Caltrans is set to shut down portions of Highway 1, also known as 19th Avenue, in San Francisco three separate times this spring for repaving work.

The extended weekend closures along the busy thoroughfare are scheduled to begin in late April and wrap up in late May.

Here’s what to know about the closures, work timeline and detour information.

When will Highway 1 (19th Avenue) in San Francisco be closed? What part of Highway 1 (19th Avenue) will be impacted?

Caltrans provided the following details for the three extended weekend closures:

First closure: 7 a.m. Friday, April 24, until 5 a.m. Monday, April 27 / Northbound Highway 1 (19th Avenue) from Sloat Boulevard to Lincoln Way

Second closure: 7 a.m. Friday, May 8, until 5 a.m. Monday, May 11 / Southbound Highway 1 (19th Avenue) from Lincoln Way to Sloat Boulevard

Third closure: 7 a.m. Friday, May 22, until 10 a.m. Monday, May 25 / Southbound/northbound Highway 1 (19th Avenue) from Sloat Boulevard to Holloway Avenue

For all three closures, two lanes will be shut down and one lane will remain open. Motorists are encouraged to use alternate routes.

Detours during the Highway 1 (19th Avenue) closures in San Francisco

Caltrans provided the following detour instructions for Junipero Serra Boulevard for the April 24-27 closure:

Steer right to Junipero Serra Boulevard

Take a left on Sloat Boulevard

Take a right on Sunset Boulevard

Take a right on Lincoln Way

Take a left on 25th Avenue

Take a right on Martin Luther King Jr. Drive

Take a left on Highway 1 (19th Avenue)

Caltrans provided the following detour instructions for Brotherhood Way for the April 24-27 closure:

Drive westbound on Brotherhood Way

Take a right on Lake Merced Boulevard

Take a right on Sunset Boulevard

Take a right on Lincoln Way

Take a left on 25th Avenue

Take a right on Martin Luther King Jr. Drive

Take a left on Highway 1 (19th Avenue)

Why is Caltrans shutting down Highway 1 (19th Avenue) in San Francisco?

Caltrans said it needs to repave lanes of Highway 1 (19th Avenue) in order to remove potholes and repair unsound pavement.

“This work will improve ride quality, and maintain safe and connected travel route,” a statement on the Caltrans website reads. “Furthermore, residents and motorists have voiced their concerns about this road and have requested it be rehabilitated for some time. Caltrans heard the public’s call, and we’re responding.”

Visit the Caltrans website for more information on the Highway 1 (19th Avenue) rehabilitation project.