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Longer yellow lights to be tested

By Kevin Flynn, Rocky Mountain News (Contact)

Published June 9, 2008 at midnight

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Denver will set up video monitoring of four high-accident intersections where it plans to increase yellow signal times to study whether proper timing reduces red-light running better than ticket cameras.

The test program is meant to run along with four other intersections where the city has begun installing red-light cameras that will issue $75 tickets to owners of vehicles that enter after the light changes to red.

But even at those intersections, Denver traffic engineers have opted to increase the time of the yellow signal to meet national guidelines. That could make it difficult to determine whether any reductions in red-light running come because of the camera enforcement or from more appropriate signal timing.

"It was a little more challenging to identify four intersections that are reasonably comparable to the red-light camera locations than I originally envisioned," said Brian Mitchell, Denver's traffic engineer.

The four comparison locations are southbound Broadway at westbound Speer Boulevard and also at Eighth Avenue; northbound Lincoln Street at Alameda Avenue; and westbound Champa Street at 15th Street.

The two Broadway intersections were ranked 51st and 63rd on Denver's list of top 100 locations for side-angle crashes - the type most associated with red-light running. The Lincoln-Alameda site ranked 18th highest and Champa-15th was 41st.

All four were studied as candidates for enforcement cameras but rejected.

The Lincoln-Alameda site needed vegetation to be trimmed for visibility; Champa had a substandard signal installation; the Broadway intersections dropped out because police preferred a nearby location.

The city has used the legal minimum of three seconds of yellow at all its traffic signals.

But a formula by the Institute of Transportation Engineers shows that's the appropriate time for 25 mph traffic. Higher speeds call for longer yellows, up to the legal maximum of six seconds.

Some cities in the metro area use the rule of thumb of one second for every 10 mph of speed, so a 35 mph city street would get 31/2 seconds of yellow.

The city decided to increase yellow times at the camera intersections to between 31/2 and five seconds, following an engineering formula based on traffic speed and other factors.

The move came after the Rocky Mountain News examined numerous studies showing that red-light cameras can often increase the number of crashes, and that it can be worse when yellow lights are timed shorter than recommended, as in Denver.

Denver says it is using cameras as a traffic safety tool, but that increasing yellow times will help to achieve that.

Crews already are installing enforcement cameras at four other locations.

The first one, on northbound Quebec Street at 36th Avenue, is expected to go live sometime next week.

The others are at eastbound Sixth Avenue at Kalamath Street, eastbound Sixth Avenue at Lincoln Street and westbound Eighth Avenue at southbound Speer Boulevard.

The system, installed by Redflex Traffic Systems, an Australian-owned company with U.S. offices in Scottsdale, Ariz., will automatically tabulate all red- light runners.

But at the comparison locations, there is no system in place to make the counts.

So Denver is hiring All Traffic Data of Wheat Ridge to set up a before-and-after video study of the comparison intersections. A count of red-light runners will be made before increasing the yellow time, then again after the yellow time is boosted.

flynnk@RockyMountainNews.com or 303-954-5247

Comments

  • June 9, 2008

    7:06 a.m.

    Suggest removal

    alwaysright writes:

    What is next ? Make all banks and stores alarm systems delayed so that law breakers have more time to break the law.

  • June 9, 2008

    7:08 a.m.

    Suggest removal

    LingLingfor_prez writes:

    Is it still yellow? Good. How about now? Yes, it is still yellow.

  • June 9, 2008

    7:39 a.m.

    Suggest removal

    HOOK writes:

    Just an observation, longer yellows = more people speeding up to make it before the light turns red, more people not being able to stop prior to red = more money $ for red light blowers, and/or more accidents. Sounds a little extreme I know, but look at how most people are driving these days.

    Take a look at how these idiots time the lights too, the light turns red at 5:30 in the morning for no reason, you sit there with no cars passing through the other way. You look down the block and see the next three lights green. Then, the red you just sat at forever for no reason, no cars, finally changes green, then the next light that was green, turns red just in time for you to hit the red, and so on, and so on, and so on.............

    The city wants to stop the road rage, time these lights better period! Its ridicules and archaic the way traffic engineering has these lights timed. How about spending a few dollars putting sensors on the ridiculously, inefficient lights? Guess that won’t bring enough dough in for the Hick though huh?

    Example: You sit burning gas and time at the average (no reason for red light in Denver because nobody is coming) than it took to read my rant.

  • June 9, 2008

    7:48 a.m.

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    Scott writes:

    alwaysright and HOOK,

    Reread the part, "Denver traffic engineers have opted to increase the time of the yellow signal to meet national guidelines". Denver's traffic "engineers" didn't even have the timing set up correctly to begin with. This was the original gripe from a few weeks ago. Denver was going to put red-light cameras at intersections that had short yellow lights even by "national guidelines." This struck a number of people, me included, that Denver was just looking for another cash-cow. Yes, I also can't stand red-light runners, but when the crooks in Denver cherry-pick intersections that have short yellow light cycles, it smacks of nothing more than a revenue generator.

    Scott

  • June 9, 2008

    7:58 a.m.

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    HOOK writes:

    Scott, I don’t disagree with what you’re saying, I did read the article, that doesn’t mean I can’t make an "observation" as I stated, re-read my post. All I am reflecting on is how ridicules it is that you sit way too long at useless lights, which has a direct effect on why so many people want to blow them (IE: cause and effect)! I am in no way justifying anyone blowing a red, and I knew already that these were below the average, that wasn’t my point.

  • June 9, 2008

    8:14 a.m.

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    Scott writes:

    HOOK,

    Of course you can make an observation! Nor I was slamming you or alwaysright in my original posting. I construed your first paragraph to be that no matter how long the yellow light is, there will be idiots running red lights, of which I agree. It did not strike me that you had picked up that the yellow lights were too short by "national guideline". Again, I was not slamming you or alwaysright. I was pointing out something that I thought both of you had missed. I do agree with all of your comments in your original posting.

    Scott

  • June 9, 2008

    8:16 a.m.

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    alwaysright writes:

    Scott.

    Your right. I must have missed the part with" Engineers" in it.

    That explains everything.

  • June 9, 2008

    8:32 a.m.

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    jd writes:

    I have seen lights in Denver Metro that the yellow light is no longer than 1 second long. I have seen intersections where a vehicle traveling at the posted speed could not get across the intersection while the light was yellow and this is a small intersection. And you wonder why it's to easy to run a red light in this town. Now I've also seen the 6th car go through a red light so they can beat the other traffic. Both sides have problems, the drivers and the traffic engineers.

  • June 9, 2008

    8:50 a.m.

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    ds42 writes:

    I'm glad Denver is going to be experimenting with this radical concept of proper yellow light timings. It may take a little while for beneficial effects to be seen, though, since drivers around here have been conditioned for years that yellow means having to "slam the accelerator" or "slam the brake" to avoid running a red light.

    When I visit other cities, there's always a period of adjustment to get accustomed to normal yellow lights, and realize that I'll have enough advance warning to calmly come to a graceful stop before the light turns red. (And another period of adjustment when I return to Denver...)

  • June 9, 2008

    11:59 p.m.

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    Flatlander88 writes:

    Hook wrote:

    " ...longer yellows = more people speeding up to make it before the light turns red... more accidents."

    Baloney!

    Longer yellows = an immediate and dramatic reduction in the # of people running, with no "rebound." That is, once drivers get used to the longer yellow, they do not resume running it. The # of runners stays down, permanently. This improvement comes without having to add cameras and live with the rear end accidents that they cause.
    If you are skeptical, have a look at "Follow Up Question # 1" at this address: http://www.highwayrobbery.net/redligh...