A rendering of what the 405 Freeway will look like at Wilshire Boulevard. The I-405 Sepulveda Pass Improvements Project began demolishing the first of eight ramps joining Wilshire and the 405 Freeway on Friday. Reconstruction of all eight Wilshire ramps is expected to take more than one year.

What You Need To Know About The Ongoing 405 Freeway Wilshire Ramp Closures:

Plan ahead, adjust your travel times, and share the ride — that’s the message from the Los Angeles County Metropolitan Transportation Authority.

The 405 Freeway Wilshire ramp closures started at 10 p.m. Friday night. Construction of the westbound and northbound on and off-ramps from Wilshire is expected to take 90 days.

Reconstruction of all eight Wilshire ramps is expected to take more than one year.

These closures and the subsequent reconstruction of the other six Wilshire ramps are expected to create significant temporary impacts to Wilshire Boulevard and adjoining streets, such as Federal Avenue, Sepulveda Boulevard and Veteran Avenue. Sunset Boulevard and Santa Monica are recommended alternatives.

Building the new ramps will reduce the conflict between Wilshire Boulevard and the I-405 as it crosses Wilshire Boulevard. In turn, this should reduce backup at other north/south streets, such as Westwood Boulevard and Veteran Boulevard.

Below is a detailed schedule of upcoming work and the resulting detours for the “ramp-jam” blockades.

Saturday, June 23: Day Shift

No closures; remove wood from inside bridge and pull support of excavation beams; drill holes for support of excavation.

Saturday, June 23: Night Shift

Place protective soil on Sepulveda Boulevard; demolish westbound Wilshire on-ramp to northbound I-405 and northbound I-405 off-ramp to westbound Wilshire; remove soil and clean roadway.

— Full closure of Sepulveda, from Wilshire to Montana, 10 p.m. to 11 a.m.

— Two lanes closed in each direction on Wilshire, from Veteran to Federal, 10 p.m. to 11 a.m.

— All northbound on- and off-ramps closed from 10 p.m. to 11 a.m.

Sunday, June 24: Day Shift

Finish excavation and pulling beams; no closures.

Sunday, June 24: Night Shift

Demolish bridge abutments and footings; set up to drive pile

— Full closure of Sepulveda, from Wilshire to Montana, 9 p.m. to 6 a.m.

— Two lanes closed in each direction on Wilshire, Veteran to Federal, 9pm to 6am.

— All northbound on and off-ramps closed 9 p.m. to 6 a.m.

Monday and Tuesday, June 25-26: Day Shift

Start driving pile; no closures.