The state Senate approved a bipartisan transportation plan, co-sponsored by Sen. Joe Fain, R-Auburn, on Monday with a 27-22 vote.

The plan invests more than $15 billion to maintain and build transportation infrastructure and is based on a series of reforms that protect taxpayers and make projects less expensive, Fain said.

“This plan will help get people to work, put people to work and make the department of transportation work better,” said Fain, who serves as vice chair of the Senate Transportation Committee, in a media release. “South King County and our entire state continue to grow. More people and more jobs mean increased demands from drivers, transit riders, pedestrians and bicyclists.”

South King County would see the long-awaited completion of State Route 509 and Highway 167 at a cost of $1.8 billion, reducing congestion and dramatically improving the ability to move freight to both major ports from manufacturing centers.

Much of the funding comes through an 11.7 cent increase in the state gas tax that would be phased in over three years.

Other congestion-relief projects in South King County would include widening of Interstate 405 from Renton to Bellevue and upgrades to the interchange of I-5 and State Route 18 in Federal Way.

Kent would also see the grade separation of South 228th Street over the Union Pacific railroad tracks at a cost of $15 million, significantly reducing area congestion due to increasing train traffic.

“This is also important to our local community, giving cities the opportunity to meet their own individual needs like creating safe routes to schools,” said Fain, whose district includes parts of Kent.

Reforms to current practices were essential to the overall transportation package so that as people pay more they can expect better use of their tax dollars, according to Fain.

Right now the state pays sales tax on highway projects, redirecting gas tax funding away from transportation projects. The Senate approved a bill removing the transportation sales tax, reducing overall costs.

The transportation package next goes to the House of Representatives for its consideration.