Business associations in French speaking Switzerland are backing the CHF 6bn plan to widen the A1 autoroute.
Voters will make the final decision in November.
Many different associations point out the A1 was designed for 20,000 cars a day - now carries 90,000.
The Vaud Chamber of Commerce say there were 40,000 hours of traffic jams across the country in 2022 and this impacts trade.
But that doesn’t mean they're against an expansion of the rail network. Vincent Subilia from the Geneva Chamber of Commerce says it’s entirely possible to do both.