1927 Swiss referendum

A double referendum was held in Switzerland on 15 May 1927.^[1] Voters were asked whether they approved of amending article 30 of the constitution and a federal law on car and bicycle traffic.^[1] The constitutional amendment was approved by voters, whilst the traffic law was rejected.^[1]

The constitutional question was a mandatory referendum,^[1] which required a double majority; a majority of the popular vote and majority of the cantons.^[2] The decision of each canton was based on the vote in that canton.^[2] Full cantons counted as one vote, whilst half cantons counted as half.^[2] The traffic law question was an optional referendum,^[1] and required only a majority of voters.^[2]