SFMTA: Market Street Traffic Pilot is Meeting Its Objectives

IMG_2212.jpgThe Market Street traffic diversion pilot only got better for people on bikes when the SFMTA striped bright green bike lanes. Not all drivers are complying with the required turns, though. Photo: Michael Rhodes

It appears the San Francisco Municipal Transportation Agency has come to similar conclusions to Streetsblog’s in its review of the pilot traffic changes on Market Street at 6th and 10th Streets: A big thumbs-up for transit, bike riders, and people on foot, relatively minor impacts on traffic, and some uneven results when it comes to driver compliance with the new configuration.

Judging from a brief update [PDF] on the program produced Friday, the "Required Right Turns on Eastbound Market Street" pilot appears to be meeting the SFMTA’s goals on most fronts. Traffic volumes on eastbound Market just east of 10th Street declined by roughly 200 vehicles per hour during rush hour.

Most of that traffic diverted to Mission Street, where it slowed down transit vehicle travel times by three percent — but that’s offset by a five-percent increase in transit travel times on Market. Muni noted in an earlier report that vehicles are traveling down Market an average of 50 seconds faster.

People on bicycles and taxi drivers are continuing to respond well to the changes, and most drivers are at least complying with the required turns at 10th Street (no word from the SFMTA on whether they’re grateful for being diverted from hectic Market Street.) As Streetsblog reported last week, the vast majority of drivers are behaving well at 10th Street, but 6th Street, which has much less clear signage for drivers about the required turn, has lower compliance, the report concludes.


For now, the traffic treatments that make 10th Street easier for drivers to understand (or harder for them to ignore) aren’t possible at 6th Street, since, as the report notes, the roadway is narrower and there’s a Muni boarding island. That means no separate lane for bikes, which helps avoid a bottleneck as drivers queue up to turn right. There are also heavier pedestrian volumes at 6th Street, making it harder for drivers to turn right, with the resulting line of right-turners creating some issues for those on bike.

The original objectives of the eight-month-old pilot program, the report states, are to "determine whether diverting private vehicle traffic improves transit reliability, pedestrian safety and bicycling comfort," "observe impact of diversion on [the] surrounding street network and determine whether any problems would be created on the streets that experienced increased traffic volumes," and "decrease use of Market Street as a private vehicle through route."

So has it been a success? The report concludes it has been, and has met its objectives "without any adverse changes to traffic conditions." The city is now gathering additional data for "environmental clearance to make the restrictions permanent if so desired."

  • When I went down Market around 12:30 yesterday, I saw nearly 90% of cars continue straight at 6th street. When I approached the intersection, I just told every driver to turn right as I passed them (sorry JohnB, talking to drivers again). I don’t think any of them did, but I took the lane and rode at a relaxed pace the rest of the way to 3rd. I also had a couple private autos fly by me in the taxi/bus only lane.

    I recommend just putting huge DO NOT ENTER signs at 6th with the obvious exemption note for bikes/taxis/MUNI. The signage for required turning is horrible.

  • Why not created a separated, green bike lane from the far side of the Market and sixth intersection to the mid-block delivery vehicle turnout, eliminating the curbside lane so that there is no auto lane to continue forward into? And put up some decent signs, of course

  • Nick

    The local news segment of “People Behaving Badly” focused on how drivers endanger cyclists on Market Street last night. It’s only one minute long… you have to see the dumb driver at Octavia. Wow.

    http://www.kron.com/News/FeaturedReporters/StanleyRobertsPeopleBehavingBadly/tabid/215/Default.aspx

  • Janelle P.

    I ride market everyday on my bike and this is the first time I have heard that vehicles are required to turn right on 6th street. Then the signage is really bad at that intersection. That definately needs to be improved.

  • The report Nick linked points out the power of “groupthink” and social norms in driving behavior. If one driver goes straight around the sign, there’s no reason everyone else won’t think they can too. Sadly, something that should be as clear-cut as driving rules are too often guided more by what people see others doing. In this case, it results in not just single cars violating the signage, but whole traffic cycles of cars.

    My god, just enforce it and ticket them already! I’ll say it again: justifiable goldmine.

    P.S. At least that driver in the bike lane at Octavia didn’t make the right turn!

  • Btw, shouldn’t the traffic diverted onto Mission theoretically not slow bus travel times at all since it has a dedicated BUS ONLY lane? Oh, right, that lane’s a joke…

  • @Aaron, I never knew that there was one lane bus only on Mission til now. If you wouldn’t have said anything, I would continue to believe that the solid two rows of traffic were suppose to be there. But I’m sure the cars NEED that lane.

    And just to add the obvious statement, ALL bus only lanes in this city are jokes. Cars rule the day.

  • I agree with mikesonn, 6th needs a DO NOT ENTER (Buses, bikes and taxis excluded) sign. Maybe even 3.

