Archive for November 13th, 2009

A Link Between the Murder Rate and Traffic Fatalities?

The always interesting and prolific Michael Sivak has a new paper, “Homicide Rate as a Predictor of Traffic Fatality Rate” — a pretty self-explanatory title — just out in the journal Traffic Injury Prevention.

Here’s the details:

Background: In the United States, traffic fatality rates per distance driven vary greatly from state to state, with the maximum rate being 2.9 times the minimum rate. This study was designed to examine factors associated with this variability.

Method: A multiple regression was performed on the 2006 state data. The dependent variable was the fatality rate per distance driven. There were 10 independent variables.

Results: The analysis identified seven statistically significant factors: homicide rate per capita (used in the analysis as a proxy for aggression), physicians per capita, safety-belt usage rate, proportion of male drivers, proportion of drivers over 64 years of age, income per capita, and deaths caused by alcohol related liver failures per capita (a proxy for the extent of intoxicated driving). These seven factors accounted for 71 percent of the variance in the traffic fatality rates. The strongest predictor of the traffic fatality rate was the homicide rate.

Conclusion: This finding suggests that social aspects of human interaction may play an important role in traffic safety.

In other words, states with a high murder rate are filled with aggressive people, many of whom take it out on the roads.

One issue that pops up in my head is the validity of statewide comparisons for both driving and murder rates, for the primary reason that the places where traffic fatalities occur are not necessarily the same places where murders occur (I’m imagining that the places with the higher per capita murder rates are urban counties, where driving exposure would be much less, but I may be very wrong on this). As William Lucy has argued, for example, in the state of Virginia there was a much higher risk of leaving home in sparsely populated suburbs — not because of would-be murderers but because of driving risk. Conversely, “cities that often are considered dangerous, like Richmond and Norfolk, ranked 19th and 30th in the number of traffic and homicide-by-stranger deaths among the 49 metropolitan-area jurisdictions included in the ranking.”

Or maybe some states just have a lot of murders and a lot of traffic fatalities, with no causal link between the two. Or perhaps all the police are all working on murder investigations, and too busy for traffic enforcement (though I have suggested the two should not be viewed is isolation).

I’m also not sure how deaths by liver disease as a proxy for alcohol-related driving deaths — there would seem to be any number of other things to consider (e.g., health-care quality in a given place, or density — Manhattan is filled with heavy drinkers but certainly must have fewer drunk drivers per capita).

Posted on Friday, November 13th, 2009 at 3:51 pm by: Tom Vanderbilt
Comments Off on A Link Between the Murder Rate and Traffic Fatalities?. Click here to leave a comment.
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



November 2009

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