Drivers familiar with the traffic nightmare on Van Ness Avenue due to recent construction should note traffic lanes will shift to the median starting Thursday.

As part of the Van Ness Improvement Project, construction crews will create two work areas to replace sewer, water main and emergency fighting water systems from the 1800s.

The $316.4 million project will not only replace major water utility infrastructure, but will also create San Francisco’s first bus rapid transit system, dedicating the center lanes for Muni and Golden Transit buses only.

According to the San Francisco Municipal Transportation Agency, which is overseeing the project, southbound traffic will be first shifted to the median on Thursday, followed by northbound traffic on Nov. 13:

“Once the lanes shift, on some blocks of Van Ness Avenue, two lanes traveling in the same direction will separate to pass on either side of median islands where 12 trees are protected for construction.”

Crews will work on the western side of Van Ness Avenue between Sutter and McAllister streets, and on the eastern side of Van Ness Avenue between Jackson and Lombard streets.

The SFMTA said the work will at times require reducing traffic on Van Ness Avenue to just one lane in each direction.

Currently, the project faces a nearly six-month delay, SFMTA officials said during an update to the San Francisco County Transportation Authority two weeks ago.

Project manager Peter Gabancho said the cause of the delay came from the primary contractor, Walsh Construction, which took longer than expected during a bidding process for the utility work.

Walsh Construction has countered, blaming the SFMTA for delays, and is now seeking compensation. The claim is now in the dispute-resolution process, according to transit officials.

Work to replace to the water infrastructure beneath Van Ness Avenue will last through the winter of 2019, the SFMTA said.

The entire Van Ness Improvement Project is set to open in the summer of 2020.