Austria on Wednesday raised the speed limit to 140 kilometres per hour from 130 kilometres on two stretches of one of the country's main motorways.
On sections of the West Motorway A1, the new regulation will be valid for one year in both directions over a total length of 120 kilometers.
Transport Minister Norbert Hofer justified the trial on the basis that new technologies have made cars cleaner and safer.
"We are building motorways, not 'slow roads'," he tweeted last week as he announced the trial.
The previous speed limit dates back to 1974 and a decision is to be made in a year's time as to whether and where the higher speed limit should be allowed on a permanent basis.
Opponents of this test operation criticise the increased risk of accidents and harmful air pollutants such as nitrogen dioxides and greenhouse gases will be emitted.
France this summer lowered the speed limit on single lane main roads to 80km/h from 90km/h to reduce road deaths.