The Tories have submitted a
motion try and stop the roll out of 20mph.
It says:
CESSATION
IN ROLL-OUT OF 20 MPH SPEED LIMITS
Council
notes with concern the growing doubts which have been expressed over
the efficacy of the mayor’s controversial 20 mph speed zones.
At the time of writing, the Authority is halfway through this costly
roll-out, with a Speed Limit Order pending for the so-called Inner
Ring East section of the city.
Evidence
from the prototype (Portsmouth) model and anecdotal reports locally
suggest that these limits may actually make some of our roads/streets
more dangerous or are simply being routinely ignored by motorists.
Accordingly,
Council calls on Mayor Ferguson to put an immediate stop to this
programme to allow an objective assessment to be made into these
schemes. Their success should be judged in strict
scientific safety terms and not rely on some shifting, subjective,
criteria such as whether or not speed limits have a ‘civilising
effect’ on Bristol communities and neighbourhoods.
This is why I think they are oh so wrong.....
Portsmouth
They cite Portsmouth as an area where 20mph make our streets more dangerous.
Well, one has to ask where they get their information from. Because I asked the Road Safety Team at Portsmouth Council and this is what they said (see end of this post for full statement):
The
analysis shows that in the three-year period prior to the scheme there
were a total of 505 collisions. The corresponding figure for the
three-year period following implementation is 410 collisions, which
equates to a reduction of 18.8%. Across the rest of Portsmouth’s roads,
during the same period the number of collisions fell by 10.3% - from
1,618 to 1,451.
Since 2011 there has been continued reduction in
collisions within the 20mph roads. In 2011 there were 98 collisions
recorded by Hampshire Constabulary Stats19, in 2012 there were 67 and in
2013 there were 68.
In other words, there has been a 20% reduction if you compare the 3 year period before with the three year period after.
If you compare the three year period before (505 collisions in the time frame ie 168.33 per annum on average) with the last two years (67 and 68), the numbers of accidents have reduced by around 60%.
One assumes that a motion which suggests that 20mph be judged scientifically, would itself should do a basic bit of science (ie check that it has got its facts right).
Elsewhere than Portsmouth
So the
Institute of Advanced Motorists have claimed a 26% increase in accident levels in 20mph zones.
20s Plenty refute
this
So do others. They all point out that the IAM figures fail to point out that the numbers of accidents have gone up quite simply because there are more 20 mph zones.
They link to a BBC radio programme which precisely backs up what they say. Frankly, I find it utterly shocking that a serious organisation such as the IAM would produce such sloppy statistics.
I don't know if the Tories mean't this IAM report when putting in their motion (because they don't source their evidence, despite expecting others to take a scientific approach), but if they do, they should be ashamed of themselves.
Perhaps they just accept local evidence?
It did occur to me that the Tories might be saying you can only use local information on the impact of 20mph, because there are local factors which effect the outcome. This might be right.
But you'd then be in the scenario where
'you can't implement a policy because you have no evidence to back it up, and you will never get the evidence to back it up because you haven't implemented the policy'.
I do hope the Tories apply the same logic to all their policies.
Peer-reviewed science says 20mph is good
Peer reviewed science is something a little more substantial than stuff you find with 'Mr Google'.
A
report 'Go slow: an umbrella review of the effects of 20 mph zones and
limits on health and health inequalities'
Cairns/Warren/Garthwaite/Greig/Bambra University of Durham tell us
Five systematic reviews were included. Overall, they provide convincing
evidence that these measures are effective in reducing accidents and
injuries, traffic speed and volume, as well as improving perceptions of
safety in two of the studies. There was also evidence that such
interventions are potentially cost-effective.
and conclude
Twenty
mile per hour zones and limits are effective means of improving public
health via reduced accidents and injuries. Whilst there was no direct
evidence on the effects of interventions on health inequalities,
targeting such interventions in deprived areas may be beneficial.
The London Road Safety unit
A
report to the London Road safety unit (Chris Grundy, Rebecca Steinbach,
Phil Edwards, Paul Wilkinson, Judith Green from the London School of
Hygiene and Tropical Medicine) conclude:
All methods used in this study confirmed previous findings that London’s 20 mph zones have had an effect on reducing casualties.
