How Engineering Standards for Cars Endanger People Crossing the Street

Pedestrian crossings in cities should not be designed like Boston's Landmark Interchange. Photo: Muddy River Associates
Pedestrian crossings in cities should not be designed like Boston's Landmark Interchange. Photo: Muddy River Associates

At the Landmark Interchange by Fenway Park in Boston, people trying to walk across the street sometimes have to wait as long as two minutes for a signal. And that, says Northeastern University Civil Engineering Professor Peter Furth, is dangerous.

Two minutes is an unreasonably long time to ask someone to wait — especially in one of the nation’s most walkable cities. Faced with that delay, says Furth, people will try their luck crossing against the light. To compound the danger, the signal phasing that delays pedestrians is designed to speed cars. So pedestrians crossing against the light will have to negotiate high-speed traffic.

The signal timing that puts pedestrians at risk is baked right into traffic engineering conventions, Furth told the Boston City Council in December [PDF]:

Synchro, the standard software [traffic engineers] use, is based on minimizing auto delay, and it doesn’t even calculate pedestrian delay. “Level of Service” criteria give engineers an incentive to minimize auto delay, often at the expense of pedestrian service (which isn’t measured). That’s how we get designs with 30 second delay for cars with 120 second delay for pedestrians.

Also, standard traffic engineering rules (from the Manual on Uniform Traffic Control Devices) say it’s OK to allow only enough time for pedestrians to cross to a median, and wait there for the next cycle to continue crossing. This can be appropriate in some contexts, but certainly not at high volume crossings.

Boston is at least paying attention to these risks and seeking the expertise of people like Furth. In most other places, pedestrian-hostile engineering standards go unquestioned.

Drawing: Ian Lockwood
Cartoon: Ian Lockwood

Part of the problem, Furth says, is that transportation engineers have standards for measuring motorist delay but not pedestrian delay. He has developed a tool to assess delay at intersections for pedestrians and cyclists, recommending that Boston weigh those factors in its signal timing.

Disregard for the walking environment is also embedded in the Manual on Uniform Traffic Control Devices — a point of reference for engineers. The MUTCD does not require pedestrian-specific signals at crossings, treating them as a judgment call even in urban locations.

The MUTCD does not even “warrant” (i.e. allow) a signalized crossing for pedestrians unless at least 93 people per hour try to cross the street, or five people were struck by drivers within a year.

Meanwhile, there are no such thresholds for motor vehicle signals. Regardless of traffic counts, the MUTCD gives engineers permission to install traffic signals on major streets to “encourage concentration and organization of traffic flow” — i.e. to make things go smoother for drivers.

Ian Lockwood, an engineer with the Toole Design Group, said this institutional bias helps explain why the U.S. has struggled to reduce traffic deaths.

“When a traffic engineer says they’ve optimized a traffic signal, that typically means they made it the best for the motorists,” he said. “There’s a pro-speed, pro-automobile bias that’s built into the traffic engineering culture dealing with these sorts of issues.”

When a pedestrian is killed, Lockwood says, engineers tend to blame the victim for not complying with the standard road design, instead of questioning how the street design created deadly risks.

20 thoughts on How Engineering Standards for Cars Endanger People Crossing the Street

  1. Great article! One nit-pick. I don’t think pedestrian-specific signals help pedestrians. All they do is allow engineers to shorten the time pedestrians are allowed to cross.

    The added complexity is also dangerous for both drivers & pedestrians. Unless you steadily stare at the signal, you can make an unsafe move, as the movement of other types of traffic on the street is no longer a cue for the change in the signal that applies to you.

  2. Yes, I agree completely. But then, I’m old enough that I remember when the first pedestrian signals were installed — they said, in green text, “Walk”, and then changed to, in red text, “Don’t Walk”. Haven’t seen one of those for a long time — it’s all icons now. Sigh. These kids today…..

