The significance of Tuesday’s vote to preserve California’s new gas-tax hike was not lost on Gov. Jerry Brown.

“This is bridges, and girders, and overpasses, and cement, and concrete — this is real stuff,” he said during an election night speech, referring to the $5.2 billion stream that the tax hike generates annually to fix roads and keep mass transit running.

That money would have evaporated if voters had passed Proposition 6, a ballot initiative to repeal the taxes and fees that state lawmakers enacted last year as Senate Bill 1. After a hard-fought and at times acrimonious campaign, Prop. 6 went down with 55 percent of voters opposed and 45 percent in favor.

State and county officials had already directed the first batch of SB1 revenue toward 6,500 infrastructure projects, said Caltrans spokesman Matt Rocco. They include 400 retrofits of state highways, such as the continuous carpool lanes under construction on the Marin-Sonoma Narrows, which will eventually thread from Windsor to the Robin Williams Tunnel. SB1 also is paying to repave most of Interstate 880 in the East Bay.

If the repeal had passed, hundreds of construction projects might have been frozen in place.

A new report from the Mineta Transportation Institute, “The Future of California Transportation Revenue,” predicted that by 2020, California will collect $10.4 billion from SB1 — the gasoline tax increase of 12 cents per gallon and diesel fuel tax increase of 20 cents per gallon, along with other vehicle fees.

Lawmakers had last raised the gas tax in the 1990s, and the money it supplied before SB1 wasn’t enough to prevent highways from deteriorating and keep commerce rolling in the fifth largest economy in the world.

The effects of Prop. 6 would have been severe in the Bay Area, which already has the worst roads in the country according to a recent analysis by the Washington, D.C., transportation research firm TRIP. Rural counties would have been hit even harder. Rugged northern areas such as Trinity County — which is nestled along the Trinity River and flanked by the Salmon and Klamath Mountains — would have lost funding to plow snow in winter and clear a path for emergency vehicles, or to cut back brush and trees so they don’t ignite forest fires.

Even so, voting maps provided by the secretary of state showed that residents of rural areas — including Trinity — supported the repeal. Its defeat came from the more populous coastal counties.

Rachel Swan is a San Francisco Chronicle staff writer. Email: rswan@sfchronicle.com Twitter: @rachelswan

10 projects that are moving forward because of the money spared from Prop. 6 1. Marin-Sonoma: $6.1 million to widen striping along Highway 101 from the Sonoma/Mendocino counties line to the San Francisco C ounty line. Currently under construction. 2. Muni repairs: $9.5 million for the San Francisco Municipal Transportation Agency to address its maintenance backlog for buses, street cars and light rail. 3. San Francisco bridges: $1 million to revamp four bridges on Highway 101 in San Francisco. Under construction. 4. Alameda-Contra Costa counties traffic management: $40.4 million to install ramp meters, ramp carpool bypass lanes and traffic operation systems along Interstate 680 from Scott Creek Road in Fremont to A l costa Boulevard in San Ramon . 5. Longer electrified Caltrains: $164.5 million to expand new electric trains to seven cars, provide W i- F i onboard and increase bicycle parking at stations. 6. San Francisco roads: $23 million to repave 39 miles of road across the city. 7. Oakland potholes: $7 million to hire 20 street maintenance workers, who will help repave 20 miles of potholed streets. 8. BART to Silicon Valley: $730 million to extend train service into San Jose and Santa Clara. 9. East Oakland Bus Rapid Transit: $15 million (pending approval) for AC Transit buses to zip along a 9.5-mile strip of International Boulevard, from Uptown Oakland to the San Leandro border. 10. Butte County communication cable: $11.6 million to install 9.4 miles of cable for a system that supplies transportation updates to travelers on Highway 99 from Estates Drive to Garner Lane near Chico.