As you might have noticed, an Interstate 80 off-ramp currently runs through San Francisco’s Transbay Block 8, the site for a 550-foot residential tower to rise (click designs to enlarge).

In order to increase the size of the Block 8 parcel for the development of up to 740 housing units, the Folsom Street off-ramp will be reconfigured, converting the diagonal off-ramp into a straight off-ramp that ends at Fremont Street with construction slated to start in August 2014:

The existing Interstate 80 off-ramp splits into two different legs, directing traffic in two directions. The northbound Fremont Street leg enables vehicles to travel towards downtown San Francisco and has approximately four times the peak hour traffic as the Folsom Street leg.

[T]he realigned Folsom Street off-ramp will mirror the Fremont Street leg with a touchdown at 90 degrees with the intersection and a tight inside turning radius of 30’. When completed, the intersection will be signalized to allow pedestrians to perpendicularly cross the off-ramps on the west side of Fremont Street. The design of the new traffic signal will be prioritized for off-ramp traffic by remaining in the “green” phase, except when a pedestrian needs to cross.

The Folsom Street off-ramp realignment is scheduled to be finished by February 2015.

15 thoughts on “San Francisco’s Folsom Street Off-Ramp And Fremont Street Redesign”
  1. Given the amount of traffic on First Street during rush hour, it will be fun getting into and out of that building by car.

  2. When this relatively new off-ramp was being configured, Caltrans had the option to build it straight the first time around and chose not to.
    Makes me wonder who is picking up the bill, them or the developer.

  3. There is a huge amount of traffic using the Harrison and Fremont Street offramps during rush hour. They are both needed to handle the volume. Eliminating one of them would cause backups and safety problems on the Bay Bridge.

  4. From the Caltrans web site for ramp volumes, the Fremont off-ramp carried an average of 27,500 vehicles per day in 2012 and the 5th Street/Harrison off-ramp carried 19,700. So to answer your question sf – no, Harrison is not sufficient.
    Regarding the configuration of the off-ramp, I can’t remember any of the details but I think the existing configuration (with the curve) was implemented as a temporary solution to traffic handling during the seismic reconstruction of the west approach to the Bay Bridge. At one point during reconstruction, the Fremont off-ramp from the left lane of the bridge was shut down and reconstructed so the off-ramp from the right lanes needed additional capacity. The curve was never intended to be permanent.

  5. I was not referring to the 5th st. offramp but the Left exit Harrison/ Fremont exit located alongside Fremont. But it is probably true that the single lane ramp is not sufficient. Weird how it was designed.. they both exit to basically the same location, Harrison st. exits to Harrison and Fremont and the Folsom exit to Folsom and Fremont.

  6. The two exits to essentially the same place make sense when you consider that the upper deck of the Bay Bridge carried traffic in both directions when it first opened (until 1963), so the left exit was originally an eastbound on ramp.
    Regarding the Folsom/Fremont off ramp, it originally ended at First Street. At some point it was extended above First to Fremont.

  7. The existing configuration was a “gift” to Rose Pak who, along with her Chinatown merchant constituents, was concerned that tearing down the Embarcadero Freeway would mean people couldn’t find Chinatown and would kill business. In all the public hearings, SPUR was the only party that testified against the foolish idea that curving the offramp into Folsom would help “find” Chinatown, when in fact all it would do is truncate an important development parcel. It was portrayed in those hearings as permanent. Who is paying for the redo? You and me, the taxpayers.

  8. Jim, given Peej’s comment about the date of the reconfiguration (2005), do you have any documentation supporting your claim? The Embarcadero Freeway was demo’d in 1989.

  9. I don’t keep my professional papers going back that far, but if you look up the EIR/EIS on the rebuild (probably titled something like the “I-280 Transfer Study Implementation”) you will find testimony and letters from SPUR. You could also search the Chronicle for commentary by Rose Pak and the Chinese Chamber of Commerce, which was highly reported at the time.
    I believe the Embarcadero demolition began in the spring of 2001 and the rebuild was programmed to take 6 years in toto, so the 2005 date for this segment would make sense.

  10. I make the left from Folsom onto Fremont 5 days a week, and can tell you the change is a minor one that should not affect traffic but will greatly free up dead space at the intersection.
    When I saw that the parcel was going to be developed I was wondering if the off ramp was going to be reworked, and happy to hear it will be.
    But that said in the prior posting about the 550 ft building that was approved it also showed an image of a 350 ft building at Howard and 2nd where a parking lot currently exists (across from the 26 story building currently being built). ,,, Anyone know about this ?

  11. City_Dweller said: “There is a huge amount of traffic using the Harrison and Fremont Street offramps during rush hour. They are both needed to handle the volume. Eliminating one of them would cause backups and safety problems on the Bay Bridge.”
    Um, when is there NOT a traffic backup on the Bay Bridge? 🙂

  12. According to a changeable message sign on the off-ramp this morning, the project will start on September 23rd with the closure of the Folsom Street ramp. Seven-month construction period.

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