The
time series regression analysis estimated a 42% reduction (95% CI 36%,
48%) in all casualties within 20 mph zones compared with outside areas,
adjusting for an annual background decline in casualties of 1.7% on all
roads in London. The largest effects of 20 mph zones were found for all
casualties aged 0 -15 killed or seriously injured (KSI) and for car
occupants. A reduction was evident for all
Road Safety GB
Road Safety GB produce a handy graphic
http://www.roadsafetygb.org.uk/news/3161.html
In fact, they probably won't accept any evidence at all
If you go to Place scrutiny commission meetings, you will see opponents of RPS disagreeing with any statistic or piece of information that doesn't fit in with their case. (They'd probably argue the same about its supporters). But their is no level of evidence which they will believe.
....and if the motion passed
well, what would happen? The Tories ask for an objective assessment to be made into these
schemes
One can only assume that the Road Safety team at Bristol City Council would perform such an analysis. Actually they already have - indeed they specifically agree with what I have said re national figures.
It is part of a package
Every now and again, the Tories talk the talk of sustainability. But they never actually seem to like any of the solutions.
It is obvious to anyone who recognises the vital need to maximise those travelling by walking, or cycling that we need to make it a more attractive option. Too many cyclists are intimidated off the road by cars. Too many potential cyclists do not start in the first place for the same reason. We must reverse this trend.
If we actually want to combat climate change, we have to make these changes, along with many others. 20mph fits with slowing the traffic and in doing so, encouraging cycling. The same rationale exactly applies to motoring.
And the odd other point
There is even some evidence to suggest that driving at 20mph is fuel efficient because you do less braking, gear changing etc. Not conclusive, as far as I am aware, but more than possible.
BRAKE tell us that at 20mph, your stopping distance is 12 metres. At 30mph, it’s 23 metres [Typical stopping distances, The Highway Code, 2011). The conclusion is self evident.
Bristol City Council tell us 'The most up to date and robust evidence shows 31% of pedestrians are killed if hit by a vehicle travelling at 40mph, 7% are killed at 30mph – a four-fold difference, and at 20mph the rate is lower still. '
Conclusion
There is a substantial amount of evidence that 20mph is working and reducing numbers of accidents. The evidence for the opposite is flawed.
We, as Greens, believe we need to improve the effectiveness of our 20mph zones - make them work better by the appropriate measures, be it enforcement, filtered permability, traffic calming, DIY streets or whatever.
There is no doubt we need to shift the balance on our streets away from being car dominated.
There is no doubt that we need streets for playing, streets for walking, streets for cycling, streets, in fact for the future - and we encourage measures which will achieve all of these objectives (along with better public transport!).
As such, 20mph is a vital part of the process and a vital part of the package which will help us achieve a green, sustainable transport future.
Portsmouth 20mph scheme
Summary: mature, area-wide scheme under which collisions have reduced by 18.8% on the roads where a new 20mph limit has been implemented, compared with 10.3% across the rest of the city’s streets.
Portsmouth City Council was the first local authority in England to implement an extensive area-wide 20 mph speed limit scheme covering most of its residential roads which previously had a 30 mph speed limit. The scheme, which covered 94% of the city’s residential road length, was implemented in 2008.
In terms of the some of the headline figures showing increases as a result of 20mph implementation, this is false. The difficulty here is that we must compare like for like in terms of roads analysed. Some studies have used 20mph casualty data for the years the scheme was being implemented (2007 to 2008). These studies searched for 20mph casualties rather than studying the roads themselves which means that from 2007 to 2008 the data would show an increase in casualties because there are an increasing number of 20mph roads. It is best to avoid studying this implementation phase altogether and focus on the geographical area before and after.
Analysis has been undertaken of all injury collisions which occurred in Portsmouth for the three years before the 20mph scheme was implemented (2005-2007) and for the three years after (2009-2011). Collisions occurring in 2008 have been excluded as this was the implementation year.
All injury collisions were included to ensure a large sample size and to avoid any skewing of the data where severity levels might have increased with higher speeds.
The analysis shows that in the three-year period prior to the scheme there were a total of 505 collisions. The corresponding figure for the three-year period following implementation is 410 collisions, which equates to a reduction of 18.8%. Across the rest of Portsmouth’s roads, during the same period the number of collisions fell by 10.3% - from 1,618 to 1,451.
Since 2011 there has been continued reduction in collisions within the 20mph roads. In 2011 there were 98 collisions recorded by Hampshire Constabulary Stats19, in 2012 there were 67 and in 2013 there were 68.
This period compares favourably with the reductions within the rest of Portsmouth's road network during the same period. There was a 31% reduction of collisions in 20mph roads compared to a 10.5% reduction in 30mph roads and an 11% reduction for all roads.
