MassLive.com reports, “Those who have made it this far without the Massachusetts Department of Transportation’s favorite gadget — the E-ZPass transponder — are running out of time [to] take advantage of an incentive. . . .” MassDOT announced that a “grace period” will end on May 8 during which it has allowed legacy pay-by-plate customers who convert to E-ZPass to pay outstanding bills at the discounted transponder toll rate.