VDA on 30 km/h Speed limit

Extending the 30 km/h speed limit beyond the existing areas will not automatically lead to lower emissions. On the contrary, vehicles travelling at 30 km/h generally use a lower gear, which tends to result in higher consumption and CO₂ output. In addition, it has been shown not to reduce nitrogen oxide emissions. It would be more expedient to apply measures enhancing the steady flow of traffic. Combining a 30 km/h limit with crossings giving priority to traffic from the right can end up being counterproductive.

If a speed limit of 50 km/h and the associated time savings disappeared on the main roads, many motorists would leave the arterial routes and take side roads instead. Using back roads and the resulting increase in traffic through residential areas would adversely impact road safety and noise pollution. For local public transport a standard 30 km/h limit might cause lost time and thus lead to the deployment of more vehicles and personnel, which reduces the competitiveness of bus services.