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D.C. Tries Out New Traffic Signal

Launching the Georgia Avenue signal became a party for pedestrians. (Thomson)

It's been a long time coming, the neighbors said, as they watched the District Department of Transportation ready a new type of crosswalk signal on Georgia Avenue a few blocks north of Walter Reed Medical Center. The original crosswalk is bold enough, but you'd have to be a pretty bold person to step out into four lanes of fast-moving Georgia Avenue traffic.

Once the signal was activated, one person after another tested it out, hesitating as though Georgia were a river of cold water and they were dipping in toes to check the temperature. Finally, Council Member Muriel Bowser and George Branyan, the District's pedestrian safety program manager, pushed the button to engage the red light for traffic and the walk sign for pedestrians, then led a large group of the neighbors out into the stopped traffic.

HAWKjpg What Georgia Avenue drivers see. (Thomson)

And the signal activation became a mini-block party at Georgia Avenue and Hemlock Street for people hoping this just might work.

Kelly Shuy, who has owned the nearby Ledo's Pizza for three years, knows that her customers and employees feel like they've been taking their lives in their hands when they cross there.

"It's a scary place to cross anytime," she said.

The nearest traffic signals are about 400 feet to the north and south, an inconveniently long walk. Still, the Georgia/Hemlock intersection doesn't meet the standards all traffic departments apply in deciding where to place regular traffic lights.

The neighbors, the Advisory Neighborhood Commission, Bowser and DDOT worked out this solution: A pilot project that will use a pedestrian-activated signal pioneered in Tuscon, Ariz. (Alexandria also installed one last year.)

It's known as a HAWK, which somehow is an abbreviation of High-intensity Activated cross-WalK. Don't try to figure it out from that. I'll just tell you how it works.

If there are no pedestrians waiting to cross, drivers see no lights. It's just business as usual for traffic. But once a pedestrian hits the the button to activate the signal, it goes through this sequence: A yellow light flashes, then it glows solid, then two red lights come on, and drivers -- who should have been slowing by now -- must stop. Later, after the pedestrians have gotten across, the red lights will begin to flash, then go dark, and traffic can move again.

D.C. police are on the scene today, but it most cases will just be issuing warnings and brochures to drivers who fail to stop for the red signal -- though they shouldn't push their luck on that. Eventually, tickets will be issued for red-light running.

I tried crossing before the new signal was operating, as well as after, and the "after" experience was very different -- in a good way.

The District got permission from the Federal Highway Administration for this pilot project, and will monitor it for a report to the feds. DDOT is hoping to be able to use the same style signal in other D.C. locations where pedestrians and vehicles meet in high volumes.

Here's a map showing the intersection.

View Larger Map

By Robert Thomson  |  August 14, 2009; 10:59 AM ET
Categories:  Safety  | Tags: Dr. Gridlock, George Branyan, Muriel Bowser, pedestrian safety, traffic signal  
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I applaud any effort to make life safer for pedestrians and am eager to check out this improvement but I also have to say that 400 feet is hardly an "inconveniently long walk" for most people (excluding of course the elderly, disabled, pregnant, etc.) But the rest of us should just learn not to be so lazy.

Posted by: rrno62 | August 14, 2009 4:09 PM | Report abuse

Pedestrians want the straightest possible path from Point A to point B. That is why you see sidewalks at nice right angles, and pedestrian "goat paths" on the diagonals....peds don't want to walk on the sidewalk if it means taking a longer path to get to their destination. 400 feet is about 2 blocks, and most people I know would prefer not to walk 2 blocks north only to cross and walk back 2 blocks south (that is assuming there needs to be a crossing at that particular point, say, for a bus stop).

HAWK signals are a neat idea. Though they are a little hard to understand exactly how they work at first. Let me describe:

1) The signal is completely dark. Cars drive as normal.

2) Pedestrian pushes the button. The signal starts to flash yellow as it "wakes up". This is the warning to the driver that it is about to turn red. Drivers should slow down on a flashing yellow signal.

3) The yellow stops flashing (steady yellow, which legally must come immediately before any red), and then both reds come on and stay on. At this point, the pedestrian signal changes to walk, and the pedestrians start crossing.

4) The pedestrian signal changes to flashing don't walk, which means new pedestrians cannot enter the crosswalk, but pedestrians already in the crosswalk are still permitted to be there and complete their crossing. At this point, the HAWK signal changes to flashing red. HEre is where it gets tricky. If the pedestrian has cleared the crosswalk, drivers can go. Drivers are always allowed to go on a flashing red signal, after stopping. They've stopped to yield to the pedestrian, and the pedestrian is no longer there, so they may go. If the pedestrian is still there, they must remain stopped...just like at a stop sign with cross traffic present.

5) When the pedestrian signal does to "steady don't walk", meaning pedestrians should no longer be in the crosswalk, the HAWK signal goes dark again, and drivers can proceed as normal.

