Begging for Simplicity

Pedestrian actuators call for a pedestrian signal at an intersection which is semi-actuated (where the green-time goes to the mainline except when a vehicle is on the side street, subject to a maximum cycle length and a minimum green time for the side street) or fully-actuated (where the green time is allocated to approaches which are actuated subject to a lot of constraints). When they do this, they also tell the controller to extend the green time (and parallel walk signal) given to a phase to be sufficiently long to allow pedestrians to safely cross.

Replacement Walk Button (Franklin and Seymour)

Replacement Walk Button (Franklin and Seymour)

Decommissioned Walk Button (Franklin and Seymour)

Decommissioned Walk Button (Franklin and Seymour)

But this has problems. Imagine you are on a side street about to cross a main street and the light turns green for the cars, but the Don’t Walk sign remains (since no Pedestrian actuation was recorded). You did not get to the actuator quickly enough. Should you cross on the Green but against the Don’t Walk, or should you wait almost an entire cycle for this to come around. You may or may not have enough time to make it across.

Second imagine the actuator is broken. It may never give a walk signal. (There are solutions for that, where the default state of broken is “on” instead of “off”, but that doesn’t seem to be widely deployed). For instance, recently I reported to SeeClickFix a broken pedestrian actuator at Franklin and Seymour Avenue in Southeast Minneapolis, which was corrected within 18 days (i.e. the case was closed within 18 days). I am fairly confident a broken traffic light serving cars would have been corrected sooner.

The next  two “beg buttons” (pedestrian actuators for traffic signals) were recently photographed. The one on the University of Minnesota campus (at Beacon and Harvard) recently had a time exemption added, implying that the actuator need not be pressed between 8 am and 6 pm weekdays. (This time exemption seems to have been removed since the photo was taken). This is an improvement over the previous situation (pushing the button in the middle of the day). Still one expects this will, like so many others, become a placebo button, or just break and make it so there is no pedestrian phase.

Beg button at Harvard and Beacon, University of Minnesota campus

Beg button at Harvard and Beacon, University of Minnesota campus

However, the complexity is still needless. Traffic signals on streets with sidewalks (which implies pedestrian traffic either exists or is desired) should ALWAYS have an automatic walk phase, just as every cycle gives green time to cars from every approach. (This is especially true in pedestrian areas like a college campus which has a plan that aims to prioritize walking.) Actuators are fine if they make the walk signal come sooner, but being unpushed should not be used as an excuse not to have a walk phase at all. Car drivers don’t have to go out of their way to press actuators, why should pedestrians?

(If traffic is so low you are concerned the time devoted to a pedestrian phase (~12 seconds (36 ft at 3 fps)?) is too long (will cause too much vehicle delay) for this two lane roadway, maybe it shouldn’t be a signal but instead a stop sign (which requires no pedestrian signal) or a yield sign. This can be implemented with flashing red lights if you must you electrical gear.)

Beg button at Franklin Avenue, East River Road, and 27th Avenue SE

Beg button at Franklin Avenue, East River Road, and 27th Avenue SE

Fortunately it is not as complex as the last, at Minneapolis’s favorite five-way intersection (Franklin Avenue, East River Road and 27th Ave SE), which gives instructions for something that should be tacit. That it is not tacit indicates it is a flawed design. If I can read the instructions, I already know how to cross a street. It is not like pedestrian actuators are a new technology. While I want more information at bus stops, crossing a street should be straight-forward, and not require an 11 line instruction set with five graphics. Sadly there is more information here than at the nearest bus stop.

Update. I found the tweet below, which seems appropriate.

Erik Griswold (@erik_griswold) 11/16/13, 18:13 "Making pedestrians press. buttons to cross streets is the death of the city" -Eric Fischer (@enf) at #transpowest

Erik Griswold (@erik_griswold)
11/16/13, 18:13
“Making pedestrians press. buttons to cross streets is the death of the city”
-Eric Fischer (@enf)
at #transpowest

21 thoughts on “Begging for Simplicity

  1. Stacy

    You suggest that: “If traffic is so low you are concerned the time devoted to a pedestrian phase… maybe it shouldn’t be a signal but instead a stop sign.”

    The use of a traffic signal is based on the vehicle traffic. Vehicle traffic may be high enough to warrant a signalized intersection, while pedestrian traffic is too low to warrant a devoted walk time unless requested by pressing the button.

