Campaigners against the proposed widening of several autoroute sections have launched their campaign ahead of the vote later this month.
The federal government has given the go ahead to six major projects, including the widening of the A1 between Geneva and Nyon to three lanes in each direction.
While the hope is the project would cut traffic jams, those against the idea say simply bigger roads will attract more cars.
It will cost CHF 5bn.
It’s not just environmentalists that are opposed. Many local communes along the route say it would be better to invest in public transport instead.