After decades of delays, funding to upgrade the Needham Street and Highland Avenue corridor has been approved.

The decision by the Boston Region Metropolitan Planning Organization on July 30 means funds for the $14 million renovation project will be available for construction starting in 2018.

“Businesses and residents have been waiting decades for a solution to the traffic nightmares along Needham Street and Highland Ave.,” said Greg Reibman, president of the Newton-Needham Chamber. “We’re grateful to the MPO, our State House delegation and our municipal leaders for making this happen.”

The project would stretch roughly two miles, from Webster Street in Needham to Route 9 in Newton. It would widen sidewalks, improve intersections, add bikes lanes and crossing signals and rehabilitate the bridge over the Charles River.

“Our success in securing these funds for the N2 Innovation Corridor district at Needham Street and Highland Avenue is another example of how cities, towns, and private sector partners working together can more effectively advocate for the resources needed to finance projects that will benefit residents and businesses alike,” Mayor Setti Warren said. “The transportation and infrastructure improvements we will bring about as a result of our work together will bolster economic development by making the area more attractive to businesses and their employees.”

Last year, Newton and Needham received a $3.3 million state MassWorks grant for Needham to begin work between First and Second avenues and for Newton to reconfigure the intersection around Oak and Christina streets. Both of these developments have reduced the cost of the rest of the project.

State Rep. Denise Garlick credited the “strong consistent advocacy at each level of decision making” from municipal officials along with the two communities’ State House delegation for finally securing the funds.

“I also commend the Chamber and the committed representatives of the local businesses for their advocacy,” Garlick said. “The next few years of infrastructure work in the N2 corridor and the Add-A-Lane project will be challenging. I look forward to working with the whole team on the field.”

The Boston MPO is the regional body that oversees federal and state transportation spending, including the region’s share of the federal gasoline tax. Needham Street and Highland Ave. are state roads, but would be turned over to the municipalities at the conclusion of the project.

Although money for the construction has been secured, the final design process, which is being overseen by the Mass Department of Transportation, as well as permitting and some land taking needs to be completed.