  3. Part of the problem is counter technology. Putting out some traffic tubes, wait a week, upload the data to a p.c., and you’ve got a decent idea of vehicle traffic volumes. Mechanical counters don’t count walkers, and lump bikes in with motorcycles if they count them at all.

    The technology to count walkers and cyclists is out there. Placemeter looked really promising until they were bought out. They just needed a model that didn’t need A.C. power. It needs be packaged and sold to engineers and traffic planners.

  4. ? You can’t blame that on Windows or Iphones. The symbols were chosen to be be more visible to people with limited vision.

  5. I don’t know why the City of Boston can’t get its act together when it comes to pedestrian lights. There seem to be no standards, and intersections within even within a very small area seem to be a hodgepodge of settings. For example in the South End, E/W Newton St and Washington has an automatic concurrent walk signal to cross Washington St at every cycle (with a delay for the green to give peds time to start crossing) except for late lights, when it inexplicably becomes button operated, meanwhile a block away at E/W Brookline St, the walk signals to cross the Brooklines are automatically concurrent with the green light on Washington, but to cross Washington, pedestrians must activate the pedestrian light, and even then there is a very long wait (up to two minutes) to get a 10 second walk signal to cross the six lanes (two parking lanes, two bus lanes, and two general traffic lanes) of Washington St. Another block down E Brookline, at Harrison Ave, there is an exclusive all way pedestrian signal that is activated at every cycle (IE: Harrison gets the green, then it changes to the exclusive walk signal, and then E Brookline gets the green. A block down Harrison at E Newton, there is a button activated exclusive phase, which is sometimes on an automatic setting. This is unnecessarily confusing for pedestrians and for drivers. The standard, with very few exceptions, should just be concurrent walk signals (“walk with the green, not in between”), and buttons should be done away with altogether (with the exception of the occasional mid-block pedestrian crossing). Giving turning [auto] traffic priority over non turning [pedestrian] traffic sets a very bad example of priorities. It’s no wonder why pedestrians in Boston routinely ignore the pedestrian signals. They make no sense. Boston could learn a lot by looking across the river to Cambridge, where they generally have it right. (now if MUTCD could only be changed to do something about signal placement which encourages crosswalk blocking and stop line running).

  6. The MUTCD standards certainly do not help, and in many cases are dangerous to pedestrians. To see pedestrian signals that are designed properly, we need to look to mainland Europe, Germany especially, where traffic signals are placed at the stop line (and not across the intersection, as is done in many cases here) and all pedestrian signals are concurrent. This prevents crosswalk blocking, not to mention stop line overshoots, which can impede turning auto traffic.

  7. Angie, the picture of the landmark interchange is about 5 years old. The interchange was recently rebuilt by the Army Corps of Engineers as part of a wonderful project to daylight a section of the Muddy River that had been paved over. While the work with the river and it’s banks is beautiful, the street design that they built should not have been- it’s worse than it was before for people on foot and on bike. Highway design standards have no place in urban street design, and wven less when deigning streets through urban parks. The Army Corps should stick to what it knows best, and partner with Cities to design urban streets that meet the real needs of their citizens.

  8. Ms. Schmitt, you’re article is highly biased in regards to traffic signal installations for pedestrians. The MUTCD has nine signal warrants of which pedestrian volume is one of them. Of the seven warrants specifically for motor vehicles, you selectively chose one of two warrants where volumes are not required (the second is regarding railroad crossings).

    Warrant 4 (pedestrian volumes) was recently rewritten following an extensive research effort conducted. This new assessment should be considered in whole with other allowed crossing treatments such as the hybrid pedestrian beacon (HAWK signal). This crossing can be installed for pedestrian volumes much lower than the 93 cited above.

    Installing traffic signals (red, yellow, green) where warrants are not met have been shown to result in an increase in collisions for both motor vehicles and pedestrians. The reasons are not particularly clear but it is possible where traffic signals are installed and do not change frequently, the signal becomes part of the background and can increase red light running.

