California’s deferred maintenance backlog for streets and highways had already topped $135 billion before fierce winter storms flooded roads and undermined bridges, adding $600 million to the toll.

“The transportation system is in bad shape,” Will Kempton, a retired Caltrans director, told the Los Angeles Times recently. “We have just underinvested in our transportation infrastructure for decades, and it’s coming home to roost. Particularly after the recent storms, our roads are in very, very bad shape.”

So when will state leaders stop dithering and start fixing roads?

There may finally be reason for a little optimism.

Gov. Jerry Brown and the Democratic leaders of the state Senate and Assembly have set an April 6 deadline to complete work on a funding plan that would generate as much as $60 billion over the next 10 years for highway and road repairs.

Senate Bill 1, which comes up today for its second committee hearing, would raise excise taxes on gasoline and diesel fuel for the first time in two decades. SB 1 also would increase the vehicle registration fee by $38 and impose a $100 a year fee on electric vehicles to help pay for their contribution to wear-and-tear on California roads. A similar measure has been introduced in the Assembly, and Brown offered a plan of his own with slightly smaller tax increases and a $65 a year “road improvement charge” for all vehicles.

An average motorist would pay an extra $9 to $13 a month depending on mileage, fuel efficiency and which plan ultimately is adopted. That’s a small price for a big investment in the state’s transportation network.

The source of California’s highway troubles is no secret: Low gas prices and increased fuel-efficiency have eroded excise tax revenue while inflation has driven up the cost of road repairs. As a result, transportation officials are postponing desperately needed maintenance projects and putting off expansion of congested roads.

SB 1 wouldn’t cover all the state’s needs, so Brown is seeking $100 billion from President Donald Trump’s proposed $1 trillion infrastructure program. In Sonoma County, voters probably will be asked to extend Measure M, a quarter-cent sales tax approved in 2004, to complete the widening of Highway 101 through Petaluma and to provide money for local street repairs.

Road work traditionally has been funded by user fees, primarily fuel taxes, but they haven’t kept pace with needs — in California and across the country. Similar problems plague flood control systems, as illustrated by the near disaster at the Oroville Dam.

Elected officials have ignored the problem for too long. Republicans, leery of raising any taxes, refused to provide the necessary votes to act during a special legislative session that lasted most of 2015 and 2016. Democrats gained a two-thirds majority in November’s election, giving them the votes to deliver on a solution for one of California’s longest-standing and most economically threatening problems.

They should act before their self-imposed April 6 deadline to begin filling California’s infrastructure sinkhole.

Editor's note: This editorial has been updated to reflect that Sonoma County's Measure M is a quarter-cent sales tax.