WHITE RIVER JUNCTION — Faster trains are about to start running along the Connecticut River, south of White River Junction, following an upgrade.

Starting Monday, trains traveling south of the community to the Massachusetts border will be running as fast as 79 mph, about 20 miles faster than the current speed limit.

Officials warn that drivers and pedestrians will have less time to react to oncoming trains at railroad crossing with the increase in speed in southern Vermont.

Windsor Police Chief Stephen Soares said there are at least three crossings in Windsor with lights to warn of upcoming trains, but he guessed that there are numerous private crossings that don’t have any warning signals.

“My personal observations of trains traveling through Windsor have actually caused me some concerns, but nothing like the heightened state of concern I would have if a train came anywhere near Windsor at 79 mph,” he said.

The speed limit for Amtrak’s “Vermonter” traveling between White River Junction and St. Albans, which is just north of Burlington, also will increase, from 55 mph to 59 mph.

The speed increase was made possible by improvements to 220 miles of New England Central Railroad track funded in 2010 by a $50 million federal stimulus grant. Rail beds, bridges and tracks were upgraded for passenger and freight trains.

Upgrades were made at 46 rail crossings on public roadways but many non-gated crossing are on private roads, said Trini Brassard, an assistant director for the Vermont Agency of Transportation. VTrans had to add lights and gates to every public crossing south of White River Junction.