“Hacking” traffic signals in the City

sf traffic light

Driving so many hours in the City offers a lot of time for thinking, especially thinking about driving.

I put a lot of thought toward the question: How can I reach a destination most quickly?

The answer is rather complicated, much more so than it may appear at first glance. It’s not just about distance. It’s about traffic. It’s about roadway capacities. It’s about speed limits. But, often the most important factor is traffic signal timing.

When I drive between midnight and the morning rush, which starts around 5 am, there is virtually no traffic. Or, to be more specific, traffic congestion is beneath a threshold such that all traffic signals in the City will completely clear within one signal cycle.

It is during this phase between midnight and the morning rush where you can explore the naked signal cycles with the traffic variable removed. It is great fun.

I start to develop intuitive (implicitly memorized) and non-intuitive (explicitly memorized routes) maps of signal timing, especially on frequently used routes. And, soon, I began to develop traffic signal ‘hacks’, ways to slip through long strings of intersections.

The first ‘hack’ I found is when I’m driving south on 8th St to get to the 6th St 280 on-ramp. Heading south on 8th St, most people would turn left at Bryant to get to 6th St for the 280 on-ramp. But, you’ll get stuck on at least one light (7th/Bryant) and maybe another (6th/Bryant). Instead, while you’re on 8th St as soon as Harrison turns green, gun it and pass through Bryant. You’ll just barely make the green to make a left on Brannan, head through a green that turns at just the right time at 7th/Brannan and hit another green to make a right on 6th. (Just watch out for the Highway Patrol station at 8th/Bryant.)

[EDIT 6/10/08: This doesn’t seem to work anymore. The light at 8th at Folsom stays red longer now, making it impossible to reach a green light at 8th and Brannan unless you had a Ferrari and floored it.]

My friend Steve showed me a nice ‘hack’ to get on 101 from Gough. If you’re heading South on Gough, most people take Fell to Octavia to the 101 on-ramp. But, during the morning rush you can bypass a signal cycle or two if you continue on Gough past Fell and instead take a right on Haight which is the last street from which you can turn onto Octavia and the 101 onramp, bypassing a few blocks of heavy traffic.

Signal knowledge combined with estimates of traffic congestion make the acquired knowledge of City taxi drivers rather valuable. Which calls into question this story I found about F1 driver Michael Schumacher taking the wheel of a taxi in Deustchland to make a flight on time. It may work between these small villages where speed is the primary factor. But, it would never work in the City where the key to the fastest time between point A and point B is not pure acceleration, but instead requires an intimate knowledge of signal timing and traffic congestion.

Do you have any other City signal hacks?

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5 Responses to “Hacking” traffic signals in the City

  1. who_the says:

    Here’s three I think you’ll like (plus one I hate):

    * Make a right at Florida from southbound Cesar Chavez (then a left on Precita) to bypass the red light at Cesar Chavez @ Bryant;

    * If you want to make a left on Van Ness from eastbound Mission but have missed the light, make a right onto South Van Ness at the corner of Mission & Van Ness, then a quick U-turn back onto Van Ness at the cutout to make a left onto 12th Street. You’ll almost always bypass what can be an interminable red;

    * If you want to make a left from northbound Masonic onto Geary, check for a red light before the previous signal light at Anza. If the Geary light is red, but the Anza light is green, make a left on Anza, go down three blocks, make a right on Blake, and then a left on Geary. There’s no light at Blake and you’ll miss two lights on Geary at Masonic and then Collins;

    * Be careful of Golden Gate Avenue after hours. Things go great until you get to Gough; after that, you’re almost certain to miss three long lights at Franklin, Van Ness, and then at Polk. This troubles me because Golden Gate is a favorite route of mine when the lights don’t trap you.

  2. kfarr says:

    @who_the: These are great!

    I’ll try these out next time I’m on the road.

    Another one to add to the ‘hate’ list:
    – Franklin from Market to California is great after hours, but Franklin north of California is timed to an excruciating 10 miles an hour in the wee hours of the morning. I don’t get it. Did the Pac Height/Cow Hollow lobby get DPT to change the timing for their neighborhood only?

  3. Reena Saini says:

    i want to download traffic signal hackingsoftware

  4. fias says:

    i want to download traffic signal hackingsoftware

  5. pratosh yadav says:

    i also want to download traffic signal hacking software.

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