Along with the bridge closures and detour signs that fill the Massachusetts cities of Somerville and Medford, there are signs of progress on the MBTA's Green Line extension project.
Long debated and delayed, the $2.3 billion project is now full speed ahead with a deadline of late 2021.
"It feels a long way away on the calendar, but it is not a long way away at all. It's right here," program manager John Dalton said.
NBC10 Boston got a behind the scenes tour of some of the construction sites Wednesday. The 4.7 mile stretch will feature seven new stations, including one at the now-closed Washington Street bridge in Somerville and another in Ball Square, where the Broadway Street bridge is closed for a year.
"The ultimate benefit will far outweigh the current inconveniences," Dalton said.
Part of the project will bring the tracks closer to some properties, which is why the construction also involves installing noise barriers. Some of the barriers have already started going up along backyards on Walnut Street in Somerville.
Roughly 400 workers are on site doing the job, and Dalton said more will start soon. They were busy digging and installing massive columns that will support the elevated viaduct of the extension Wednesday afternoon.
One of the challenges of building the new tracks right next to existing railroad tracks is that every time a train comes, crews have to stop until it passes. Dalton said it can happen every 20 minutes during rush hour, but they are working around the clock to finish.
For now, the inconveniences are far from over. The Medford Street bridge will close soon, and the Lechmere train station in Cambridge will shut down later next year while it is rebuilt on the other side of McGrath Highway.
Even with all of the disruptions, Dalton believes it will be worth the wait.
"At the end of the day, the Green line is being built to get people out of their cars and to lessen traffic. That's the whole point," Dalton said. "So yeah, there is traffic now, but at the end of the day, when this thing is in service, it will be better for all of us."