Thomas Tinlin, acting commissioner of the Boston Transportation Department, tells GlobeSt.com that permits restricting the delivery of construction materials from 9 p.m. until 5 a.m. have been issued for a handful of projects being built along the Rose Fitzgerald Kennedy Greenway, and on North Washington and Cambridge streets. Permits are no longer being granted for trucks and vehicles to park outside designated work areas in those locations, he said.

"We just want to make sure we're moving vehicles in a safe manner and protecting pedestrians," says Tinlin, noting that the permits are only for those areas affected by the tunnel collapse. Other areas of the city have not been affected. "The whole notion that the city is shut down is just not the case," he says.

The city's decision to issue restricted permits is a result of efforts to keep main thoroughfares open while investigators continue their probe into the structural safety of tunnels constructed as part of Boston's 15-year highway relocation project known as the Big Dig.

Tinlin says his department is also working closely with state highway officials on a reconstruction project on Cambridge Street near the Storrow Drive exit. A schedule to allow off-hour deliveries to that construction site is being worked out, he says.

It was unclear how many projects were impacted by the restricted permits or when full delivery of construction materials would be allowed to resume, Tinlin notes. The Massachusetts Turnpike Authority was also reviewing construction areas impacted by the tunnel closure and has not allowed any construction work in the affected area that would cause traffic tie ups.