Despite the £10 daily congestion charge, London took the No. 1 spot as the most congested European city last year in a list compiled by map provider Navteq. As a result, the Energy Saving Trust is urging drivers of cars without auto start/stop systems to kill their engines when they’re not moving.

London Mayor Boris Johnson has also started an ‘anti-idling’ campaign to make sure the city meets the PM10 particulate pollution limits. As such he has allowed several boroughs in the city to fine long-time idlers up to £80. We wonder how long is a ‘long time,’ and just how they are going to enforce this, if at all.

Transport for London released a study showing that if all drivers in city centre turned off their idling engines for one minute when stationary, CO2 emissions would be reduced by 100 million kg.

Indeed, the devil makes money for idle engines.