Flashing Signal Justification?

[joengr]

Hello,

Does anyone know of a traffic study done on the basis of justifying a flashing intersection signal (Major Lane flashing yellow, Minor thorough fare flashing red) instead of using a regular red-yellow-green signal? Everywhere I look directs me to MUTCD which leaves it up to either engineering judgement or traffic study. What would be the defining criteria of this study? I need something somewhat concrete to put in the hands of my boss (city council) to justify either installing beacons or leaving the original signal.

 

[bimr]

Intersection Control Beacons may be used at intersections where traffic or physical conditions do not justify conventional traffic control signals but crash rates indicate the possibility of a special need.

http://mutcd.fhwa.dot.gov/htm/2003r1/part4/part4k.htm

 

[ACtrafficengr]

Here's arather dated report from the NY State DoT on the subject. It might still be of use.

With modern actuation, I prefer to have the side road rest in red. It doesn't add much delay, and cuts the risk of angled crashes.

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

 

[msquared48]

Perspmally, I'd like to flash a lot of those red light cameras...

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[dik]

Mike... you may be able to.

Many of the cameras are sensitive to a part of the infrared spectrum and it's possible to make a slave strobe that can overexpose the picture caused by the initial flash.

Dik

 

[msquared48]

Verrrrrryyyy intersting! And my brother-in-law is an EE!

How cool is that!

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[LordUlrich]

My approach would be to verify warrants for a signal, 2-way stop and 4-way stop (all in the MUTCD) One modification I would make it checking the warrants for the daylight hours, and the overnight separately. A lot of the signals in my area go to a flashing arrangement (yellow on major, red on minor) after about 10PM, as the volumes are next to nothing overnight and a 2-way stop would be adequate.
If signal warrants are not met for the overnight you could go to a flash, but if the warrants are met running on a typical green-yellow-red arrangement would be justified.
Additionally if the 4-way stop warrants are met(but not signal) then running all way red flashing or with green-yellow-red is probably better.

 

[ACtrafficengr]

"And my brother-in-law is an EE!"

Sounds like a hereditary problem.

I have to paint myself with the same brush. My father was a structural PE, and my 4 year old says he wants to be an engineer, too. Sorry if I caused any offense.



"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928