HAWKs are used extensively in Tucson, Arizona, among some other places. Here are two YouTube videos, one from Tucson, the other from Lawrence, Kansas:

Posted by: thetan | August 14, 2009 4:52 PM | Report abuse

There's a similar signal on Van Dorn Street between Landmark Mall and Seminary Road, but it doesn't get much use since its only purpose is to serve a bus stop. As a result, I've only seen it in operation once. I assume these devices have some sort of reasonable delay between the time they turn off and when they will go back on? That is, "thetan" crosses the street in one direction. Barely 10 seconds after he finishes crossing and the lights go out and the cars start moving, I walk up from the other direction and I hit the button. I assume the system is designed not to give me the walk sign immediately under that circumstance and that instead it lets the vehicular traffic flow for a little while before changing? Otherwise this sort of system starts lending itself to abuse by people who keep hitting the button and to being ignored by motorists who get fed up waiting.

On the whole, though, this seems like a fairly intelligent system and a good alternative to putting up a full traffic signal. I imagine drivers would respect the red lights more than a flashing yellow or a pair of Belisha beacons, too (not that the latter are used in the USA).

Posted by: 1995hoo | August 14, 2009 6:17 PM | Report abuse

BTW, I should have added that the HAWK design strikes me as a better system than the one on Brentwood Road. Dr. Gridlock reported on it last year:

Posted by: 1995hoo | August 14, 2009 6:28 PM | Report abuse

Good question, 1995hoo. I don't know for sure, but I would certainly assume and hope that they would be programmed to not change at a rate higher than X times per hour, where X is the number of cycles a normal traffic signal along the same corridor would go through in the same hour and that time of day.

I would also hope that the HAWK signals would be coordinated with adjacent signals so as to maintain traffic progression even when activated. No one says you have to give peds immediate service, since they are supposed to wait for the walk signal.

Posted by: thetan | August 15, 2009 12:44 PM | Report abuse

"No one says you have to give peds immediate service, since they are supposed to wait for the walk signal."

The law says so. Vehicles are to yield immediately to any pedestrians in a cross walk, and pedestrians have a responsibility to give vehicles a reasonable amount of warning to stop.
However, no one follows those laws. It's a free for all - vehicles fly right through and pedestrians cross wherever whenever they like. Maybe using traffic lights will help. Vehicles are far less likely to go through a red light. Pedestrians are far more likely to use a safe crossing. Hopefully this system serves the residents and drivers well.

BTW, there's a similar signal installed near the Bethesda Library. Pedestrians may enter the crosswalk at any time, and a flashing yellow light and signs posted far ahead to alert drivers of the crossing. The light changes to red when a exclusive pedestrian crossing is requested.

Posted by: cprferry | August 16, 2009 12:51 AM | Report abuse

"The law says so. Vehicles are to yield immediately to any pedestrians in a cross walk, and pedestrians have a responsibility to give vehicles a reasonable amount of warning to stop."

You're oversimplifying, and you're also missing the point "thetan" was making. The two things are related.

First, vehicles do not have to yield to pedestrians who enter a crosswalk illegally--for example, if the vehicle has a green light and the pedestrian ignores a "Don't Walk" sign. In that situation it is the pedestrian's responsibility to yield the right-of-way to the vehicle. (Of course, if the driver runs over the pedestrian, the driver may well be found liable in a civil suit brought by the pedestrian if it is found that the driver had the last clear chance to avoid the accident, but that's a different issue.)

Second, the point "thetan" was making is that there is nothing that requires an instantaneous "Walk" signal on demand anywhere in the city. That is, you don't walk up to the light at 7th & Pennsylvania, hit the button, and immediately get a "Walk" signal, especially if the "Walk" signal has just gone off and the light just changed. You have to wait a little while for the normal light cycle. The new HAWK signal is a bit different in that there's not a full light cycle as at an intersection, but "thetan" and I are assuming that there is still some minimum amount of time that will elapse before the HAWK will give the drivers the red light again.

We all know that there are a lot of uppity people who think that none of the rules apply to them (both pedestrians and drivers), but "thetan" and I were discussing how the system is SUPPOSED TO work, not whether it actually DOES work as planned!

Posted by: 1995hoo | August 17, 2009 10:38 AM | Report abuse

BTW, in my first post I said this:

"Otherwise this sort of system starts lending itself to abuse by people who keep hitting the button and to being ignored by motorists who get fed up waiting."

When I wrote that, I had the mental image of something happening akin to the way little kids think it's funny to hit all the buttons on the elevator right before getting off. I had this image of some annoying kids standing there hitting the "Walk" button over and over again as an obnoxious prank so that the traffic keeps having to stop even though nobody's crossing the street.

Posted by: 1995hoo | August 17, 2009 10:40 AM | Report abuse

That is actually illegal in some places (hitting the button if you do not intend to cross). I know a colleague of mine who almost got a ticket for doing that (he was an engineer trying to determine if the timings were appropriate or not).

Posted by: thetan | August 17, 2009 12:57 PM | Report abuse

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