Lower speed limits for cleaner air look set to be here for good
LOWER speed limits for cleaner air on five Welsh trunk roads are here to stay and could be extended, with electric cars unlikely to be exempted.
The Welsh Government reduced the limit from 70mph to 50mph in 2018 on five sections of dual carriageway to reduce the nitrogen dioxide (NO2) pollution which affects nearby residents.
Average speed cameras were installed in 2019 and compliance with the speed limit quickly improved, resulting in large reductions in NO2 concentrations.
So far, drivers have not been punished for exceeding the limit, but from today they will receive “advisory letters”. Police plan to issue speeding fines later.
Owners of electric vehicles (EVs) will not be exempted from penalties, despite not contributing to the NO2 pollution around the affected roads. The fact that the car is an EV will not be a valid defence for anyone caught speeding on those roads, because 50mph is the legal limit for all vehicles, regardless of the limit’s purpose.
Before the pandemic, the Austrian government announced it would exempt EVs from speed limits which are reduced specifically to tackle air pollution. One minister said the measure would incentivise drivers to switch to electric cars.
However, the Welsh Government said it has no plans to allow EVs to travel legally at 60mph or 70mph where diesel and petrol vehicles are limited to 50mph.
Motoring groups are sceptical about two-tier speed limits. Jack Cousens, the AA’s head of roads policy, said: “I think that would confuse people. It’s not a good driving experience if you’ve got two different speed limits for going in the same direction.”
Different speed limits on the same roads apply to certain classes of vehicle, such as lorries and coaches. Mr Cousins said those vehicles tended to travel slower than cars.
He expected the Welsh 50mph limits for NOX reduction to remain in place until so many people had switched to EVs that increasing the limit to 60mph or 70mph would not result in NO2 limits being breached.
Tim Shallcross, IAM Roadsmart’s head of policy, said Automatic Number Plate Recognition cameras would be able to enforce different speed limits for EVs and other vehicles on the same roads.
He said: “It poses something of a safety problem if I’m driving to the 50mph speed limit in the outside lane to overtake some trucks, and somebody else who is allowed to do 70mph is on my bumper wanting to go faster because legally they’re entitled to.”
Exempting EVs could lead to objections from owners of diesel cars which meet the Euro 6 specification, with “extremely low” emissions of nitrogen oxides, said Mr Shallcross. “Someone in a Euro 6 car could argue, ‘Why shouldn’t I be able to do 70mph as well? It’s all those polluting people in Euro 4 and Euro 5 cars who should be keeping their speed down.’”
The Western Mail understands that officials are looking into the possibility of reducing the speed limit from 70mph to 50mph on two other sections of road to improve local air quality. One is the A470 between Coryton interchange and Upper Boat, the other is a further section of the M4 near Port Talbot.
The A470 from Upper Boat to Bridge Street interchange, Pontypridd, already has a 50mph limit to reduce NO2 pollution. From 2018 to 2019, there was a 46% reduction in annual mean NO2 alongside that section of the A470.
The M4 at Port Talbot has a 50mph limit for air quality between junctions 41 and 42, where NO2 reduced by 42% from 2018 to 2019.
The other roads with 50mph limits for air quality are the A494 from the border to St David’s Interchange, Flintshire, the A483 between junctions five and six at Wrexham, and the M4 between junctions 25 and 26 at Newport.
Research by the European Environment Agency and Welsh Government has shown that reducing traffic speeds to around 50mph has produced other reductions in pollution. Driving at 50mph instead of 70mph was found to promote consistent speed, with less braking, accelerating and pollution. It also reduces turbulence and the spread of road dust and other particulates in the air. These pollution reductions apply to EVs as well as to petrol and diesel vehicles.
Driving at 50mph instead of 70mph also reduces energy consumption, including by EVs. There is a carbon benefit from driving EVs slower because not all of the electricity used to charge EVs is produced by renewables.