It is a hot and muggy morning and the street is already full of traffic. You pull in to the kerb on a single yellow line and your wife gets out and nips into a convenience store. There are no parking spaces in sight and the children are getting restless in the back seat. What is more natural than to sit and wait a few minutes with the air-conditioning on and the engine running until she comes back?
It is a scene familiar to many motorists in Hong Kong but one that could soon become a driving offence under government proposals for a ban on idling engines. The move is among a series of measures to tackle the city's worsening air pollution being launched by Chief Executive Donald Tsang Yam-kuen, who has pledged to put concern for the environment at the heart of his policymaking.
It comes as a number of cities and regions around the world enact similar bans in efforts to improve air quality for citizens and help meet United Nations emissions reduction targets.
Earlier this month, the Canadian capital Ottawa introduced a ban on motorists idling their engines for more than three minutes that comes into force in September backed with a C$100 (HK$720) fine.
In southern Taiwan, a ban will be introduced next January which also sets three minutes as the limit, while Scotland's second city Glasgow, which launched a ban in 2004, recently began imposing #20 (HK$310) fixed-penalty fines after drivers failed to respond to a 'softly softly' approach based on persuasion.
In Egypt, tourists visiting the pyramids near Cairo now have to switch off the engine or face being charged with 'damaging archaeological sites' after an idling ban was imposed around the Saqqara site last October.
The Egyptian authorities said the action was necessary because the idling of tour bus and car engines had caused cracks in the Djoser pyramid, which is considered the world's oldest large-scale stone monument.