SAN FRANCISCO — Friday will not a be a good day for Marin commuters going to San Francisco as they will encounter a completely closed Doyle Drive.

The section of roadway just south of the Golden Gate Bridge will close from 10 p.m. Thursday to 5 a.m. Monday. During that time Doyle drivers will see a new northbound viaduct come online.

But there will be traffic pain before that gain.

“Stay away if you can, it will be a mess,” said Molly Graham, project spokeswoman. “It’s the first time we will have a closure during a commute day.”

The Golden Gate Bridge to Highway 1 — Park Presidio in San Francisco — will remain open during the closure, but major delays are expected.

Work will continue for 79 hours straight during the closure when crews will labor to connect and transfer traffic lanes to the new permanent roadway, which includes the new Main Post Tunnels, northbound Battery Tunnel, northbound high viaduct and restored connections to Highway 1/Park Presidio.

Golden Gate Ferry service will increase during the closure, while the agency’s bus service will be trimmed during the period.

A tour of Doyle Drive on Tuesday revealed the roads tunnels Marin drivers will use to get into and out of San Francisco beginning Monday are just about complete, but awaiting some intensive work over the weekend.

“It’s looking good and we are excited to be at this point,” said Ron Richardson, chief engineer for San Francisco-based Golden Link Concessionaire, which was selected to design, build, finance, operate and maintain the project for 30 years. “This will be, as it was before, but a lot safer.”

Materials to complete the work will be stockpiled on site, and a temporary concrete plant will be running, with other materials delivered via truck throughout the weekend.

The new roadways will have wider lanes and safety shoulders, which didn’t exist on the old Doyle Drive and will be completely separated. Pylons were used to separate traffic on the old Doyle Drive and many head-on collisions occurred over the years.

The old “seismically challenged” structure was built in 1936 and had been given a safety score of 2 out of 100 in a state rating system, reflecting its poor condition. Part of it was pulled down during a two-day weekend closure in April 2012; another section of the old Doyle Drive was demolished in 2013.

That work allowed the existing viaduct to open. The new second viaduct has gone in where the old northbound Doyle Drive once stood.

Drivers now use five lanes and one tunnel to go northbound and southbound on the existing viaduct. Traffic on the viaduct — the southern approach to the Golden Gate Bridge — and in the new Battery Tunnel is separated by a movable median barrier.

When finished Monday, three lanes will flow northbound and four southbound with the movable median barrier gone. There will also be a new interchange in the Marina.

Late 2015 had been the target date for completion, but a good pace of construction and a lack of rain have helped push up the date.

During the closure some work will occur on Highway 101 near the Golden Gate Bridge Toll Plaza where the span’s movable median barrier will be lengthened about 900 feet. On the north end of the span Sausalito on and off ramps will be adjusted and the barrier will be lengthened 100 feet.

Visitor parking lots at the Golden Gate Bridge will be shut down during the project from 8 p.m. Thursday through 5 a.m. Monday.

People attempting to park will be turned away.