    1. Alex

      In a perfect world, maybe the use of a traffic signal would be based on it meeting a certain threshold of vehicular traffic. But in our imperfect world, there are all sorts of political reasons why signals are installed and retained. For example, plans for the recent reconstruction of Nicollet Ave marked the existing signal at 34th St as under consideration for removal due to low traffic. However, it’s still there because 34th St is a popular route for walking to the elementary school a few blocks west. I haven’t checked to see if there is a beg button on this signal that exists solely for pedestrian accommodation.

      Besides this, I think most guidelines allow installation of signals for safety reasons, too, for example at skewed intersections.

  2. Sam NewbergSam Newberg

    Hear, hear David Levinson! Your comment “Traffic signals on streets with sidewalks…should ALWAYS have an automatic walk phase” is spot-on and should be used by every city councilmember when arguing with every traffic engineer. Your argument “Car drivers don’t have to go out of their way to press actuators, why should pedestrians?” is one I have used when discussing the matter at streets that cross Hiawatha Avenue. I refuse to push the actuator buttons and trust my instincts to cross streets, but alas I teach my kids to push the button.

    It is a simple matter of justice. We still build and control streets first for the use of cars and second everything else.

  3. Adam MillerAdam

    I have a different gripe. I run into multiple intersections where the light turns green but the pedestrian signal waits for the left turn signal to change even if you’re crossing to the right of parallel traffic, thus raising these types of actuator issues and/or question of whether there will ever be a walk signal and creating confusion.

    Perhaps the concern is that if you allow pedestrians to cross on the non-turning side of the intersection it will lead the folks on the other side to walk out in front of turning traffic, but that seems a little far-fetched. If cross traffic is stopped, and especially where the cross traffic is one way the other way so there will be no right turns either, I don’t understand why pedestrians are supposed to wait for an irrelevant turn signal to change.

      1. Anders ImbodenAnders

        Janne, the Hennepin/Lagoon example is a good one, and I’ve always had a hunch that the unspoken goal is to give right-turning vehicles from WB Lagoon to NB Hennepin an extra few seconds to go (if they can), since there’s no “No Turn On Red” sign in that direction.

        Just an assumption, though. I can’t figure out why else you wouldn’t have a NTOR sign there, given that it’s a very high-traffic intersection with lots of pedestrians and mediocre sightlines.

        All hail the mighty automobile!

    1. Monte Castleman

      This is just the way most traffic signal cabinets are set up- there’s one phase / load switch for each direction of travel on both sides of the street. Having one side only go to walk with a non-conflicting left turn involves additional load switches, custom wiring, implementing overlaps, and such, and is often not possible with existing controllers, or even existing cabinets. No reason new installations couldn’t be built this way though, except Minneapolis is way behind the times as far as traffic signal standards. They’re still not building flashing yellow arrows, and the arrows on the new lights on Lyndale still are not actuated.

    2. Monte Castleman

      A new thing coming out is microwave detectors for both vehicles and pedestrians. For vehicles they’re more accurate than cameras and aren’t susceptible to corrosion like buried loops, and for pedestrians, if it’s really too indignant for them to push a button this puts them on equal footing with cars, in that they get a go light just for being there rather than having to actively register their presence. (The main problem I have with beg buttons is they’re hard to push without dismounting a bicycle.). Another trick is to have additional sensors pointed at the crosswalk that will extend the walk time if a pedestrian is still in a crosswalk.

  4. Walker AngellWalker Angell

    Great stuff David! Another issue I have is how some buttons are placed that makes them difficult and dangerous for bicyclists to access them.

    I’d also like to see more intersections with simultaneous green that stops all vehicular traffic and allows all pedestrians and bicyclists to cross in any direction. In many intersections I’d think this not just much safer (eliminates right/left hook), but more efficient for pedestrians, bicyclists, and vehicular traffic.

  5. Alicia H

    This seems like an ADA issue. can everyone in a wheelchair reach the button? What about blind people? How are they supposed to know that they need to push a button?

    Non-English speakers? People who don’t read English?

    Beg button is the right term!

  6. Randy A. Simes

    I have long been offended by the requirement for pedestrians to push a button to cross a street. I can somewhat understand if it’s a button to activate a special assist device, but not as a standard practice.

    Put crosswalks at every intersection and time those pedestrian signals with the light itself. If the light is so incredibly long that traffic engineers want to use a pedestrian signal button to hurry the light, then perhaps the whole signal timing should be reconsidered.

  7. Steve Gjerdingen

    I can somewhat understand why traffic engineers want a pedestrian to push a button in order to trip the signal. I can see why it would seem silly for the light to turn red and then wait for 30 seconds while the cross traffic never arrives.

