Archive for March 23rd, 2009

More on the Geography of Danger

This map, of bicycle crashes in Toronto, was mentioned in the comments to the original post. And then there’s Transportation Alternatives’ invaluable crash maps. Projects like this loom on the horizon. I’d be curious to know what others are out there.

The potential impact GIS (and real-time mapping) has for traffic safety (among other things) seems great, particularly as we can add sophistication to the layers: Time of day, exposure data, road characteristics, etc. Some of this requires hard coding, but I’m wondering what other information could be gleaned from mobile phones and the like. The obvious source of interest would be something like pedestrian volumes and walking speeds, as recorded by iPhones and the like; too many pedestrians moving too slowly up Fifth Avenue — extend the walk signal! But other uses can be imagined as well; “dwell time,” the amount of time pedestrians spend in public areas, could be measured, for example. Or how quickly pedestrians cross streets (this could be part of a larger Christian Nold-style “bio-mapping project” to measure particularly unpleasant intersections and the like). Vibration-sensitive PDAs could monitor potholes on streets and in bike lanes. Sensors could detect “honks” and a “honk map” could be created, with targeted police enforcement and selective traffic engineering solutions. Credit cards could be synced up with MetroCards or EZPasses to determine how much economic activity in the city each form of transportation brings. Data on red-light running from camera-equipped intersections could be fed anonymously to in-car GPS systems, as well as those on the personal devices of pedestrians. The possibilities are legion.

One of the myriad problems with mapping risk is that the numbers, particularly when exposure data is absent, can lack explanatory power. Oh, there were no pedestrians struck this year on the F.D.R. Drive — this obviously does not imply a street that is safe for pedestrians. And while I do feel, like Pascal, that most of man’s unhappiness comes from not being able to simply stay quietly in his room, one must leave the house, and overhyping everyday dangers can be its own form of danger.

An interesting phenomenon in terms of risk and the built environment is that what we perceive as risky is not always the place where the risk actually lies (and it’s an interesting question as to whether this misperception itself leads to the risk profile). An interesting study at the University of North Carolina looked at students’ perceptions of pedestrian risk on campus versus perception and found that the two did not always correlate. The study found all sorts of curious detail, as charted in the image below (which shows a relatively equal distribution of crashes but certainly not an equal distribution of risk perception); e.g., there were more crashes near places like the stadium than people believed there were (there are certain biases to be careful of; proximity to a building in general increases the reporting of crashes, which may throw off the actual risk profile).

Posted on Monday, March 23rd, 2009 at 5:50 pm by: Tom Vanderbilt
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Passive Resistance

David Alpert taps into an annoyance of mine, that staple of car crash reporting known as the passive voice.

He notes a Washington Post story from yesterday:

Four people ranging in age from 19 to 21 were killed early yesterday in Culpeper County, Va., when their car collided with a vehicle that was going the wrong way, Virginia State Police said.

As he notes, until we get to full DARPA-style automation, the sense of agency cannot be attributed entirely to the car (particularly in this case, as cars don’t choose to go down the wrong way down roads). But we seem to, and one wonders hows this plays into our cultural downgrading of personal responsibility when it comes to negligent driving.

Finally, our habit of dehumanizing the actions of cars tends to create assumptions that their actions are not actually someone’s responsibility. A driver hit and killed some people in another car in Culpeper. It’s extremely unlikely his car magically malfunctioned. And even if it did, we don’t engage in the same linguistic contortions to say, for example, that a police officer’s bullet impacted a suspected robber, who had themselves been holding a gun which fired into someone else earlier in the day. That would be silly. So is this.

This writer was in agreement.

Posted on Monday, March 23rd, 2009 at 2:31 pm by: Tom Vanderbilt
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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.

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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



March 2009

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