Two blocks of Stockton Street, between Geary and Ellis, are now closed to traffic. It's all in preparation for the eventual construction of the Union Square subway station.
"The work we have to do that closes this street is Union Square station and we are going to start on that early next year," SFMTA spokesperson Paul Rose said.
Traffic is being rerouted; some of it onto Grant Street, which became a two-way street over the weekend. Muni buses have been rerouted since the utility relocation project began. And the closure is going to be long-term -- for five years.
Eventually the subway will run from Caltrain at 4th Street, across Market past Union Square, all the way to Chinatown.
"This will cause some disruption," Rose said. "But we're trying to work with the merchants and people driving in the area to make sure this is as painless as possible."
"We're living in a construction zone, you just do the best you can," said Karen Flood, the new executive director of the Union Square Business Improvement District, which represents the majority of retailers. "We have been working with the central subway team to notify merchants up and down Stockton of the changes."
Flood says the project will impact businesses, but Union Square is still getting heavy foot traffic. And the MTA says subway riders will increase from 40,000 to 60,000 a day. Many, they say, could come to shop.
"Our motto down here is short term pain, long term gain," Flood said. "So we see the long term benefits certainly of the central subway."
"We feel we've put together a plan that minimizes the pain and inconvenience for people that are driving in the area," Rose said. "The reroutes in effect for transit are getting people to their destination. It's just on a different route."
Officials do note, however, that residents and tourists will get a break every year between Thanksgiving and New Year's. The street will open up to accommodate holiday shoppers.
The subway is expected to open in 2019.