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    Air Quality event
    ​A Clean Air Champion talking to a supportive driver
    Air Quality logo

Why are idling vehicle engines a problem in the City

Leaving a vehicle engine running when parked causes unnecessary air pollution. The Square Mile is an Air Quality Management Area so action to reduce emissions is paramount. The City Corporation therefore asks drivers to switch off of their engines when parked for a minute or more.

​Idling Engine Action Days

To help change behaviour in the long term in 2015 and 2016, idling engine action days were held in the City where trained City residents, partners and staff patrolled the streets asking drivers to switch off when parked.

In October 2016, action days were rolled out across 11 additional boroughs with the support of the Mayor's Air Quality Fund.

The Action Days continue to receive wide media coverage including BBC Radio 4, BBC's 'The One Show' and BBC London.

Please visit Idling Action and email if you would like to get involved in this behaviour change campaign.

How the City Corporation helps

  • Writes to specific companies regarding idling engines
  • Works with City businesses, including the Cheapside Business Alliance and Bart's Health to support 'no-idling'
  • Engages with construction and streetwork sites to encourage and enforce 'no-idling' deliveries and site management
  • Has incorporated no-idling into the City's Procurement Policies
  • Responds to complaints and logs hot-spot areas for targeted action (placing signs asking drivers to switch off)
  • Utilises Street and Civil Enforcement Officers to enforce the no-idling message

​Fixed Penalty Notices

Although the City Corporation has focussed on awareness raising to change behaviour in the long term, the City Corporation also has an enforcement role. Subject to certain restrictions, any driver of a motor vehicle parked on the highway who refuses to switch off their engine if asked by an authorised officer can be issued with a Fixed Penalty Notice.

The £20 fine must be paid within 28 days, after which the fine increases to £40.

If you are aware of any areas of the City that vehicles are regularly left idling, please notify the pollution team on 020 7332 3030 or email