Drivers with a Massachusetts-issued E-ZPass transponder will pay the same or less in tolls on nearly two-thirds of trips when all-electronic tolling begins later this month, under new rates approved Thursday.
The rates are largely unchanged from those recommended in late August, with a few exceptions, transportation officials said. Drivers will pay a bit less at gantries — overhead structures that automatically charge tolls — on the Massachusetts Turnpike in Weston and Allston, and a bit more at one in Newton.
The new rates go into effect Oct. 28 on the entire length of the turnpike, the Tobin Bridge, and in the Sumner, Callahan and Ted Williams tunnels.
Under the initially proposed rates, drivers would have paid higher tolls for about nearly half of all trips, officials estimated. Now, tolls will be the same or less for about 64 percent of trips.
Officials said they adjusted the rates after drivers raised concerns at public hearings. Drivers going through the Weston tolls, for instance, were initially asked to pay “a higher toll rate than one could argue was fair,” said Thomas J. Tinlin, the state's highway administrator.
That could have caused some drivers to avoid the turnpike altogether, increasing traffic on alternate routes like Route 9, officials said.
Under the new rates, drivers will pay 20 cents in Weston, rather than the proposed 45 cents.
The marker in Allston will charge 35 cents, down from a proposed 50 cents. To balance out that change, drivers will pay 35 cents in Newton, an increase from a proposed 20 cents.
All told, the changes will cost the state about $7 million in annual toll revenue, officials estimated. But the state will save several million dollars a year with the switch to all-electronic tolling and another $20 million annually starting in 2017, when bonds for the western portion of the turnpike are expected to be paid off.
The new system will feature 16 gantries, replacing 26 toll plazas. Drivers will no longer need to slow down to pay tolls, which officials say will reduce congestion, pollution, and accidents.
Officials project the new system will save drivers more than 280,000 hours and as much as 875,000 gallons of gasoline a year, while reducing greenhouse gas emissions by up to 7,800 tons annually.
The new rates will be higher for drivers with transponders issued by other states. Drivers without transponders — whose license plate numbers will be captured on cameras so they can be billed by mail — would pay the highest tolls to cover the cost of processing the transactions.
Officials also announced Thursday that the state will offer a six-month grace period for drivers who do not use transponders to sign up for the E-ZPass program and receive a credit on their account that reflects the extra amount they were billed by mail.
Matt Rocheleau can be reached at email@example.com. Follow him on Twitter @mrochele