The Skagit River bridge on the I-5 will open on Wednesday with a temporary span replacing the collapsed section, Washington State Governor Jay Inslee announced on Tuesday.

The bridge, which connects Vancouver and Seattle along Interstate 5 collapsed on May 23 after a truck carrying a wide load struck part of the structure. Three cars ended up in the river, but nobody was seriously injured in the incident.

Traffic will be limited to 40 mph starting on the approaches to the bridge, according to the Washington Department of Transportation Secretary Lynn Peterson.

"Roughly 99 per cent of the car and truck traffic will be able to cross the I-5 bridge again," said Peterson.

The replacement span is slightly narrower than the original bridge, with each direction of the temporary span reduced from two 12-foot lanes with 3-foot shoulders, to two 11-foot lanes with one-foot shoulders. 

It will be open to all legal loads, but all oversized or overweight trucks will still have to use the detour route.

The state says a US$6.7 million contract has been signed to build a permanent fix for the bridge. Installation of the permanent span is expect to close the bridge again for two weeks in October.