Sunday 1 November 2009

“It’s the speed of motor vehicles stupid”

The following article was published by ACT Travelwise in their recent newsletter

“It’s the speed of motor vehicles stupid”


In 1992, during the American presidential campaign Bill Clinton had a sign in his office proclaiming “It’s the economy stupid”. At the same time the German town of Hilden in North-Rhine Westphalia on the outskirts of Dusseldorf was looking at its falling cycling and pedestrian numbers. The urban planners recognised that the safe mobility of their citizens was one of the key tasks of municipal self determination. Their conclusion was that “It’s the speed of the motor vehicles stupid” and they introduced 30 kph (18.5 mph) speed limits on all residential streets and some main roads. They did so with a great deal of public engagement and appropriate police enforcement. Their reasoning was that reducing the differential speed between road users that was the biggest factor in road danger reduction. And now with 24% of in town trips by bicycle and 25% by public transport they have a successful and sustainable transport model that some UK towns would die for.

So many of our towns in the UK are blighted by policies which see transport issues in terms of the movement of motor cars rather than people. And if we look at the percentage road deaths that are pedestrians, then in 2005 in the UK it was 21%, one of the highest in Europe. And since then it has risen to 21.3% in 2006, 21.9% in 2007 and 22.5% in 2008.

When the DfT found that we were being knocked off our previous Road Safety pedestal by France and Finland and Japan and Sweden and Germany and Portugal and the Netherlands and Denmark and Switzerland, who all now have lower child road deaths per 100,000 population than the UK, then the alarm bells started ringing. Its recent “A Safer Way” White Paper recommended that “highway authorities, over time, introduce 20 mph zones and limits into streets that are primarily residential in nature”.

A reduction in perceived road danger is key to any significant promotion of cycling or walking. Almost half of the public questioned (47%) strongly agree that “the idea of cycling on busy roads frightens me”, with a further 27% agreeing with this.

Whilst we can attract some new “fit and brave” cyclists onto the roads and also create off road routes that may work for a few people who live in the right place, unless we address this very real fear then any progress on modal shift will have limited returns.

And of course, unless we can get towards 20% of all in-town trips being made by bicycle then we fail to make any real reduction in the unsustainable transport to which those initiatives are targeted.

We need a “paradigm shift” in our thinking which starts to recognise that the spaces between houses that we call streets are there to be used equitably by all, regardless of their wealth, health, age, or choice of transport mode.

We need to ask ourselves how moral it is to promote walking and cycling if at the same time we do not make our streets safer places for people to cycle and walk.

We need to ask whether “speed becomes greed” when it keeps the elderly in their homes and our children “bussed” to schools by parents through fear of traffic.

And in town halls throughout the country these questions are being asked and there is gradual recognition that “It’s the speed of the motor vehicles stupid”.

Portsmouth was the first city to take advantage of the changes in the DfT Guidance in 2006 which lowered the “before” speed threshold for implementing 20 mph speed limits without traffic calming. The circular also recommended the use of 20 mph speed limits in residential areas and in the vicinity of schools where there is a high presence of vulnerable road users.

In2008 Portsmouth completed the setting of 1,200 residential streets at a 20 mph speed limit. The cost was just £475,000 or £333 per street. And now the DfT have reported on its audit of the 1st year of operation with results which show a 7 mph drop in average speeds on roads where previously the average was above 24 mph. There was also a 15% reduction in casualties. Ongoing audits will confirm the effect of this “collective community commitment” to safer roads on cycling and pedestrian activity.

The reduction in speeds is also leading to the delivery of contraflow cycling on one-way streets so increasing cycling permeability and accessibility. There is also evidence that air-bourn PM10 diesel particulates are reduced at 20 mph .

And it’s not just Portsmouth. Local authorities representing over 1.5 million residents in the UK are now in the course of implementing 20 mph as the default speed limit for all residential streets. And in doing so their communities are debating just how they want to create a better environment for children to walk and cycle, for the elderly to shop and for everyone to have real choice in their transport choices.

Such a move is hardly controversial, with over 75% of drivers in favour of a 20 mph limit for residential streets .

Whilst we cannot do anything about the mistakes of the past, we can all start to create urban road networks that recognise equality and respect the safety of all our citizens. The time has come for communities to demand that “20’s Plenty where people live”.

3 comments:

  1. The Portsmouth Interem Report showed a 0.9mph reduction in overall average speed, with 14 sites found to have speeds between 24 and 29mph after the scheme was implemented. This is not startling - research from the 60s and 70s showed that lowering a posted limit had a marginal effect on the 85th percentile traffic speed.

    As you say on your website, traffic often travels below 30mph already due to bends, blind spots, junctions, crossings etc.

    Most people are in favour of low limits for residential streets, but Oxford took the chance to apply the limits area wide, including large, well sighted feeder roads. Doing so weakens the significance of the 20 limits where they are needed.

    The Government's "design of streets" manual already covers this. There's a section devoted to controlling traffic speeds by road design. Just putting 20 signs up on a road where a majority think 30mph is acceptable leads to wide scale flouting of the speed limit. This is why it was previously necessary to change the road layout when lowering the limit.

    It's all very predictable. A 20 campaign will never achieve a decent change. Those who ignore current good practice will ignore 30 limits and 20 limits. Meanwhile you frustrate and insult the intelligence of another set of road users. You lower the value of 20 limits where they are needed.

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  2. Tom

    The Portsmouth interim report showed that the average speed on faster roads (where the before ave speed was > 24 mph) dropped by 7 mph.

    Yes, traffic often travels slower than 20 mph. It also travels faster and that is what communuties want to reduce.

    I respect the fact that there may be a difference between where you think 20 mph speed limits are needed and where communities think they are needed. But if a community democratically decides that a limit should be reduced then it is their view which counts and not yours.

    In Portsmouth they found a far better and more cost effective way than changing road design. It is called changing driver behaviour.

    Are you saying that a 7 mph reduction oin speeds on faster roads is not "decent change". I think that the people of Portsmouth would disagree with you.

    I suspect that your objections all revolve around where you think 20 mph speed limits are necessary. You want them in as few places as possible, but 75% of the British public (British Social Attitudes Survey 2005) want them for residential roads.

    Best regards
    Rod King

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  3. Most drivers don't want an accident to happen, so adjust their speed to conditions. Most travel at below 30mph when they think it is sensible. Most also ignore limits if they seem out of line with what they think is reasonable.

    My experience of 20 limits is that they achieve very little. The thinking is usually muddled too - local residents say that traffic is too fast, meaning that a proportion of vehicles are travelling too quickly for conditions. This is usually above the current posted limit. They think that speeding traffic travels at a fixed offset above the limit, so a lower limit will reduce the speed of speeding traffic. All a waste of time. Read the research from the 60s onwards.

    "But if a community democratically decides that a limit should be reduced then it is their view which counts and not yours."
    Fine, but you'll find that if a significant number of people disagree with this they'll ignore the limit.

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