National Highways has been told to come clean with air pollution data - or end the trials.
Air pollution speed limits that force motorists to drive at
60mph should end, campaigners have said, after it emerged they have lasted twice
as long as originally proposed without producing evidence they work.
Driving on stretches of the
M1, the M6, the M5 and the M602 has been limited to 60mph in a bid
to ascertain if driving more slowly helps reduce emissions.
But the restrictions, which were only supposed to last between
12 and 15 months, have now been running for more than two years, and still
there is no evidence to show they are effective.
There are questions over this scheme that the increased
congestion caused by the new speed limit may
have actually increased pollution.
Motoring groups and a former roads minister are among those now
calling on National Highways to come clean with the data or end the trials.
Braking not taken into account
The lowering of the speed limit was introduced based on modelling that
claimed it would significantly reduce the annual mean nitrous dioxide
concentrations in the affected zones.
It was suggested this would help the areas around the trials
near Rotherham in South Yorkshire; Witton in Birmingham; Eccles in Greater
Manchester and Oldbury in the West Midlands meet pollution limits one to two
years earlier than expected.
Advertisement :
9 sec
But the modelling did not take account of particle pollution
produced by braking. The policy also penalises electric vehicles which produce
no exhaust emissions and newer, less polluting cars.
More than
two years since the trials started no data has been published to support claims
it improves air quality. But the restrictions have caused huge frustration
for as part of the Smart Motorway upgrade.
On Saturday night Sir John Hayes, said: “Air pollution is a real concern but
the relationship between speed or traffic and pollution is complex. When you
have congested traffic, emissions grow.
Scheme 'may have made pollution worse'
Iain Stewart, the Conservative chair of the Transport Select
Committee, said “I’ve got a general concern about having things that evolve by
a creeping change without it being evidence based,” he said.
“I would certainly want to know if the data that they’ve
established thus far, has shown and whether that gives a justification for
these speed restrictions to be made permanent.
“I wouldn’t be in favour of doing that without there being a
strong evidence base.”
Claire Armstrong, from the campaign group Safe Speed, said the
scheme may have even unwittingly made pollution worse.
She said: “If you slow the traffic you risk creating congestion
and the more congestion the more pollution you are going to get so I would be
highly suspicious of a 60mph zone on a motorway doing anything other than
causing frustration and not reducing the pollution.”
Hugh Bladon, from the Alliance of British Drivers, also called
for an end to the trials.
He said:
"There is an obsession in this country with lowering the speed limit. They
are trying to find any excuse they can to reduce the speed limit. Lowering the
speed limit is seen as a panacea for everything but it is not.”
The AA has argued that the most polluting
vehicles, such as large lorries, were already limited to 60mph anyway,
while police forces often allowed 10 per cent plus 2mph leeway to the speed
limit, meaning drivers could still be driving near 70mph during the trials.
AA spokesman Luke Bosdet, said: “Essentially, this issue boils
down to environmental concerns versus the efficiency of the road network. Many
drivers feel that it is slanted too much towards the former.
“The key question is whether the lower speed limit needs to be
in operation all day, or whether they could be brought into force when
environmental conditions require it.
“The AA would argue that, if variable speed limits can operate
on the M25 depending on conditions, the same can happen on other motorways,
where needed.
First results released in spring
National Highways said that the policy was based on real-world driving data and
vehicle emission testing. It originally promised to publish monitoring for the
first 12 months of the restrictions on its website but has not done so.
A spokesman for National Highways: “As part of this process we
are taking a series of actions such as lowering speed limits on some roads.
Robust findings informed our decision and these 60mph limits will remain in
place until the air quality has met legal limits and will continue to do so
when the measure is removed.
“Given the complexity and amount of data needed, this requires
appropriate time to complete all the stages of the analysis process.
“National Highways is looking to produce initial reports on the
performance of the real world 60mph speed limits in spring 2023.”
