STOCKHOLM (Reuters) -- Carmaker Volvo has asked for special exemption from Sweden's tough drink-driving laws so its test drivers can have a glass too many to test new safety systems that warn if a driver is not reacting to danger.

Volvo, whose success rests on its reputation for building safety-conscious family cars, will only let its drunk drivers take the wheel on its own test tracks near the west-coast city of Gothenburg if it gets permission from the Swedish government.

"It's a matter of developing technical systems that warn if the driver isn't reacting properly," said Christer Gustafsson, spokesman for Volvo Cars, which is owned by Ford Motor Co.

"That means if the driver is tired, sick, drunk or under the influence of other drugs. We want to do this in a controlled environment in Sweden," he told Swedish news agency TT.

The new safety system is still at the development stage and Gustafsson said he could not give more details about how it works. "It's all about preventing accidents," he said.

Sweden has one of the best road-safety records in the world thanks partly to drink-driving laws which are among the toughest in Europe. The laws apply to private and public roads.

Stockholm County Traffic Police said the most drivers could drink without risking a heavy fine is one beer, while drivers caught well over the limit can be sent to prison.