The California Transportation Commission on Wednesday approved $82 million to replace the parallel spans of Highway 101 over the Petaluma River.

The construction work, which could start this fall and take two years, is a major part of the widening of Highway 101 through Sonoma County and the Novato Narrows.

The Sonoma County Transportation Authority also also applied for $32.4 million to replace the Highway 101 bridges over Highway 116.

Sonoma County is well along on its effort to widen Highway 101 from Windsor to the Marin County line, at a cost of $950 million.

It still would need $145 million to widen the freeway from Petaluma Boulevard North to the Marin County line, completing the widening project.

-- Bob Norberg

If You Go

On Thursday, SMART will offer round-trip public preview rides between its Rohnert Park and Marin Civic Center stations. Trains will depart southbound from SMART’s Rohnert Park Station at 8 and 10 a.m.; noon and 2 p.m. Northbound trains will depart from Marin Civic Center at 4, 6 and 8 p.m.

A SMART train aimed at providing service to the Marin County Fair will run Saturday and on July 4. That train will leave the Sonoma County Airport Station both days at 5 p.m. and arrive at the Marin Civic Center Station at
6:01 p.m.

Departures for July 1 and 4 are as follows:

5 p.m. depart Sonoma County Airport Station
5:07 p.m. Santa Rosa North Station
5:12 p.m. Santa Rosa Downtown Station
5:19 p.m. Rohnert Park Station
5:23 p.m. Cotati Station
5:36 p.m. Petaluma Downtown Station
5:47 p.m. Novato San Marin
5:55 p.m. Novato Hamilton
6:01 p.m. arrival at Marin Civic Station

Return trips from Marin Civic Center on both days take place after the fireworks celebration at 10:36 p.m. People can get on and off at any station. Departure times for the trip back to Sonoma County are as follows:

10:36 p.m. depart from Marin Civic Center Station
10:42 p.m. Novato Hamilton Station
10:50 p.m. Novato San Marin Station
11:01 p.m. Petaluma Downtown Station
11:14 p.m. Cotati Station
11:18 p.m. Rohnert Park Station
11:25 p.m. Santa Rosa Downtown Station
11:30 p.m. Santa Rosa North Station
11:37 p.m. arrival Sonoma County Airport Station

For more information about the preview rides, visit www.SonomaMarinTrain.org.