Railroad tracks that were idle for nearly 50 years will start carrying locomotives going 60 miles per hour from before dawn to 11 at night.
On the 18 miles of track on the Greenbush line from Braintree to Scituate, trains will cross 28 streets at grade level.
With all that in mind, the Massachusetts Bay Transportation Authority has undertaken a major safety campaign in recent months. The agency has conducted programs in area schools, held open forums, and run training for local public safety personnel.
This week, the T planned to distribute 750,000 fliers alerting people to the arrival of the trains. Despite these efforts, officials say that the dangers presented by the trains - which can take nearly a mile to stop when traveling at top speed - are very real.
Robert Murphy, the T's manager of safety training, said it is up to residents to heed warnings.
"We try to get the message out there and hope they hear it," he said.
Each year averages 11 accidents and two deaths on train tracks on the MBTA system, according to Edward O'Brien, a retired T official who works for the rail safety program Operation Lifesaver. The other two branches of the Old Colony Railroad, which opened in 1997, have experienced a number of incidents.
In 1998, a 15-year-old girl was killed in Abington as she was maneuvering her bicycle around lowered safety gates. Two years ago, the driver of a pickup truck was killed in Abington when he apparently tried to go around a gate.
Nationwide, the number of deaths on railroad tracks has held steady at about 400 annually for the past 35 years despite major improvements in the design of railroad crossings.
While incidents at crossings are down, trespassing has been a growing problem across the country. Train tracks are often in secluded areas that attract thrill seekers, underage drinkers, and people looking for a shortcut. Public safety officials have issued stern warnings about trespassing on Greenbush line property.
"You have to make it clear to children and people in the community: Being on the tracks is not all right," said Joseph O'Connor, lieutenant commander for the T's transit police. "It's illegal. You can be arrested."
Stephen Jones, the MBTA's director of railroad operations, said trespassing is difficult to stop.
"There is nothing that will keep the kids off the track," Jones said. "There is fencing along the right of way and there is education, but nothing will keep them off."
To minimize noise in the area, train engineers will not sound their whistles routinely at crossings, although they will do so if they see people or vehicles on or near the tracks. The towns on the line requested the no-whistle policy.
Five of the crossings have what are known as four-quadrant gates, which block all access to the tracks and prevent motorists from going around a closed gate. The special crossings have pavement sensors that prompt a gate arm to lift to allow a vehicle trapped on the tracks to exit.
When a train approaches a crossing, alarms will sound and lights flash. Seven to 10 seconds later, according to the T's procedures, the gates will come down, and 20 to 30 seconds after that, the train will pass.
T officials say closing and opening a gate for a train crossing takes about a minute. School buses, oil trucks, and vehicles carrying hazardous cargo are required to stop at all crossings. A sometimes-overlooked safety problem at crossings is the rear-ending of vehicles that trailing drivers do not expect to stop.
The T last week rejected calls by some officials and residents to delay the scheduled opening of the train service on Halloween to the next day. T officials said the trains have already been making trial runs and trick-or-treaters in the area should not be a problem.
MBTA officials say they are confident Greenbush will be a safe operation.
"We've been doing it a long time," Richard Murphy, chief train dispatcher for the commuter rail service, told residents at a recent information session at Scituate High School. "We've been doing it safely. We'll make sure the train provides good safe transportation through your towns."
Robert Preer can be reached at email@example.com.