    In regards to Synchro software, the software is a calculation of the level of service equations. There is no basis to reduce automobile delay in the program. It is simply a computer program providing the user with the output of the calculations.

    I value the contributions that this site provides to the public discourse. However, false or misleading information does not help advance the conversation for more people-centered standards.

  9. I would also think that usability for people with limited or no English skills was part of the reason.

  10. “Meanwhile, there are no such thresholds for motor vehicle signals.” This is a false statement as there are volume thresholds for motor vehicles.

  11. Picking on traffic engineers is so 2014. There are plenty of people who make poor decisions and base those decisions on a rudimentary understanding of technical guidelines, tools, and requirements (see US congress for further details). This article, and the statements made in it, unfortunately does not dig deep enough and presents sensationalized statements that demonizes an entire profession. Any traffic engineer of a high caliber knows that good design for all modes can be justified through careful analysis and execution. Throw that in the mix of the public project prioritization and funding meat grinder, and you can sometimes end up with a result that makes everyone happy and safe.

    I’m an avid streetsblog reader, supporter, and a traffic engineer. Please don’t turn me away by continuing to post these types of articles. If you must, I’d love to see some reference to the good work that other traffic engineers are doing across the US and world.

  12. I was thinking the same–there are lots of small low-traffic intersections in Philadelphia and Pittsburgh that have only a tricolor traffic signal. Because they’re small, they’re easy and safe to cross. Adding a pedestrian signal would likely mean a default to “Don’t Walk” and a beg button.

  13. If you are one of the good ones then this article does not apply to you, so don’t take it personally, but the industry remains very auto centric, and it will still take some time and a lot of turn over to change that. Be part of the solution, make sure younger professionals are mentored by you and not by the cynical old ones. And also, if you want to claim your Streetsblog bonfides you can start by refering to yourself as a transportation engineer instead of a traffic engineer.

  14. Thank you for taking the time to respond. The recommendations given are also appreciated, and if we knew each other personally you might see me as “part of the solution.” The reason for my comment is that I see articles like this as a deterrent to the solution. The traffic engineering profession does exist (and yes, most of us now call ourselves transportation engineers), and painting an entire profession as “the problem” is no way to win an argument. My recommendation is to point to the practice of making poor decisions based on a rudimentary understanding of technical guidelines, tools, and requirements – a practice that can be found in every profession – as the problem. Otherwise, the entire debate will become a typical us/them, red/blue, facts/alternate facts discussion that will not solve the real issues that need to be addressed.

  15. Well this is embarrassing, I responded without even noticing who I was responding to. We do know each other, and you most certainly are part of the solution. I am a public sector employee working at one of, if not the largest (hint, hint), MPO in the nation, and we have worked together a number of times. I think you make some very good points. I remember the transportation planner for Long Beach making much the same point as you are making about their engineers. I guess I would refine my comments and use a line I used in some presentations in 2011-12 “Engineering is a problem solving profession, so the real issue is that the transportation engineering practice needs to redefine the problem it is solving. For decades it was defined as ‘How do we move the highest number of vehicles through the system, at the highest speed, with the lowest number of collisions.’ The new formulation needs to be ‘How do we move the highest number of people within the system, most efficiently in terms of environmental impacts, with the best health and wellness outcomes.”

    Immediately apparent is that the second formulation is much more challenging because the measurement and data necessary for the equations is much more challenging. I know you are working on the latter formulation, so the idea is to make sure that the second problem is the starting point and not an after thought or add on for the industry as a whole. Like you say to some extent the same guidelines can be used to work on either problem, but I would still argue that the guidelines lend themselves to the first formulation as a default, and it takes exceptionally good engineers to apply them to the latter.

  16. Thanks for the compliment, and I recognize your name now too. Can’t wait to talk about this further next time we see each other. We are part of the solution!

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