  • Now for SFMTA and the Mayor to step up and lower the speed limit in SOMA from 35 MPH to 25 MPH to help improve pedestrian safety as they divert 200 cars into SOMA every hour … Oh, wait … No press conference opportunities come along with improving pedestrian safety by lowering speed limits downtown? How silly of me to think this Mayor would bother without some media attention available.

  • jamie, I’m with you 100%, but they should also come thru and get rid of ALL the one way streets. 4 lanes all flowing the same direction with those long blocks will only continue the perception that 45 mph is safe even if you make the speed limit 25 mph.

  • Moley

    Various studies have been done on speed limits and safety. Paradoxically, it has been shown that limits that are too slow actually increase congestion and accidents.

    Back in the day, the freeway limits of 55 mph caused a lot of problems.

    In SOMA, there are lights at every intersection and so pedestrians should all be crossing at green walk lights, where the traffic is halted. It’s not clear to me how the speed limit alters that.

    SOMA blocks are long and a higher speed limits is justified there while, for instacne, it would not be north of Market.

  • NBP

    The bus lanes on Mission St are rush hour only. However that doesn’t stop drivers from flouting that rule, regardless of the time of day.

  • Yeah, usually when I’m passing it is on the 30/45 going up 4th around 5:15 pm.

  • If I had my druthers, we’d have Stop signs mid-block and four-way stops at the major intersections … then again, I’m rooting for a congestion charge too. 🙂 Am I losing my Detroit/GM Family cred or what?!?

  • Moley – can you direct us to any evidence from those studies? I have a looooot of trouble believing that, especially considering all the time spent sitting at red lights reduces any actual travel time benefits while increasing danger. And congestion isn’t really the problem in San Francisco – on the freeways, yes – but on the streets, the problem is speed and danger from cars.

    Also, I didn’t really understand your point about pedestrian crossings in SOMA, or what you were addressing with that.

  • I’m guessing that Moley’s study might be this one — http://www.dot.state.oh.us/districts/D01/PlanningPrograms/trafficstudies/SpeedZones/Documents/2hj01!.pdf — which studied the effects of speed limit changes on rural highways and saw an increase in crashes at 14 sites where speed limits were lowered and a decrease at 41 sites where the limits were raised, but cautioned that the data might be meaningless because of the small sample size. Even if the sample is meaningful, it would still be surprising if research on rural speed limits was directly applicable to city traffic.

  • Moley

    Aaron/Eric

    It was a long time ago I read a couple of studies and can’t cite them there. But they made sense when I read them. You could probably google the subject as well as I could.

    But the essence of the reasoning given was twofold.

    The 55mph freeway speed limit was introduced to save gas not save lives. The problem was that it causes “bunching” – all traffic was now traveling at near exactly the same speed. The result was that shunts became more common.

    When the 55mph limit was repealed (because the price of gas fell), the accident rate actually decreased.

    It also helped that cars had become much more powerful and safer. 40 years ago, 70mph was a near top speed for most cars. Now it is a comfortable cruising speed. 80 is the new 60.

    Caveat: I didn’t factor bikes into this reasoning.

    The congestion argument is simpler. Clearly a higher speed gets more traffic through any given point. Slow it down and there are more vehicles on any given block. Consider the extreme case – if the speed limit were 5 mph we would have permanent gridlock.

    Finally, my point about pedestrians was that the speed limit does not affect their ability to cross safely, as long as there is a stop light at every intersection and pedestrians don’t try and jaywalk the middle of the block. As a pedestrian in the city myself, I have more problems with cars in the narrower, smaller blocks than in SOMA.

  • Moley –

    I did a quick Google search about the 65 mph speed limit. Couldn’t find anything about a decrease in deaths/accidents, but everything I can find is about an increase, namely referring to a study I read a while ago. Here’s one article: http://www.autoblog.com/2009/07/20/study-raising-national-speed-limit-has-resulted-in-12-500-death/2

    It’s unfortunate you can’t cite your supposed study – such wild claims certainly need it.

    “The problem was that it causes “bunching” – all traffic was now traveling at near exactly the same speed.”

    This is ridiculous. You’re talking as if somehow people robotically obeyed the 55 mph limit and not the 65 mph limit. This is far from the truth, and largely the reason that it was increased to 65 mph.

    “Clearly a higher speed gets more traffic through any given point. Slow it down and there are more vehicles on any given block.”

    That could only be true insofar as the speed limit actually keeps traffic so slow that it doesn’t have to wait at stop lights (which would be a wonderful increase in both safety and efficiency). But that isn’t reality. The reality is that most traffic is racing unnecessarily fast to sit at the next red light.

    “My point about pedestrians was that the speed limit does not affect their ability to cross safely.”

    Yes it does. It increases the chances of accidents with pedestrians, and the likelihood of more severe accidents. Faster traffic has a lot more trouble seeing and stopping for peds (and everything else) in time, and is more likely to be careless at intersections (particularly when making turns). Higher speed limits also increase drivers’ incentive to run red lights and push yellows. And finally, they go hand-in-hand with higher volumes of traffic, inherently increasing the overall likelihood of accidents (with peds suffering the most).

