Drivers face fines for leaving their engine running
Drivers who don't cut their engines when waiting aren't just wasting fuel: they're breaking the law and risk being fined.
An idling engine can produce up to twice the emissions of a car in motion, churning out sulphur dioxide, particulate matter and nitrogen oxide.
All of these contribute to asthma, heart disease and even lung cancer, according to Transport for London.
These chemicals also have a negative effect on the environment by contributing to poor air quality.
So, to reduce the impact of these harmful pollutants, governments across the UK have introduced laws to discourage drivers from idling.
In England and Scotland, leaving your engine on while parked on the road or in a public place could land you with a fine.
This can be as much as £80 in certain areas of London where there are extra measures to cut emissions.
Wales has also introduced fines for idling, except their rules extend to drivers leaving their engines running in stationary traffic.
The Welsh Government is also proposing Low Emission Zones and fines for drivers with high polluting vehicles as part of their Clean Air Bill.
So how can you avoid getting a fine for idling?
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Is it illegal to let your engine idle?
Stationary idling is an offence under section 42 of the Road Traffic Act 1988.
The Act enforces rule 123 of the Highway Code, which states: "You must not leave a vehicle’s engine running unnecessarily while that vehicle is stationary on a public road."
Doing this can incur a £20 fixed-penalty fine under the Road Traffic (Vehicle Emissions) Regulations 2002. This goes up to £40 if unpaid within a given time frame.
But this is only imposed if the driver fails to turn off their engine when asked to do so by a marshal.
Does the ban on idling extend to private land?
The rules over stationary idling apply to public roads.
It’s local councils rather than the police that issue penalty charge notices (PCNs). And you’d only get one of these if you refused to switch off your engine.
London’s Islington Council mounted what's thought to be the first crackdown of its kind on vehicles churning out "unnecessary pollution" in 2014 and then again in 2016.
In early 2018, Westminster Council launched its #DontBeIdle campaign in an effort to kerb idling in the borough.
How much pollution does an idling car create?
"An idling engine can release as much pollution into the air as a moving one," says Islington councillor Claudia Webbe.
"Cutting the engine while stationary reduces both the harmful pollutants being released and saves on fuel."
It’s a common misconception that turning your engine off and on again uses more fuel than leaving your car idling.
And increasingly, manufacturers offer "stop-start" technology as an option on new vehicles.
This means the engine automatically cuts as you come to a standstill and restarts when you apply the clutch.
If you drive an older car, it’s wise to plan ahead rather than turning your engine on and off. Doing so could affect the battery especially if it’s over five years old.
Along with the laws on idling, the government have also introduced other measures in an effort to improve the air quality in the UK.
A higher tax on diesel cars was introduced in an attempt to reduce nitrogen oxide (NOx). And in 2030, sales of new petrol and diesel cars will be banned.
It’s thought that speed humps also contribute to emissions, so new forms of traffic calming are now being considered.
What should you do?
If it looks like you’re going to be waiting for more than a minute then it’s best to switch the engine off.
Turning your car off while loading and unloading your vehicle, waiting at car parks, lay-bys or set down and pick up points will also help tackle emissions.
What about in hot or cold weather?
On the rare occasion where you might be in a heatwave, keeping the air-conditioning on can seem like a vital reason for idling.
Usually you can keep the air conditioning running by leaving the ignition on but not the engine. If there’s no other choice but to leave the motor running you should try and keep waiting down to a minimum.
The exception to the rule is if you need to defrost your windscreen.