Is the ‘Michigan Left’ Right for America?

Left turns at intersections are the bane of traffic. They impede traffic flow (a “protected” green arrow holds up the majority of the intersection for a minority of drivers), UPS drivers’ routes are programmed to avoid them, and they’re dangerous for drivers (who often have trouble judging the speed of oncoming drivers, or have their view obstructed in determining whether it’s safe to cross) — not to mention pedestrians, who typically have the “Walk” signal when cars have a left-turn signal (and, because of the aforementioned problems, cars may only be paying attention to pedestrians at the very last moment).

Yesterday, John J. Miller asked me about a regional specialty in the world of traffic, the so-called “Michigan left.” Having spent some time in the environs of the Motor City, I had a passing familiarity with the system, but had sort of filed it away in my brain — and didn’t bring it up in the book. But he raised a very good point: Why isn’t it used elsewhere?

The Michigan left (not to be confused with the “Pittsburgh left”), or the “median U-turn crossover,” is what the Federal Highway Administration, in engineering logo, would call an “alternative intersection treatment.” It originated a few decades ago in response to rising traffic volumes, particularly on suburban arterials. Basically, it seeks to remove that dangerous, traffic-slowing left-turn from the main intersection by having drivers who wish to turn left as they approach an intersection first make a right turn, drive a short ways, then make a u-turn via a short bay, and then head in their desired direction, back through the original intersection.

It looks a little something like this (illustration courtesy of

If you’re still confused, there’s a nice Flash animation by the Michigan DOT here. MDOT goes on to say that the treatments provide “20 to 50 percent greater capacity than direct left-turns” and, on roads with Michigan lefts, crashes have been reduced “30 to 60 percent overall.”

The only problems I can see with the Michigan left is 1.) You need adequate space for dividing medians (which have a further benefit in reducing head-on crashes) and 2.) Drivers tend to find them a bit confusing and counterintuitive — why should I have to turn right to turn left?

The FHWA also opines that they should only be used in places where left-turning traffic is a relative minority of traffic: “Locations with high left-turning volumes may not be good candidates because the out-of-direction travel incurred and the potential for queue spill back at the median U-turn location could outweigh the benefits associated with removing left-turns from the main intersection.”

The Michigan left is not limited to Michigan. North Carolina has been giving them a spin, while New Jersey-ians of course have the related “Jersey Jughandle.” (I’ll save its intricacies for another post). Then there’s CFIs (ditto). The strangest approach to the left-turn, over-saturated intersection problem I’ve seen recently was on the approach to Sanibel Island, Fla., from Fort Myers, at the intersection of Summerlin and San Carlos: A huge, ghastly, looming “flyover,” which seemed horribly out of place amidst the flat sprawl (a few businesses have been literally lost in its shadows).

But, from what I can tell, the “Michigan left” essentially remains a regional specialty, the traffic equivalent of the state’s sour cherries. What do you say, America, are you ready for the Michigan left at an intersection near you?

ADDENDUM: The reader in the comments below rightfully asked about roundabouts, which are of course superior in both safety and flow to conventional signalized intersections — up to a certain traffic flow (after which they lose effectiveness) and when space permits. I should have qualified the whole discussion by positing Michigan lefts as a superior alternative to “conventional signalized intersections.”

This entry was posted on Wednesday, July 9th, 2008 at 2:20 pm and is filed under Drivers, Traffic Culture, Traffic Engineering, Traffic Wonkery. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

Comments are closed.

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 2008

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