The southbound Interstate 5 off-ramp at Calgrove Boulevard in Santa Clarita will be closed on most nights through the end of May, effective immediately, according to a notice today from Caltrans.

During construction of a $171 million repaving project now underway on I-5, the southbound off-ramp at Calgrove Boulevard generally will be closed as follows, subject to change:

On most Mondays through Fridays, the ramp will close by approximately 8 p.m. each night and reopen by 6 a.m. the next morning, except on Saturday mornings when it will reopen by 8 a.m.

On many Saturday and Sunday nights, the ramp will close by approximately 7 p.m. and reopen by 9 a.m. on Sundays and by 6 a.m. on Mondays.

Select weekends will require extended closures of the ramp, starting as early as 3 p.m. Saturday and ending by 10 a.m. Sunday.

The schedule is subject to change and weather-permitting. Other I-5 on ramps and off ramps will close intermittently in and near Santa Clarita during construction. Signs will be posted to notify drivers in advance of ramp and lane closures.

When the southbound Calgrove Boulevard off-ramp is closed, drivers can exit I-5 at the previous southbound off-ramp at Lyons Avenue or at the next southbound off-ramp at Balboa Boulevard-San Fernando Road.

The Caltrans I-5 Roadway Rehabilitation Project is replacing and repairing concrete lanes on nearly 16 miles of I-5 (Golden State Freeway), from south of State Route 14 (Antelope Valley Freeway) to north of Lake Hughes Road.

Construction is expected to be completed in the summer of 2019. Most of the work is being done at night, requiring some freeway lanes to be closed between 9 p.m. and 5 a.m.

Drivers are urged to allow extra travel time and use caution in the construction area. Lower speed limits are posted and traffic fines are doubled in construction areas. The California Highway Patrol is on duty.

Guy F. Atkinson Construction is the contractor on the project, which is being built with state and federal funding.

Information about the I-5 Roadway Rehabilitation Project in North Los Angeles County/Santa Clarita is available online and on Twitter @CaltransDist7.