What to say to people idling their engines

By Emily Kerr

Emily Kerr is the founder of Share Our Cars, an advocacy group that helps people to share cars with neighbours and reduce private car ownership. 

Engine idling consumes around 1.6% of our total fuel. It’s a significant contributor to air pollution, and it’s illegal in the UK. An RAC survey in 2019 found 26% of people have noticed engines idling outside schools, and 72% of drivers think councils should enforce it better. But many people still do it.   

I recently thanked an Amazon delivery driver for not idling. He told me that it was now impossible to do on the new vans, and that he’d heard that Amazon were saving at least £2m in petrol costs by replacing their old fleet with ‘stop start’ engines. These result in a 5-7% improvement in fuel economy. Commercial vehicles idle for 96 minutes/day on average, and with around 4.5 million of them, this costs upwards of £3billion per year in petrol costs in the UK alone. Idling burns money, as well as polluting the air.

People know they shouldn’t idle. Last month, somewhat incensed by the amount of pollution caused by idling engines and trapped by our tall buildings in Oxford, I decided to ask every driver I saw idling to stop. Because I don’t like confrontation, I decided to read about behavioural approaches which might work before I started. Here’s what I learned worked best: 

1. Start with a wave and a smile (makes people more likely to be helpful) and a gesture of key turning off. Drivers are used to signals (e.g. people raising their hand to say thanks) – it’s a normal way to communicate with someone inside a car. This often works on its own. Whatever you do don’t knock on the car. It doesn’t go down well!

2. If driver rolls down the window, be polite and direct in your request (“would you mind turning off your engine?”) and also give a sensible and non-confrontational reason for why you are asking. This is because people often respond to a logical reason which they couldn’t have been expected to know about. For example, I might say “there are lots of children at exhaust height on this road” or “the houses here are really high and they trap the noise so it’s very loud inside”. These reasons help justify why I am asking, and give the driver a reason to comply politely with a request. Saying “It’s illegal” or even “it’s bad for the environment” are bad reasons, because they inherently imply that the driver is a bad person and therefore set up confrontation. 

3. Say “Thank-you” and move away before the driver has decided whether or not to turn the engine off. This actually increases compliance AND reduces confrontation. When the engine is turned off, I give a thumbs up to the driver often without turning around.

Therefore, a typical encounter should go something like this. 

Smile and wave at driver, make eye contact, mime turning key off. If driver turns off engine, smile and give a raised hand thanks or thumbs up. If driver rolls down window, keep smiling.

Politely ask “Would you mind turning your engine off? It’s nursery pick up time and there are about to be a lot of small children on this road. Thanks!” Immediately walk away, and then raise hand to indicate thanks or give thumbs up if engine is turned off. If they don’t turn the engine off, no big deal, you haven’t lost anything.

In February, I asked about 30 drivers and had 100% success rate using this approach. Interestingly, almost all of them were men, many in delivery vehicles. As I am only going on my own experience, I don’t know whether they would be less likely to comply if it was another man asking. After my month of committed asking, I now don’t ask every single driver, but I would say I probably still ask around 80%. Drivers are generally friendly and obliging. They’ve just forgotten.