Improving Air Quality on Congested Roads and Induced Demand

On 13 December, at a County Council session, the issue of excessive traffic causing unsafe levels of pollutants in the air was raised by Cllr Caroline Phillips. This was in specific relation to the ring-road in Nuneaton, where a bottleneck in the short route causes surrounding major roads towards the town to seize up.

You can watch Councillor Phillips raise the matter in the following video, which starts from the appropriate point.

The Councillor raises a very valid concern, that the effect of significant congestion in the area causes harm through poor air quality levels, where ‘safe’ limits of pollutants are exceeded to the detriment of everyone, but notably children walking to/from school. However, her solution to resolve the issue by ‘completing the ring-road’ (presumably creating the additional lanes that already exist for much of the road) is misguided.

It does seem to be an obvious solution – if you can’t get all the cars flowing nicely along a route, then widen that route to create additional capacity – but this apparent solution is one that has failed time and time again. There may be short-term relief, but invariably the extra capacity will encourage more people to drive, increasing pressure on the route until eventually, gridlock returns with all of its associated problems. This is a phenomenon known as Induced Demand and is the same reason why despite congested motorways being widened, they soon suffer the same capacity issues as they did previously.

There’s only one solution to improving traffic flow, improving air quality and the health of pedestrians (and all road users), and that is to reduce the number of vehicles on the road by enabling people to make alternative choices where appropriate. To do that, it is important to discourage the use of cars particularly for short journeys, and that means improving the facilities for both walking and cycling.

Discouragement from driving is a key point though – it’s all well and good improving active travel provision, but people need to see the benefit of making the choice to use an alternative means of transport. That could be accepting that some routes will be busy to a certain degree and therefore riding a bike along a protected lane that can bypass queues could be quicker; it could be through higher parking charges and reduced parking capacity; it could be through making the driving route between A and B longer, where cycling and walking can be more direct and therefore take the same or even less time than the car.

Nuneaton Ring-Road at a bottleneck point – a single (wide) lane in each direction.

With specific regard to the local ring-road, I’ve said before that I’m keen to see it changed to a one-way road, with space re-allocated to a new high quality bidirectional cycleway, and the existing footways, some of which are designated shared use at present, being reserved as the sole domain of pedestrians. The ring road is only 1.3 miles long and has no need to be bidirectional for motor traffic when it takes only minutes to complete the circuit, while making the route one way could potentially simplify junctions, improving the flow of traffic into the road.

Not only would such a redesign improve the environment for those cycling to and through Nuneaton whilst serving as a new central hub for a wider cycling network, It would also bring improvements for walking by reallocating pavement space that is currently shared to be solely for pedestrian use, providing more space whilst removing the conflict that can exist between cycle riders and pedestrians at present. In fact, if done right, a redesigned one-way ring-road with bidirectional cycling can also provide a pollution buffer to pedestrians, where traffic is moved that little bit further away from where people are walking, leading to a significant reduction in exposure to particulate matter.

Design work around improving parts of the ring-road are reportedly due to take place in 2019 as part of the plans to transform Nuneaton town centre, and I hope that the case for making it a one-way route and reallocating space to walking and cycling is not only one that can be put forward, but one that highways officers and councillors, including Cllr Phillips, can support.