  • One more point about this:

    “Clearly a higher speed gets more traffic through any given point. Slow it down and there are more vehicles on any given block.”

    If you’re going to use the “bunching” argument, traffic lights cause it more than any speed limit will. Another benefit of having a speed limit at or lower than traffic lights allow is that they reduce bunching and spread traffic out more.

  • Karl

    On the required right turn.
    It does not seem like a lot of thought has been spent on that concept.
    Of course drivers will ignore it, because if they follow, they end up at yet another right turn or head towards the freeway. Going opposite to where they need or want to go. This will have to improve.

  • Moley

    Aaron,

    The point with the “bunching” theory was that if the limit is high, people drive at whatever speed they like i.e. there is a varaition of driver speeds.

    But with a 55mph limit, which is slower than almost every driver drives on the freeway, then it means that everyone drives at around 55mph, causing “bunching” and a whole lot of rear-end shunts.

    As for urban congestion, what if cars traveled at 1mph? Would there be wide open blocks with no traffic? Doesn’t seem likely.

    The issue with pedestrian safety that you cite isn’t to do with speeds but with adherence to red lights. If cars obey red lights, it doesnt matter what the speed limit is.

  • Moley, in SOMA cars travel near highway speed so when they see a yellow they speed up more, most of the time flying thru a red light at over 10 mph over the speed limit. In dense areas, i.e. North Beach, cars traveling at slower speeds tend to slow and then stop when they approach yellows. Speed limit does matter. Why set people up to fail?

    And the bunching makes no sense. Rural roads (i.e. 55 mph) will bunch because they tend to be two lane roads where highways at 65 mph tend to be multi-lane affairs that offer chances to pass slower cars.

    And who is saying that cars should travel at 1mph? Stop setting up straw men to knock down.

  • Moley

    Mike

    If the limit at 55 is so low that everyone drives at that speed, then there is no opportunity to pass because all lanes are moving at the same slow speed. At least that is the theory I heard; I wasn’t around at the time.

    And the 1 mph was a “reductio ad absurdum” argument to make the point that there is an optimum speed to get traffic on its way – neither too fast nor too slow.

    Finally, I wasn’t advocating that pedestrians leap into the crosswalk as soon as they their light but rather letting any residual traffic pass and then safely cross while the traffic waits. That would happen regardless of the limit.

  • You can’t site a study you can’t find or don’t really recall reading. And what changes from 55 mph to 65 mph that all of a sudden people decide they might vary their speeds from the norm slightly? That just makes no sense what so ever.

    Increased speed limits lead to increased occurrence of running yellow/red lights. Why would someone slow from 45 when going 55 will get them thru the light? Also, it is much easier to slow for an upcoming yellow/red if you are driving 25 mph.

  • I meant “cite” obviously. But Moley you are commenting on non-existent studies and putting your own libertarian views into the constitution. If you want to have a discussion, please come to the table a bit more informed.

  • Honestly I think he’s just pulling stuff out of his ass.

  • Rhonda

    I find that new green bike lane, going east, crossing Van Ness Avenue to be very dangerous. The bicyclist is on the right side of the road, in the bike lane, just before crossing Van Ness. As well, there are cars on the left side of the cyclist, going full speed. Once you cross Van Ness, the bike lane moves into the middle of the street, forcing the bicyclist to cross in front of fast moving cars in order to get into that green patch of a bike lane. I do not do it! I’m not a skilled enough rider to cross in front of that speeding traffic just so I can be in this joke of a green bike lane. Because of that, I stay in the right turn lane marked for the cars, riding in the middle of that lane, only then am I able to move into the green bike patch of a lane. The way it is laid out there, heading east, crossing Van Ness to the bike lane there is very, very dangerous.

  • Riding up Market yesterday my wife and I were riding among cars once again. We even had several tail us pretty closely then gun it around us in the bus only center lane.

    At 6th, there was a car poised to go straight. I told her that they needed to turn right and pointed to the sign. Needless to say she looked at me blankly and ended up passing us mid-block.

    @Rhonda, we also had problems with this (and every other time I hit that area). It is a horrible lay out and should at least have the large dashed green boxes that extend across the driving lane.

  • It’s too bad the inbound green lane is unsafe to use between 10th and 9th. The Hotel Whitcomb draws scofflaw tourbuses that now regularly occupy the “protected green bike lane” on Market.

    This morning a tour bus was so far into the green lane that cyclists had to merge *through* the soft-hit posts to continue traveling forward.

    Also, I think I saw a big electronic sign near 6th Street this morning indicating the required right turn there, but I’ll need corroboration–I wasn’t able to focus on that since I was being squeezed out by a private car at the time.

  • greasy, I took note of the tour bus at Hotel Whitcomb (around 3 pm yesterday) because of your diligent work on posting pictures. If I wasn’t with my wife and hadn’t been out biking for 4-5 hrs, I would have stopped and taken a picture also.

    Stay on them about that. Hopefully something will change.