Speed limits may also be set to reduce the environmental impact of road traffic (vehicle noise, vibration, emissions) and as a political response to local community concerns for the safety of pedestrians. For example, a draft proposal from Germany's National Platform on the Future of Mobility task force recommended a blanket 130 km/h (81 mph) speed limit across the Autobahn to curb fuel consumption and carbon emissions. Some cities have reduced limits to as little as for both safety and efficiency reasons. However, some research indicates that changes in the speed limit may not always alter average vehicle speed.