Leaving your engine running in Wales could cost you £150
The previous punishment for idling was £20 and had not changed since its introduction in 2003
Drivers in Wales who leave their vehicle engine running while parked will face fines of up to £150 from Wednesday.
The change is part of a new measure by the Welsh government to try to reduce harmful pollution and to protect children's health.
The previous punishment for idling, as it is known, was £20, but that has now been raised to anywhere from £75 to £150, depending on circumstances.
The Welsh government said it hoped the increase would "change the habits of people who are polluting communities".
Llyr Gruffydd, cabinet minister for rural resilience and sustainability, said the £20 fixed fine for idling was "insufficient", and not being used "in the way everyone might envision it".
Increasing the fee that is available for local authorities to penalise drivers will be a "stronger deterrent", he added.
"We really do feel we need to step up here, clamp down on this as a problem and make sure we protect people's health and generally it will make communities a better place to live in."
Gruffydd said he hoped the higher range of fines would "change the habits of people who are polluting communities and are putting children and vulnerable people's health at risk".
Chiara (left) and Wendy (right) agreed it was a good principle, but not everyone thinks it will be enforced
Anna, who was collecting her children from Treganna school in Cardiff, welcomed the new measure.
She lives close to the school and said it got "really, really busy because cars are everywhere around here".
"When we actually want to leave here, to go somewhere, we can't during these hours," she said, adding it once took her 45 minutes to get down the road.
"For us it's kind of good because it will stop a lot of these cars from parking here."
Chiara Rinaldi, another parent, said: "I think they probably have a good principle behind them but I think the reality is nobody is going to enforce them.
"School runs are chaotic as it is but you're never going to get the police out here are you, enforcing fines.
"It's a great idea but never going to happen."
Rhiannon Simmonds says she is not sure she agrees with a "mandatory solution" to the problem
One parent who frequently collects her children from school on foot is Wendy Vernon-Fulook, and she believes the higher fine is a "good thing".
"You shouldn't be leaving the car running, obviously it's not good for the environment and it might stop people from doing it.
"It might not, people might keep doing it unfortunately, but we're trying to encourage people to walk as much as possible, so it can only be a good thing."
But Rhiannon Simmonds said: "I'm not sure I agree with it, if a mandatory solution is the way to go about it, but I completely appreciate the logic of what they're trying to do for sure."
What are the rules around idling?
Under rule 123 of the Highway Code, drivers must not leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while that vehicle is stationary on a public road.
Areas outside schools have been identified as high risk sites where emissions pose particular concerns.
Hospitals, GP surgeries, care homes and other healthcare facilities are also identified as high risk locations.
Professor Isabel Oliver, chief medical officer for Wales, said air pollution was a serious public health issue that contributed to a range of conditions including heart and lung disease.
"Children, older people and those with existing health conditions are particularly vulnerable to its effects," she said.
"Idling may seem like a small, everyday habit, but it adds up.
"Every time an engine is switched off rather than left running, we reduce the amount of harmful pollution in the air we all breathe, particularly around schools, hospitals and other places where vulnerable people spend time."
This new measure comes into force following a vote at the Senedd in March.
MSs passed the new rules, with 37 politicians voting for and 12 against. There were no abstentions.
