The long-awaited new exit off Interstate 95 into the N-Squared Innovation Corridor along the Needham-Needham border is now open. A new series of ramps, interchange 19, opened Aug. 19. The exit allows direct access from I-95 onto Kendrick Street to head into Needham Crossing and the Wells Avenue office park in Newton. It also allows drivers on Kendrick Street to get directly onto I-95 southbound. “Employers and employees have been waiting a long time for this,’’ said Greg Reibman, president of the Newton-Needham Regional Chamber, “and it is going to greatly enhance our efforts to bring new businesses and jobs to this region.” The changes, part of the 128 Add-a-Lane project, should by the end of 2018 be connected by collector and distributor roads that are expected to reduce congestion.Ellen Ishkanian can be reached at email@example.com.