State highway crews have started work on a nearly $45 million project near Lake Grove aimed at improving safety and traffic by adding an extra lane and more traffic signals along Route 347.

The project is the seventh phase of ongoing work over the past 15 years to modernize 12 miles of Route 347 between Routes 25A and 454.

It will add a third lane from Hallock to Nicolls roads on Route 347 to increase the flow of traffic. The speed limit will be reduced to 45 mph and new enhanced traffic signals and crosswalks will be added to one of Long Island’s most dangerous intersections for pedestrians.

From 2014 to 2023, there were 586 crashes at the intersection, including 13 serious-injury crashes and one fatality, according to state transportation data compiled as part of Newsday’s Dangerous

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