A number of research initiatives have reported newer diesel motors emit more nitrogen-oxide than older diesel engines, so drivers of shiny new cars will face restrictions.

“A driving ban on all diesel motors should be the absolute last resort,” said national driving club spokesperson Inger Elisabeth Sagedal.

Yet on some winter days, Oslo air is as hard on children, asthma sufferers and those with cardiovascular diseases as some of China’s worst industrial centres, city officials have said.

Doctors are understood to be among the experts called on to convey citizens’ health needs to the expert committee drawing up vehicle restrictions on key road arteries.

“Here is a chance to put together things that have a real effect,” Geir Endregard of the Astma og Allergi Forbund (Asthma and Allergy Association) told broadcaster NRK.

“(Diesel engines) are the big bad wolf when it comes to air quality,” he said.

The city experimented with closing its streets to diesel emissions in February 2011, when the last digits on licence plates determined whether a vehicle could enter the city on days when the air was “acutely bad”.

This year, a number of actions are being considered: making all diesel-driven cars stay away; a ban on all personal cars burning diesel; no driving alone in a diesel-powered car and no heavy transport through the city.

In the lead-up to a ban next winter, southern Norway’s chronically late rail and overburdened buses and trams will have to expand services, and it is uncertain whether managers will cope. There is too little time to expand the number of parking spots at suburban train stops for an experiment this winter, but the licence plate numbers game is seen coming into play again as heavy, frozen mists laden with pollutants again seize the city.

Nitrogen-oxide, a formidable ozone killer and the curse of the shipping industry, has increased in concentration over Oslo in the days since particle filters were introduced for diesel motors.

Sagedal said her driver organization, NAF, understands the link between diesel motors and health, “but a ban on diesel driving in winter is the worst solution”. She told NRK trying to improve public transport solutions first was the right move.