Authorities are urging motorists to steer clear of the area where Route 18 and Route 1 meet in Middlesex County this weekend, with lane and ramp closures throughout.

The closures are to accomodate the replacement of the Route 18 bridge over Route 1.

Beginning at 8 p.m. Friday and continuing until 5 a.m. Monday, NJDOT contractor Anselmi & DeCicco will close the two left lanes of Route 18 northbound and one lane of Route 18 southbound for the demolition and reconstruction of the bridge approaches on the left side of Route 18 northbound, the DOT said.

One lane of Route 18 northbound traffic will be diverted onto the Route 18 southbound bridge using a movable barrier system.

Two lanes of traffic will be maintained in each direction on Route 18 throughout the weekend except for Saturday from midnight to 7 a.m, when a third lane on Route 18 northbound will be closed. One lane of Route 18 northbound will remain open overnight on Saturday.

This is the fourth and final weekend closure related to the reconstruction of the Route 18 bridge approaches, according to the DOT.

The scheduled ramp closures and detours for this weekend are as follows:

Route 1 southbound to Route 18 southbound Detour:
The ramp from Route 1 southbound to Route 18 southbound, and the Route 18 southbound right and center lanes will be closed from 8 p.m. Friday to 5 a.m. Monday.

Motorists traveling on Route 1 southbound to Route 18 southbound will be directed to continue on Route 1 southbound and exit at the Ryders Lane interchange to Route 1 northbound to Route 18 southbound.

Route 18 northbound to Route 1 southbound Detour:
The Route 18 northbound ramp to Route 1 southbound will be closed from 10 p.m. Friday to 10 a.m. Saturday and from 10 p.m. Saturday to 10 a.m. Sunday.

Motorists traveling from Route 18 northbound to Route 1 southbound will be directed to Route 1 northbound and exit at the Woodbridge Avenue interchange to Route 1 southbound.

Route 1 northbound to Route 18 northbound Detour:
The Route 1 northbound ramp to Route 18 northbound will be closed from 9 p.m. Friday to 5 a.m. Monday.

Motorists traveling from Route 18 northbound to Route 1 northbound will be directed to the Woodbridge Avenue interchange to Route 1 southbound to Route 18 northbound.