It is the Forbidden Road, only for trucks, but under a proposed pilot plan all drivers would be able to use it to help relieve the growing congestion in the Seaport District.
State transportation officials will file a notice in February with Massachusetts environmental regulators to allow cars coming into South Boston to use the Bypass Road, which is currently restricted to trucks and other commercial vehicles. The pilot program would last six months and could begin as soon as March.
Frank DePaola, the acting state transportation secretary, said he hopes the test period will show that cars and trucks can share the road because commuters and commercial drivers have different rush hours. “There is really no overlap,” said DePaola.
The 1.1-mile road was built to accommodate trucks during the construction of the Central Artery, and when the tunnels were done, the road remained restricted. But as traffic becomes heavier in the fast-growing Seaport District, there has been pressure to open up the road to everyone.
To lift the restriction on passenger vehicles, the state must show that an open road won’t add air pollution to the area, and if it does, officials will need to find ways to offset the harm to the environment such as increased bus service or carpooling.
As part of its filing, the state will also propose letting all drivers use the high-occupancy vehicle lanes outside of South Station and the South End.
The state decided to try a pilot program after traffic data showed allowing more drivers on the Bypass Road would not clog it. Last winter, everyone could drive on the road when the Callahan Tunnel was closed three months for repairs. It soon became a popular shortcut for those going eastbound into the South Boston Waterfront, carrying an average of 6,100 vehicles daily, or almost triple the number than when it was restricted.
Still, it felt like an empty country road because it was built to handle many more commercial vehicles.
Tom Glynn, who runs the Massachusetts Port Authority, has concerns about the impact on the companies that ferry goods in and out of the marine industrial area. That is why he pushed for a six-month trial before making any permanent changes.
“If you are in the trucking business, time is literally money,” Glynn said. “Their business and competitiveness depends on doing things efficiently.”
Warren Dibble, president of Boston Marine Park Business Association, said truck drivers aren’t convinced the change will be good. They do not mind more cars on the road, but if it results in traffic jams, that might force truck drivers to take alternative routes.
“Truckers typically seek the path of least resistance,” said Dibble, the chief financial officer at Harpoon Brewery, which produces most of its beer at its South Boston headquarters. “If there is a backup — these trucks could go into neighborhood roads.”