In a reversal from the traffic pattern on recent nights, the California Department of Transportation plans to close all lanes on Southbound U.S. Highway 101 Ventura Freeway starting at 11 p.m. Tuesday, May 21, for construction of the Wallis Annenberg Wildlife Crossing in Agoura Hills, a project being constructed by Santa Clarita-based C.A. Rasmussen.

Monday night’s closure was the final nightly closure of all lanes on northbound Highway 101 for crews to place large girders over the freeway to construct the crossing.

Tuesday night’s closure is for crews to remove the large crane which placed a total of 82 girders above the freeway, starting over the southbound lanes and then moving to the northbound lanes. This event marks the successful completion of the girder placement work and the end of a nightly full closure of all freeway lanes in one direction at a time.

During the full freeway closure Tuesday night on Southbound Highway 101:

– All lanes on Southbound Highway 101 will be closed at Chesebro Road beginning at 11 p.m.

– Southbound lanes will reopen for traffic by 4 a.m.

– Northbound lanes will stay open all night.

– All southbound traffic will exit the freeway at Chesebro Road and will use a local street detour: South on Chesebro Road, east on Agoura Road, and north on Liberty Canyon Road to the Southbound 101 on-ramp.

– To avoid delays on Highway 101 and the local detour, all freeway motorists are strongly advised to bypass the construction area by using the following all-freeway detour: North on State Route 23 to eastbound State Route 118 to southbound I-405 in the San Fernando Valley.

– The full freeway closure will begin at 11 p.m. but some lanes may begin closing (a partial freeway closure) as early as 7 or 8 p.m.

The Wallis Annenberg Wildlife Crossing will reconnect natural habitat that is vital for wildlife to survive and thrive in Southern California. It will be the largest wildlife crossing of its kind. The project has a target date for completion in early 2026. Construction started in 2022.

Caltrans will provide additional construction and traffic information on the social media platform X, formerly Twitter, at @CaltransDist7. Those without an X (Twitter) account can view all the information at twitter.com/CaltransDist7.

Information also is available at the Caltrans web site and at 101wildlifecrossing.org

The public can sign up for free weekly email updates about the wildlife crossing’s construction and closures by sending an email to D7inquiries@dot.ca.gov or calling (213) 897-9372.

Caltrans advises motorists, before starting their travel, to check current highway closures at Caltrans’ QuickMap service at Quickmap.dot.ca.gov or by using the free app for digital devices.

Caltrans reminds drivers to “Be Work Zone Alert” and “Slow for the Cone Zone.” Traffic fines are doubled in construction zones.