Germans are driven to slow down: Fear of air pollution is causing motorists to respect speed limits, reports Adrian Bridge in Berlin

Drivers entering the German state of Saxony-Anhalt earlier this week faced an unusual request - to slow down, calm down, and thereby help to bring down a dangerously high level of ozone pollution in the air. Amazingly, in a country where freedom is commonly equated with being able to race along motorways at speeds of over 200kph (120mph), most people obliged. According to police, over 90 per cent of all drivers stuck to the suggested motorway speed limit of 80kph (50mph), even though none faced punishment if they chose to disregard it.

The Saxony-Anhalt experiment followed soon after one conducted in Hesse last week and an even stricter trial run in Baden-Wurttemberg early last month. The fact that so many drivers stuck to the speed limits surprised both critics and supporters.

It also prompted the Social Democrats (SPD) to call for the imposition of permanent speed limits on all German motorways, in line with every other European country. 'What we need are speed limits 365 days a year,' declared the SPD leader, Rudolf Scharping. 'The time for patchwork solutions is over.'

In addition to reducing smog, the SPD argues that a motorway speed limit, set at 130kph (78mph), would bring down a high accident rate. 'Fast driving obviously results in more deaths on the roads and higher pollution. But it remains to be seen whether most people will accept that argument,' a party spokeswoman said.

In a country where nearly everybody entering a motorway turns into something of a Formula 1 racer, the SPD's tactics could backfire. Yesterday Klaus Kinkel, the Foreign Minister, accused the SPD of an 'inappropriate over-reaction' to the summer smog scare. Other government representatives accused the SPD of wanting to impose rigid regulations.

Given the high level of support for the temporary speed limits in Hesse and Saxony- Anhalt, however, these arguments have lost some of their force. Opinions polls suggest that, for the first time, most Germans may back limits.

'At last people are beginning to make connections between exhaust fumes and pollution,' said Michael Korwisi, spokesman of the Hesse Environment Ministry, which imposed an unprecedented 'smog alarm' last week. 'And it is now clear that they are willing to share responsibility for trying to reduce it.'

Ozone on the ground, as opposed to the protective ozone layer in the atmosphere, is a harmful pollutant resulting from a combination of sunlight, nitrogen dioxides and hydrocarbons from car fumes. High concentrations cause coughing, eye and throat irritations and can bring on asthma attacks and lung problems. The decision to declare the smog alarm was taken after three monitoring stations in Hesse registered ozone levels of more than 240 micrograms per cubic metre of air - double the amount that the World Health Organisation says is damaging to health.

On the day after the speed limit was introduced, Klaus Topfer, the Environment Minister, said it was a symbolic act, which would have almost no impact on ozone levels; these could only effectively be reduced by improving the quality of petrol. Another political opponent described the initiative as a 'failed PR gag'.

Joschka Fischer, Hesse's Environment Minister and a leading Green, not surprisingly denied such charges, although the results of scientific tests on the drop in ozone levels, as a result of the speed limits, will not be ready for three to five weeks.