Red Yellow Green

In Traffic I make a passing mention of the evolution of traffic light sequences:

Others wanted the yellow light shown before the signal was changing to red and before it was changing from red back to green (which one sees today in Denmark, among other places, but nowhere in North America).

Reader Claire writes in to note that she remembers this sequence being used in the U.S.:

I distinctly remember passing through signals of this type on arterial streets in Chicago between 1977 – 1983. They were mostly located west of the L tracks on arterial streets like Belmont, Armitage, Fullerton, Devon, and Ashland.

Now, I didn’t say they were never used in the U.S., just that they aren’t anymore — although I may be wrong here and I’d be curious to see an example. She helpfully points us to Willis Lamm’s Traffic Signal page, which contains video examples of these “really funky signal phases.”

I’ve seen international studies on the potential problems with the red-amber-green phase, but haven’t really heard or read an account of why these phases vanished in the U.S. (though I’m sure the information is out there, in some back issue of the ITE Journal). I can imagine there are pedestrian issues, not to mention intersection clearance issues. And given that hardly anyone drives a manual shift in the U.S., one of the perceived virtues of that system is now largely lost here, like an old piece of slang no one uses anymore.

This entry was posted on Tuesday, July 14th, 2009 at 12:01 pm and is filed under Traffic Engineering, Traffic Gadgets, Traffic Signals, Traffic Wonkery. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

9 Responses to “Red Yellow Green”

  1. chrismealy Says:

    I think they have them in Vancouver BC.

  2. Rich Wilson Says:

    In Russia, it seemed to me that the Red+Yellow preceding the Green was a signal to the drivers to put it in gear and gun their engines, the sound of which alerted pedestrians to get the hell out of the way. I remember being terrified at the site of a babooshka hobbling as fast as she could with her stuffed grocery bags to get out of the way before the cars came storming through. I’m not so sure they would have waited.

    I’ve never seen anything but green-yellow-red-green in Vancouver, but I haven’t been there in 10 years.

  3. Eric Fischer Says:

    I remember a red+yellow crossing of the Midway Plaisance in Chicago in the 1990s, perhaps on Woodlawn? It was gone when I checked earlier this year, though.

  4. Bossi Says:

    I’ve seen the amber prior to red is used in Montréal, among some other places at least in Québec.

  5. Bossi Says:

    er… that is, amber prior to green. Sleep deprivation is a bit of a theme this week.

  6. Frank Eggers Says:

    When I was a kid visiting suburban Baltimore in 1947, the amber light was lit before green. I wish they did that now, especially because I am one of those eccentric nuts who has a manual transmission in my car. Knowing when the green will come on would give me time to shift from neutral to low. How, I have to watch the light for the cross traffic.

    On a slightly different note, probably a manual transmission is safer than an automatic transmission. Sometimes an accident occurs when a driver hits the accelerator instead of the brake. Under those low speed conditions, with a manual transmission, probably the driver would have his left foot on the clutch so, if he hit the accelerator instead of the brake with his right foot, little would happen. Unfortunately, I have been unable to find research on this.

  7. Lee Says:

    I remember seeing yellow before green in Montréal or Québec, maybe 15+ years ago. I was told that it was a cue for everyone to get in-gear so everyone was ready to go at the same time. Also, it was a cue for anyone crossing the street to start running for the sidewalk. After seeing that I couldn’t understand why we didn’t have that here.

  8. RealPerson Says:

    I for one use a manual transmission! Facts: Manual transmission gives you more control over the rpm of the engine, manual transmissions have better gas mileage, manual transmissions make you think about how you are driving.
    I however do not need a 2 second yellow light to tell me to switch from stop/neutral into 1st.
    I do need a sign on my rear end that says PUT YOUR FOOT ON THE BRAKE
    and another one that pops out when I am on a hill that says STAY 10 FEET AWAY because my car WILL roll backward into the fool who (in an automatic vehicle) releases their foot off of the brake pedal.

  9. fred_dot_u Says:

    As one of those famous redneck comedians says, “Here’s your sign”

Leave a Reply

Traffic Tom Vanderbilt

How We Drive is the companion blog to Tom Vanderbilt’s New York Times bestselling book, Traffic: Why We Drive the Way We Do (and What It Says About Us), published by Alfred A. Knopf in the U.S. and Canada, Penguin in the U.K, and in languages other than English by a number of other fine publishers worldwide.

