It would be easy to get frustrated ahead of time with the traffic fallout from the work slated for the next several months on and around the Tobin Bridge.

The state work at the Chelsea Curves (a name no one recognized before last week, but a location familiar to regular commuters) is expected to cost more than $215 million and take two years to complete. And no matter the somewhat rosy predictions of state engineers, we know this: It will make a bad traffic situation much worse.

But let’s also be clear: This is work that needs to be done, for the safety of commuters and the future viability of the bridge as a structure and a way into and out of Boston. The two-mile-long truss bridge -- the longest in New England -- is almost 70 years old and is considered by the state to be “structurally deficient.” 

In rolling out news of the project, state officials pointed to corroded beams and gaps in the decking of the bridge and viaduct, which were last overhauled in the ‘70s. Not doing the work is to invite calamity.

“I’ve actually had a little bit of fear and stress sitting in traffic over that bridge and these weird thoughts go into your mind and you hear about crazy disasters and stuff,” Chelsea commuter Michael Chapman told NBC Channel 10. “We don’t want the bridge to collapse, that’s for sure. So whatever they need to do they could do it.”

The project kicked off Monday night, when Route 1 northbound on the Chelsea side of the bridge narrowed from three lanes to two. Two lanes will remain open during the day. At night, the thruway will be reduced to a single lane, after most of the workday commuters have made it home, but before North Shore and Merrimack Valley Red Sox fans head home from a night at Fenway.

Then, in about a month, Chelsea Curves -- the elevated, arcing part of Route 1 in Chelsea just before the Tobin begins its path over the Mystic River -- will be cut from three lanes to two in both directions during the day, and to one lane at night. The lane restrictions will be in place until the work is done in 2021.

What will be the effect on traffic for the 63,000 or so commuters who use the roadway every day? Think of a garden hose kinked in the middle.

“To be clear,” state Highway Administrator Jonathan Gulliver said last week in a masterpiece of understatement, “these lane closures will lead to increased congestion and travel times, especially during the first few weeks.”

State Rep. Tom Walsh, who travels regularly to the Statehouse from the North Shore, was somewhat less circumspect.

“I think we are in for some pain if you are a commuter to Boston,” the Peabody Democrat told reporter Ethan Forman last week.

Gulliver and other state officials have urged commuters to consider other options for getting in and out of the city. There’s Interstate Route 93, of course, the Callahan and Sumner tunnels and the commuter rail. There are also several bus routes that run from Boston to points north and back, but we are hard-pressed to understand how that will speed up the commute for people who need to get to and from work.

This will also be a test of MBTA and its promise of improved service. State officials are urging commuters to park in out-of-town spots such as Beverly, Salem, Haverhill and Newburyport and take the train into town. They have also added service to the Blue Line subway. Here’s hoping it goes better than Monday, when a disabled train on the Red Line meant delays of more than 40 minutes in Cambridge.

The best bet, it seems, will be patience. Give yourself extra time to get to and from the city. If you can take public transportation, take it. Don’t take your frustrations out on your fellow drivers, like the two ladies from Beverly and Gloucester who got into a nationally televised fist-fight on the side of Route 128 in Danvers last Friday. And keep in mind the only other option would be not to fix the bridge, which is no option at all.