at 22.04.32

That means it’s no longer going to be possible to drive along the length of this street – you can’t drive (for example) into the West End from the east along it, and vice-versa, you can’t drive from the West End into Clerkenwell along it. Motor traffic levels should consequently therefore greatly reduce, on top of the reduction that will come from reducing from two-way flow in two lanes to one-way flow in one lane.

The arrangement will also prevent taxi drivers coming from the east and turning right (northbound) towards the stations on Euston road – this will remove a great deal of the collision risk at the junctions that was a problem on this route, coupled with conventional one-way flow for cycling.

Taxi drivers weren’t to blame for taking this route. Right turns are prevented on Euston Road by Transport for London in order to ‘smooth traffic flow’ along it (providing a signal for right turning motor traffic means stopping oncoming motor traffic). That has inevitably meant pushing motor traffic that should be using Euston Road onto these roads in Camden, effectively creating a gyratory system at the expense of borough roads, in order to push as much motor traffic along Euston Road as is possible. A sane solution to London’s traffic flow (all types of traffic, not just motor traffic) should involve allowing motor traffic to make right turns from main roads, instead of these kinds of arrangements, which create extra motor traffic (and extra risk) on streets that should not be carrying it.

Camden’s trial for Tavistock Place is planned to start in August, and will run for 12 months, after which it is hoped to convert the scheme into a more permanent arrangement, with stepped tracks on each side of the road, and improved crossings. With lower traffic levels, I suspect many of the existing traffic lights could be removed, replaced with priority junctions and zebra crossings, so there’s much to gain for pedestrians too. All in all it should make for a much more attractive, calmer street that is better to walk and cycle along.

The trial plans are available to view here

Posted in Camden, Infrastructure, One-way streets, Transport for London, Trial arrangements | 19 Comments

You’re not held up by people cycling – you’re held up by other people driving (and yourself)

Imagine a street that carries 14,000 cyclists a day, on the street itself. That equates to around 1,500 people cycling along the street per hour, or 25 every minute.

Imagine driving down that street. Surely a nightmare for any self-respecting driver who wants to make progress. A miserable experience. You’d never be able to overtake, what with all the cyclists trundling in front of you, often two or three abreast, taking up the whole road.

Well… no. Actually overtaking in a car on this street is pretty easy.

Screen Shot 2015-07-06 at 20.09.47

Screen Shot 2015-07-06 at 20.10.34

Screen Shot 2015-07-06 at 20.09.08

Screen Shot 2015-07-06 at 20.10.46… It’s even easy to overtake with people cycling two abreast, in both directions.Screen Shot 2015-07-06 at 20.10.17 Screen Shot 2015-07-06 at 20.10.58Even a very wide three abreast doesn’t present a significant problem.

Screen Shot 2015-07-06 at 20.10.04This doesn’t compute, surely!

How on earth can it be easy to overtake when there are so many bloody cyclists in the middle of the road?

The answer is quite simple – the reason drivers can overtake easily is because there aren’t many other drivers using this street.

Take a look at the photographs again. There isn’t oncoming motor traffic to prevent an overtake. There’s also limited on-street parking (just one set of bays, on one side of the road, in designed bays) meaning the road itself is not obstructed by parked vehicles.

Quite clearly it is other motor vehicles – both moving and stationary – that makes overtaking difficult, because a vast amount of cyclists ‘clogging’ a road doesn’t necessarily represent an impediment to motoring progress.

To compare with a British example – struggling to overtake a cyclist heading away from the camera here?

Screen Shot 2015-07-06 at 20.35.32Or here? (Looking in the opposite direction on the same street)

Screen Shot 2015-07-06 at 20.38.16That’ll be because of the large amount of oncoming motor traffic, preventing you from moving out into the opposing lane, and the amount of parking on both sides of the street, greatly reducing the available width of what is, in reality, a very wide road.

Really, how could it be otherwise? How can a human being two feet wide, on a road that is 35 feet wide, …

Screen Shot 2015-07-06 at 20.41.15…. seriously present an impediment to progress, without other big blocky things (including the vehicle that you yourself are driving) greatly reducing the space available?

In reality, hell is other drivers – not other people people cycling.

Posted in Uncategorized | 11 Comments