Please send tips, news, research papers, links, photos (bad road signs, outrageous bumper stickers, spectacularly awful acts of driving or parking or anything traffic-related), or ideas for my Transport column to me at:

For publicity inquiries, please contact Kate Runde at Vintage:

For editorial inquiries, please contact Zoe Pagnamenta at The Zoe Pagnamenta Agency:

For speaking engagement inquiries, please contact
Kim Thornton at the Random House Speakers Bureau:

Order Traffic from:

Amazon | B&N | Borders
Random House | Powell’s

U.S. Paperback UK Paperback
Traffic UK
Drive-on-the-left types can order the book from

For UK publicity enquiries please contact Rosie Glaisher at Penguin.

Upcoming Talks

April 9, 2008.
California Office of Traffic Safety Summit
San Francisco, CA.

May 19, 2009
University of Minnesota Center for Transportation Studies
Bloomington, MN

June 23, 2009
Driving Assessment 2009
Big Sky, Montana

June 26, 2009
PRI World Congress
Rotterdam, The Netherlands

June 27, 2009
Day of Architecture
Utrecht, The Netherlands

July 13, 2009
Association of Transportation Safety Information Professionals (ATSIP)
Phoenix, AZ.

August 12-14
Texas Department of Transportation “Save a Life Summit”
San Antonio, Texas

September 2, 2009
Governors Highway Safety Association Annual Meeting
Savannah, Georgia

September 11, 2009
Oregon Transportation Summit
Portland, Oregon

October 8
Honda R&D Americas
Raymond, Ohio

October 10-11
INFORMS Roundtable
San Diego, CA

October 21, 2009
California State University-San Bernardino, Leonard Transportation Center
San Bernardino, CA

November 5
Southern New England Planning Association Planning Conference
Uncasville, Connecticut

January 6
Texas Transportation Forum
Austin, TX

January 19
Yale University
(with Donald Shoup; details to come)

Monday, February 22
Yale University School of Architecture
Eero Saarinen Lecture

Friday, March 19
University of Delaware
Delaware Center for Transportation

April 5-7
University of Utah
Salt Lake City
McMurrin Lectureship

April 19
International Bridge, Tunnel and Turnpike Association (Organization Management Workshop)
Austin, Texas

Monday, April 26
Edmonton Traffic Safety Conference
Edmonton, Canada

Monday, June 7
Canadian Association of Road Safety Professionals
Niagara Falls, Ontario

Wednesday, July 6
Fondo de Prevención Vial
Bogotá, Colombia

Tuesday, August 31
Royal Automobile Club
Perth, Australia

Wednesday, September 1
Australasian Road Safety Conference
Canberra, Australia

Wednesday, September 22

Wisconsin Department of Transportation’s
Traffic Incident Management Enhancement Program
Statewide Conference
Wisconsin Dells, WI

Wednesday, October 20
Rutgers University
Center for Advanced Infrastructure and Transportation
Piscataway, NJ

Tuesday, March 8, 2011
Ontario Injury Prevention Resource Centre
Injury Prevention Forum

Monday, May 2
Idaho Public Driver Education Conference
Boise, Idaho

Tuesday, June 2, 2011
California Association of Cities
Costa Mesa, California

Sunday, August 21, 2011
American Association of Motor Vehicle Administrators
Milwaukee, Wisconsin

Wednesday, October 26, 2011
Attitudes: Iniciativa Social de Audi
Madrid, Spain

April 16, 2012
Institute for Sensible Transport Seminar
Gardens Theatre, QUT
Brisbane, Australia

April 17, 2012
Institute for Sensible Transport Seminar
Centennial Plaza, Sydney
Sydney, Australia

April 19, 2012
Institute for Sensible Transport Seminar
Melbourne Town Hall
Melbourne, Australia

January 30, 2013
University of Minnesota City Engineers Association Meeting
Minneapolis, MN

January 31, 2013
Metropolis and Mobile Life
School of Architecture, University of Toronto

February 22, 2013
ISL Engineering
Edmonton, Canada

March 1, 2013
Australian Road Summit
Melbourne, Australia

May 8, 2013
New York State Association of
Transportation Engineers
Rochester, NY

August 18, 2013 “Ingenuity” Conference
San Francisco, CA

September 26, 2013
TransComm 2013
(Meeting of American Association
of State Highway and Transportation
Officials’ Subcommittee on Transportation
Grand Rapids MI



July 2009
« Jun   Aug »

No, you probably won be compensated one million dollars; however, with the right blend of negotiating skills and patience, your efforts will be substantially rewarded!I have seen up to forty thousand dollars added to starting compensation through diligent negotiations. It is a way to significantly raise your standard of living and sense of self, simply by