Germany's Chancellor Angela Merkel has rejected a call from her Social Democrat (SPD) coalition partners for a speed limit on the country's motorways.
German drivers cherish their freedom on the Autobahn
At its party congress on Saturday the SPD voted in favour of a 130km/h (80 mph) speed limit to help reduce greenhouse gas emissions.
But Mrs Merkel told German ZDF television that "this is not going to happen with me".
"Traffic jams are at least as harmful to the climate as speeding," she said.
In March, the German government rejected a call by EU Environment Commissioner Stavros Dimas for Germany to impose a speed limit on its motorways, or Autobahnen.
Unlike its EU neighbours, Germany applies motorway speed restrictions only in traffic bottlenecks, near road works or in particular circumstances.
German car firms such as BMW, Mercedes-Benz and Volkswagen take pride in their high-performance models, seen as symbols of the German export boom.
The manufacturers have defended the traditional policy on motorway driving.
Environment Minister Sigmar Gabriel of the SPD said a speed limit would only cut carbon dioxide (CO2) emissions by 2.5 million tonnes annually, whereas a cut of 270 million tonnes was needed.
Focus on jobs
The SPD congress committed the party to "democratic socialism", in a programme that German media described as a shift to the left.
The congress decided in favour of paying unemployment benefit to older claimants for longer than previously.
SPD leader Kurt Beck got strong support from delegates.
The SPD has been trailing significantly behind Mrs Merkel's Christian Democrats (CDU) in opinion polls. It has been in a left-right "grand coalition" since November 2005.
Mrs Merkel told ZDF that she remained committed to reducing labour costs for employers and creating more jobs.
"We've found that changes have brought results, so we must do what is necessary to create jobs. That will be my standard, and I'm sure I can convince all members of the government about that, including the SPD members."