LIE shut down westbound at Exit 48

A serious early-morning accident involving a tractor trailer and at least one other vehicle has closed down all westbound lanes on the Long Island Expressway between Exit 48 and Exit 46 in Melville and Plainview Friday — and police said there is a good chance the road will remain closed through the morning rush hour.

Nassau County police said there were “serious injuries” in the crash, but could not immediately say how many vehicles had been involved or how many people had been injured.

The crash occurred not far from where the horrific fatal tanker crash took place on the eastbound roadway in January. The westbound road was closed at 3:41 a.m., according to the New York State Department of Transportation.

All westbound traffic is being diverted onto the service road, creating a traffic snarl backing up for miles.

More than a dozen police cars and emergency vehicles were at the scene before dawn Friday, with both Nassau police and the Suffolk County Sheriff’s Department involved.

Traffic on Route 110, which already has traffic slowdowns due to an on-going construction project in the area, was also congested with spillover volume from the expressway.

Exit 48 is Round Swamp Road, while Exit 46 is the exit for Sunnyside Boulevard.

Police said an accident investigation figures to keep the road closed at least through rush hour — but possibly through most of the morning.

The accident comes on the heels of another commuting nightmare for LIRR riders after last night's storm blew through the region.

The Port Washington branch remained suspended Friday morning, according to the MTA website.

LIRR spokesman Joe Calderone was advising commuters on the Port Washington line to use other branches.