Switzerland: 30 km/h on main roads now needs proof it will not cause unwanted diversion of traffic

An amendment to Switzerland's federal road signs ordinance took effect on 1 October 2026. Authorities seeking a 30 km/h limit on a main road must now show, in the expert report already required to justify such a limit, that it will not cause unwanted diversion of traffic onto residential streets. Tempo 30 zones on residential streets are unaffected. The Federal Council adopted the change in August to implement a parliamentary motion. The transport department also plans to amend its own ordinance so that priority from the right is generally not allowed on 30 km/h main roads, with no date set.

The design is an evidence gate, not a ban. Local authorities keep the power to lower limits but carry the burden of proof that the change will not move the problem elsewhere. The open questions are how strictly the diversion test is applied, and whether it slows the spread of lower limits on main roads or simply documents it.