Caltrans is undertaking a major project on the 101 freeway in San Francisco this July, and the agency is holding a series of public meetings to discuss how it may impact businesses, traffic, and more.

Starting on July 7 and running through the rest of the month, Caltrans is planning to shut down lanes of the "Alemany Deck" — a viaduct section of U.S. 101 that runs between the 280 interchange/Alemany Boulevard and Industrial Street. This piece of roadway is aging and in need of replacement, and what this means is at least three weeks of headaches that will include a detour off the freeway for northbound drivers.

As Caltrans explains, this 800-foot freeway bridge dates to 1950, and the concrete bridge deck needs to be replaced while "the column and foundation are in satisfactory condition." Replacing the decks will make for both a smoother ride for commuters, and a "higher chance that the freeway is operable during a major earthquake."

Demolition can't begin until Caltrans installs a two-ramp, two-lane detour that will take northbound vehicles off the freeway at Alemany and then back on again at the end of the construction zone. On the southbound side, traffic will be reduced to two lanes and speeds down to 35 miles per hour — meaning that traffic backups will come in both directions almost immediately, and last most of the day.

Map via Caltrans

Here's the Caltrans plan in full:

Before demolition can occur on the US-101 northbound decks, traffic will be detoured to a 2 lane offramp and onramp at Alemany exit. The northbound US-101 Alemany exit will be closed 3 days in advance and eastbound Alemany Blvd will be closed to through traffic so that the project off and onramp detour can be constructed. The existing westbound Alemany Blvd will be converted to a 2 way street to also accommodate east bound traffic. Once the northbound detour is in effect, the decks will be demolished and reconstructed within approximately 9 days. Once northbound decks are completed, the southbound US-101 traffic will be crossed over to the newly constructed northbound deck while the southbound deck is being demolished and reconstructed in approximately another 9 days. It is likely a total of approximately 18 days that this project will affect regional traffic. Local Alemany Blvd will be restored as soon as possible.

Area residents and businesspeople are already skeptical. As Lydia Patubo, Manager of the nearby Flowercraft Garden Center, tells ABC 7, "I'm not so sure... nothing ever starts on time or finishes on time." She also says that the nursery is likely to "lose a lot of business" because of the chaos on Alemany that will result.

Eileen Maxey, who makes her living on the road, tells the station that this project will surely "add a considerable amount to my already long commute everyday."

The first public meeting about the project was Wednesday night, but there's another tonight (Thursday) from 6 to 8 p.m. at Willie Brown Jr. Middle School at 2055 Silver Avenue; and another on Saturday, February 22 from 1 to 3 p.m. at Bernal Heights Neighborhood Center at 515 Cortland Avenue.