The reason for reducing Zurich’s speed limit was first and foremost to reduce noise pollution.
The pilot project, which ran from 2010-2012, involved a night-time speed limit. Switzerland's government is currently discussing 50 and 30 limits at national level, but Zurich has already gone ahead and installed 30 km/h limits both day and night on 400 km of roads (out of a total of 750 km).
The main benefits
• The actual speed measured on roads with the new 30 limit has fallen by 15 km/h.
• Thanks to this drop in speeds, noise pollution has reduced by 2.4 dB(A) during the day and by up to 4.5 dB(A) at night – half the level before the speed limit was introduced.
• On top of this new-found calm, the 30 limit has brought with it a clear improvement in road safety.
• A survey of residents found that the 30 limit had been well received by all affected groups (including traders and public transport users). Pedestrians and cyclists were the most satisfied. Many of the interviewees felt that the roads were safer and less noisy.