Denver's yellow lights

Posted by suburbdweller on March 30, 2008 at 12:19 a.m. (Suggest removal)

This story brings up an astounding thing to consider!

If adding 1.5 seconds to a yellow light can reduce light violations by 94% as in the example cited in Kevin's video article, then wouldn't it be a whole lot cheaper AND more effective for the city to do that at "dangerous" intersections INSTEAD of putting up expensive red-light cameras?

If the goal is to reduce accidents, then for the city to do otherwise only proves that it's about making money---profit for the companies making and installing the cameras and revenue for the city from "fines" (a.k.a. hidden taxes)---not about safety.

Someone should check for links between the city officials involved in the camera program and the companies who stand to profit from it.

Posted by AC on March 29, 2008 at 12:25 p.m. (Suggest removal)

Kory: Kevin's analysis is correct. The standards say 3 to 6 seconds depending on speeds and other factors. It goes no higher than six seconds. You mistake "illegal activity" for "traffic engineers made the light too short." You shouldn't set the yellow light for the speed limit; you set it for what the traffic is doing if your goal is really safety and not revenue. I'm familiar with 6th and Kalamath. The curve to the left right at the end of the viaduct isn't an issue related to advance warning, it's related to the stopping capability of a car or bus or semi while its also slightly turning. The laws of physics don't get suspended just because Denver wants revenue off short-timing its lights. "Should be" obeying the speed limits is a nice refrain, but the fact is the limit may be underposted as well. That's common in Denver. The fact is, traffic signals have to adjust to the needs of traffic, not the other way around.

Posted by KoryNParker on March 29, 2008 at 7:53 a.m. (Suggest removal)

While Kevin's investigation is interesting, it would appear that his concept of "engineering shortcomings" is misapplied. The fact that the actual traffic speed on 6th Avenue is faster than the posted speed limit may be true, but that is not a logical reason to adjust the length of the yellow light. Kevin's fuzzy logic would seem to indicate that the traffic signal should be adjusted to accommodate illegal driving activity. Sure, red-light violations could be reduced by increasing the length of the yellow light cycle - but why stop at adding 1.0 or 1.5 seconds? Why not 2.0, 2.5, 3.0, heck why not 60 seconds? If the length of the yellow lights are properly set according the national standards, based upon the posted speed limit, then the efficient cycling of the lights allows for the maximum amount of green light time that is safe - thus allowing the maximum amount of traffic to lawfully flow safely through the intersection. Traffic heading southbound on Kalamath would be further restricted if the yellow light for eastbound 6th Avenue was lengthened, causing more traffic to backup - possibly interfering with the intersection at Kalamath & 8th Avenue. Kevin fails to mention the existence of conspicuous overhead warning signs facing eastbound traffic on 6th Avenue approaching Kalamath, bearing the international icon a signal light with wording of "Signal Ahead", located a significant distance west of the intersection on the 6th Avenue bridge, thus giving drivers more than adequate advance notice. Therefore, the "jog to the left" and the signal lights located further east on 6th Avenue appear to be adequately compensated by the advance warning signs. Let's face it - the lights should be certified as having the proper length of yellow lights before these cameras are activated, but drivers should be obeying the speed limit, so as to allow them the lawful reasonable opportunity to stop upon the signal light turning red - not the "Mad Tea Party" concept Kevin suggests where the illegal speeders would be setting the legal standard.