Replacement of the aged railroad bridge over the Connecticut River between Old Saybrook and Old Lyme will start next year with the exact same purpose as the last one, in 1907: Get the trains across a wide estuary of tidal marshes and flowing river.

But today’s builders have to be humbler than the men who constructed the old bridge with their Gilded Age frame of mind. Those builders did not have today’s scientific knowledge. They had never heard the phrase “climate change.” When the railroad magnates of the turn of that century built, they did so with the aim of progress, progress and progress; it was an unfettered way to make a fortune.

Today we aim to adapt, adapt and adapt. But that, too, is progress.

The $827 million bridge project officially got its funding package together last month as part of a $2 billion grant for 10 projects in the state, using money from the bipartisan infrastructure law. The project will allow trains to speed up by nearly a half hour between New York City and Boston, encouraging drivers to substitute easier, electrified travel for the fossil fuels they’d be burning on I-95, the Headache Highway. Routes and rail beds are intended to take into account rising water levels in adjacent Long Island Sound.

Contractors for the project can expect vigilance from environmental groups watching out for the effects on habitats and creatures because the riskiest time for plants and animals is during construction. For several years, heavy equipment will need access to the site, and while barges and construction platforms will likely support the work in the river, trucks and excavators will be working both shores.

It takes room for a dump truck to turn around, and the most tempting ways to create the space may be to knock down trees or offload a pile of fill, 1900s style. Contractors in the 21st century know enough, however, to pause and look for the least possible harm to terrain, waterways and woods.

The whole project is on, in and around salt marshes, which are key to managing rising sea levels and preventing loss of seabird and sea creature species. Past railroad builders didn’t care and probably didn’t even know what losses of marshland could mean, but ignorance is no longer an option. Projects such as past work done at Barn Island in Stonington serve as reminders that the scars of construction can be permanent.

If managed with care, however, the building of the bridge is great news for shoreline Connecticut. The bridge will cross the river south of the existing structure. The Northeast Corridor, Amtrak’s busiest, will still include the traditional route linking New York to Boston through New Haven and Providence, but more speedily.

Previous planning had leaned toward bypassing the shore-side route for high-speed upgrades, instead concentrating on the inland route through Hartford and Worcester. The New Haven to Providence stretch would have had to settle for a study that might or might not have recommended even limited commuter rail. The most truly terrible idea was a tunnel under the river between Old Saybrook and Old Lyme that would have cut through the Florence Griswold Museum.

Who at the Federal Railway Administration ever thought that idea would fly? The FRA ultimately responded to pressure from the public and elected officials to think again.

It was news last week when Gov. Ned Lamont lost a skirmish in his effort to do like California, New York and New Jersey by curtailing gasoline-powered vehicles on Connecticut roads. Lamont agreed with the governors of the neighboring states that the goals would be to end sales of new gas-powered vehicles by 2035 but legislators reviewing the proposal came up with sound questions that need to be answered or risk setting up another unreachable goal. The governor stepped back for now, but lawmakers have indicated they still want to work on a better version of the plan.

A safer, sounder Northeast Corridor bridge over the Connecticut River makes an excellent companion piece for reaching the overall goal of reduced carbon emissions. By 2107, when this bridge is about halfway through its estimated lifespan, Connecticut roads and rails will all have different capacities and will be used by different modes of transportation because they must. The question is when, not if. It’s good to be getting started.

Lisa McGinley is a member of The Day Editorial Board.