Are UK Smart Motorways Increasing Rather Than Reducing Air Pollution?

The UK’s smart motorways utilise certain traffic management methods that help lower congestion in busy areas. Created by Highways England (formerly known as the Highways Agency), these motorways are also intended to reduce the impact of traffic on the environment, among other things. The first smart motorway was launched 15 years ago near Birmingham.

Despite the clear-cut goals of the motorways, they are continuously under scrutiny by motoring experts. Earlier this year, complaints surfaced about the smart motorways’ unwelcome contribution to air pollution.

According to a post-opening project evaluation published by Highways England, greenhouse gas emissions in smart motorways is almost double the anticipated amount after one year of operations. While initial appraisal during the implementation of the scheme predicted an increase in carbon emissions because of expected traffic flow changes, the greenhouse gas emissions for the opening year reached levels higher than the forecast numbers. From 2017 to 2018, CO2 or carbon dioxide emissions were at 211,881 tonnes, way higher than the predicted 196,660 tonnes. The focus of the evaluation was the “all lanes running smart motorway scheme”.

Transport Action Network Director, Chris Todd, pointed out that the smart motorways opened new roads, which led to new traffic. Anytime this happens there is bound to be an increase in emissions. At a time when the need to drastically reduce air pollution is top priority, the motorways emissions increase is not a welcome development.

For its part, Highways England noted that while the scheme effectively brought down the volume of road users, there was a marked increase in the volume of heavy goods vehicles on the roads. This is a significant factor in determining the level of carbon emissions. They will use the evaluation to further analyse the scheme’s longer-term effects before coming up with a conclusion for the Smart motorways’ overall impact.

Their goal is to come up with actions that can counter the adverse effects of the scheme on the environment, particularly toxic emissions. A Highways England representative also reiterated the group’s active role in the UK’s goal of ensuring a low- to zero-carbon future.

The smart motorways and their uses

Smart motorways use specific technologies to track and manage traffic. There are cameras, sensors, and signs, and other traffic management methods such as variable speed limits and using hard shoulders for running lanes.

These smart motorways are divided into three types:

  • Controlled Motorways – similar to traditional motorways; uses hard shoulders for emergencies but utilizing different speed limits; also has active lane management signs
  • All Lane Running Motorways/Schemes – also known as ALR, this scheme closes lane one (or what used to be the hard shoulder) only if there is an incident; hard shoulders are permanently removed; so when there is an emergency, vehicles are directed to a bay on the left area of the inside lane considered as the emergency refuge area
  • Dynamic Hard Shoulder Motorway – a hard shoulder may be opened during busy times so capacity can be increased; this scheme might be transformed into an ALR motorway by 2025

Smart motorways and the emissions scandal

While they are two entirely different things, both the smart motorways and the emissions scandal that started in 2015 have adverse effects on the environment. Vehicles driving through the motorways contribute to CO2 emissions, while the car manufacturers involved in the diesel emission scandal emitted high levels of nitrogen oxides. Both are dangerous for the environment and human health.

Carbon dioxide, the primary type of greenhouse gas, is responsible for large volumes of emissions. CO2 emissions can cause climate change leading to serious problems such as wildfires, disruption of food supply, and extreme weather conditions.

Exposure to CO2, even at low levels, can lead to health issues such as bone and kidney-related problems, reduction in cognitive performance, and inflammation. Individuals exposed to CO2 may also develop respiratory problems as a result of air pollution.

Nitrogen oxides or NOx are harmful gases released by diesel vehicles. They contain nitric oxide (NO) and nitrogen dioxide (NO2), which are responsible for the formation of smog, acid rain, and ground-level ozone. NOx also has particulate matter, particularly PM2.5 or fine particulate matter. PM2.5 can easily penetrate deep into the lungs and cause a variety of lung problems.

Health issues that can develop from exposure to NOx include breathing problems, asthma or aggravated asthma, other respiratory issues; and in severe cases, cancer and premature death.

The diesel emission scandal implicated that Volkswagen, Mercedes-Benz, and other car manufacturers used defeat devices to cheat on emissions tests and lied about the environmental safety of their diesel vehicles. In lab tests, the emissions levels were at legal levels. But in real-world driving conditions, they were way over the World Health Organization and EU legal limits. The Volkswagen and Mercedes Benz emission scandal continue to cost both car manufacturers millions in fines, compensations, and car recalls.

You can help

Whether you use smart motorways regularly or not, you can help the government reduce air pollution. If you have a Volkswagen, or Mercedes-Benz, or any of the vehicles alleged to have defeat devices installed, file a claim against your manufacturer. Find a team of emission compensation experts who can help you go through the Mercedes emissions claim process.

The experts at are experienced in handling even the most complex emissions cases. You need to get in touch with them.

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