    However, one of my pet peeves is that when a car goes through on green because a camera or loop detector detected the car, why not activate the walk signal at the same time? In many cases, a pedestrian approaches the intersection just too late, but if the signal had already been initiated for walking, they would still have time even if they were just arriving to the intersection.

    My biggest pet peeve are pedestrians who get to the light in plenty of time to push the button, but they refuse to, despite that I’m sprinting to get to the intersection on time. They then illegally jaywalk in a scurrying like fashion across the intersection, while I arrive just in time for a green that is half over.

  8. Sean Hayford OlearySean Hayford Oleary

    It is worth remembering that not all lights are timed per se. Outside the City of Minneapolis, the vast majority are actuated — and probably about 1 in 5 in Minneapolis are too. That’s not to say it’s equal, since signals detect cars a lot more effortlessly than they detect bikes and pedestrians. But it also means that it would be impractical to simply have no button and a walk signal on every green. If no cars were present on the minor street, pedestrians would have to wait until one showed up to get a walk signal.

    One thing that is completely indefensible is not including walk signals on the major street legs of these intersections. There are a handful of exceptions where the intersection is so broad, that even the major leg doesn’t have enough time to give a pedestrian cycle under normal timing (think 24th Ave and E American Blvd). But at most intersections, there is plenty of time for the major leg to have a walk cycle.

  9. Sean Hayford OlearySean Hayford Oleary

    As to your point about the signage, David, I couldn’t disagree more. On the contrary, not only should we keep the signs for pedestrians, but I think we need similarly condescending and verbose signage explaining red, yellow, and green for drivers at every intersection. See my proposed signage from last spring.

  10. Peter

    I once asked a MnDOT traffic signal guru why they don’t do this, and he said one of the main reasons is emergency vehicle preemption, or EVP. When a traffic signal is preempted by an emergency vehicle beacon, it has to let a conflicting pedestrian cycle finish before it can change and give the vehicle a green. This can take 15+ seconds. I can see the logic here at least for more highway type intersections, but I think within the city it is a no brainer to not require a beg button. I’ve noticed along University with LRT reconstruction, a lot more signals have beg buttons.

    1. Sean Hayford OlearySean Hayford Oleary

      I’ve heard that as well, although I notice that Minneapolis’s signals do change when an emergency vehicle is in the vicinity — no pedestrian cycle is given at all until the vehicle clears. That may not be practical at highway speeds, but I’m not sure.

      From what I heard from MnDOT, this is standard practice, but it is not a mandate. They can and do consider exceptions in high-pedestrian areas. In downtown Lindstrom and downtown Red Wing, for example, pedestrians on the major road are given a walk signal by default.

      And of course, MnDOT in the metro is almost exclusively freeways and high-speed highways, whereas in greater MN, there are many more downtown-type streets. (There are a few exceptions, like TH 65 Central Ave, but those signals are owned by Minneapolis.) So even though there may be more pedestrians in the metro, the practicality of walk signals may be less for MnDOT signals.

  11. Sean Hayford OlearySean Hayford Oleary

    What’s odd about this, Monte, is that it seems to be Minneapolis’s newest equipment that has this left-turn problem. (For example, the signals on Hennepin Ave.) Many older signals with left-turn arrows have pedestrian cycles immediately on the non-conflicting leg. I’d also note that most signals outside of Minneapolis will give pedestrians a walk signal immediately when not conflicting with a left arrow. (Yes, you have to “beg” for those signals, but they do display right away.)

    And agreed on the gripe about the S Lyndale left-turn arrows. They’re torture. At the very least, they could time them to be active only at rush hour.

    1. Monte Castleman

      I have no explanation for Hennepin. It could be engineers didn’t think to give non-conflicting walks, but it could also be they reused some older controller equipment. Looking on Google Street view the cabinets don’t appear overly large. Ironically it also could be done on old electro-mechanical equipment, since it was a lot more flexible than early solid state equipment, that and “don’t pay to fix it if it works” is why some of the equipment has lasted until now.

      The city of Minneapolis always does it’s own thing with traffic signals rather than following state standards and I don’t know what controllers they use, but Mn/DOT tends to use Econolite NEMA standard controllers (despite using Eagle/Siemens heads), which definitely do have the capability for “pedestrian overlaps”, to allow a green during non conflicting arrows whether they do the extra work to implement them I don’t know. The PEEK 3000 controller I personally own is really easy (and in fact I have it set up to do) to give non-conflicting walks, since it has a feature where any output can be set to any function in software, so pedestrian overlaps can be sent to the regular pedestrian outputs and no special rewiring is required.

Comments are closed.