Ideas From Rush Hour Traffic: A Pedestrian Scramble

By Shadowlink1014 at en.wikipedia [Public domain], from Wikimedia Commons

I, like everyone I know, do not like being stuck in traffic. Not having to deal with rush hour is one of the things I like most about walking to work. If it’s sunny out my walk takes 20 minutes. If it’s snowing, still 20 minutes. And if two drivers get in an accident, still just 20 minutes. When my wife and I moved downtown the ability to walk was a factor in our decision, but it wasn’t something I expected to enjoy as much as I do. From time to time though I do have to drive during rush hour, and every time I really feel for all the people who do to it day in and day out.

The last time I found myself stuck in traffic was just about two weeks ago. I had to drive to work that day because I had a meeting, and on my drive home at about 4:30 I found myself stopped dead in traffic. Because I’m not very smart I first chose to take 109 Street southbound towards the High Level Bridge. I know how far that route backs up because my office window faces north at 109 Street and Jasper Avenue. I guess I thought this would be the day it wouldn’t be backed up. I was wrong. When 109th failed me I turned onto 102 Avenue which I planned to take to 100 Street, which becomes McDougall Hill; and since I live in the River Valley it would be all smooth sailing from there.

And for eight blocks that plan was perfect. I’d beaten the downtown rush hour. Then I came to a stop again waiting to turn right onto 100 Street southbound. Ahead of me at 100 Street was just one ETS bus waiting to turn, but I didn’t move an inch until the third green light, and even then only because the driver of the bus leaned on the horn and cut off the pedestrians waiting to cross the street. Not the best idea by the driver I’ll admit, but after sitting through three lights waiting to turn it was somewhat understandable. I waited through the rest of the green before finally getting a chance to turn as the light turned red.

So how could it take three green phases to make a right turn? Because of the pedestrians. If there is an intersection with more pedestrian traffic than 100 Street/102 Avenue I don’t know where it would be. Right at that corner you’ve got City Centre, the Edmonton Public Library, stops for more bus routes than I can count, an LRT station, and Churchill Square. There is a lot of this going on at this corner. And to make things worse, on this particular day the Taste of Edmonton was also in full swing. That took a normal mess and made it even worse. Basically it was the perfect storm.

What was happening was that there were so many pedestrians crossing the street east/west on the green that there was never an opportunity to turn right. The countdown signals for pedestrians don’t help much because everyone looks at the time and says, “I can make it,” essentially preventing any turn until the signal goes red, at which point it all starts over again in the opposite direction when a new wave of pedestrians blocks the vehicle now wanting to turn right on the red. The right turns in every direction were being choked off by the pedestrians – eastbound was by far the worst – and the overall delay at the intersection (and my frustration level) was increasing.

It goes beyond this one intersection though. Imagine the trickledown effect behind me for a second. With no buses reaching their stop at the corner because everything has come to a full stop, each of those routes is getting more and more behind schedule. Nothing about this situation was good, but what do you do, the vehicles aren’t going anywhere and neither are the pedestrians. Well, somewhere around the second red light I got to thinking about a pedestrian scramble as an alternative, and it’s an option I think would probably work really well in this location.

For those not familiar with a pedestrian scramble the concept is pretty simple. Instead of pedestrians and vehicles crossing in the same direction during the same signal phase there is now a separate phase just for pedestrians, and they can cross in any direction they want, including diagonally. Basically you have an east/west green, followed by a green for north/south, and then pedestrians are let loose, free to go any direction their hear desires. The drawback from an intersection design standpoint is that every car needs to be stopped during the pedestrian phase, and since an intersection’s level of service is usually determined by the average delay for a vehicle, a design that requires stopping all vehicles isn’t typically seen as a positive.

But even if you look at an intersection from a strict cars only view point there is going to be a point where everything balances and a pedestrian scramble makes sense because the delay from the pedestrian phase is less than the delay created by pedestrians in a normal crossing design. And if you look at an intersection more holistically including both vehicles and pedestrians as equal users (and in a downtown isn’t this the right way to look at it) you’ll almost certainly get to that balance point sooner.

In the case of this intersection the diagonal cross distance (which governs the length of the pedestrian phase) is approximately 29m – I walked each of the existing crossings to approximate this; I did not go through the middle even though I really wanted to. Using the MUTCD standard of 3.5ft/s (1.07m/s) the minimum walking time is about 27 seconds. There would need to be a buffer on that to make sure everyone has cleared the intersection, but even then that isn’t a ridiculous amount of delay; especially not if it opens up the intersection for vehicles during their respective phases.

I don’t have the traffic volumes in front of me and I haven’t run a simulation on the intersection so I can’t say that it would definitely be an improvement, but I think it might be worth a look. And if nothing else, at least I got an idea out of being stuck in traffic and that’s better than nothing.

4 thoughts on “Ideas From Rush Hour Traffic: A Pedestrian Scramble

  1. Pingback: Taking A Walk Down Jasper Avenue | All Roads Lead To Ryan

  2. COB Ryan

    Hey Ryan, that’s a great point and would probably improve the traffic conditions for the busy times of day. I’m curious though, would it make sense to run a pedestrian scramble throughout the whole day? It seems to work well in large cities (NYC for example) where pedestrian traffic is heavy essentially 24/7, however I’m curious how it would work overnight in Edmonton, where the current system seems like it would still be appropriate instead of having all cars stopped at the intersection staring at each other while nobody crosses the street. Have you seen any instances where a combination of systems are used depending on the time of day (similar to left turning priority signals), or is that simply too complicated and confusing to install?

    1. ryanbatty

      Interesting question. What I would do is set up the signal so that during the off peak hours the pedestrian phase is only activated when a pedestrian pushes the button. By putting the pedestrian phase on recall like that you wouldn’t have car waiting unnecessarily.

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