Portland State University

When engineers focus on transportation systems, they often produce brilliant solutions. Sometimes, however, they focus in the wrong place.

 “Engineers are really good; if you tell them, ‘This is what we want to accomplish,’ they’ll do it,” said Peter Jacobsen, himself an engineer and a public health consultant. “But traffic safety hasn’t had a good scientific, evidence-based approach that we have in, say, nuclear-power-plant design.”

Jacobsen, Portland State University’s first visiting scholar this school year, will present the Vision Zero concept at Friday’s transportation seminar. Vision Zero resets the goal of transportation systems from reducing total crashes to eliminating fatalities.

“The way engineers currently look at the road system is to look at crashes,” Jacobsen said. “Vision Zero folks say to look at health: not to have fatalities or permanent disabling injuries.”

Designing for health means respecting the limits of the human body. If crossing into oncoming traffic could produce head-on collisions with a greater force than people could survive, then Vision Zero says to separate that traffic. Roundabouts reduce the likelihood of dangerous side-impact collisions.

Vision Zero could have the largest effect closer to home. Jacobsen has pushed for colleagues to consider traffic from a child’s perspective. A residential street that might be...

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The LCN+ Project Management team are responsible for improving conditions for cycling on a 900-kilometre network of London’s key commuter roads, in line with the Mayor of London’s Cycling Action Plan.

With the initial target of achieving a 200% increase in the number of cyclists in London already surpassed, the project aims to build on this by continuing to advise the 33 London boroughs on how to improve cycling infrastructure on their roads. By effectively liasing with major stakeholders such as local cycling groups, Borough Cycling Officers and Transport for London, the project can ensure that all will have agreed on the solutions reached.

Steve Cardno: Steve is the Project Manager for the London Cycle Network Plus (LCN+) project, with responsibility for the overall project management of this London wide cycling project. The LCN+ project aims to deliver 900km of high quality strategic cycle routes across London by the end of 2009/10. The project is funded by Transport for London (TfL), project managed by Camden Consultancy Services and delivered in partnership with TfL, CCS, the 33 London Boroughs and cycle user...

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Classic highway traffic flow theory can explain the evolution of signals and waves once they form. Given sufficient boundary conditions the theory captures the evolution of the traffic state over space and time. But one rarely finds such ideal boundaries on real highways. Often disturbances arise within a region that classic theory would tell us should be homogeneous. These disturbances often grow and give rise to unstable traffic upstream, e.g., resulting in stop-and-go conditions during congestion with an increased frequency of accidents. This talk will examine one potential source of these disturbances, namely the fact that after a lane change maneuver drivers accommodate an entering vehicle quicker than a departing vehicle (mandatory accommodation versus discretionary accommodation). After illustrating this imbalance on two facilities, the talk will explain how it can give rise to lasting disturbances.

Dr. Coifman is an associate professor at the Ohio State University with a joint appointment in the department of Civil and Environmental Engineering and Geodetic Science and the Department of Electrical Engineering. His research emphasizes extracting more information about traffic flow both from conventional vehicle detectors and emerging sensor technologies. His work has been recognized by the ITS America Award for The Best ITS Research and an NSF CAREER award. Dr. Coifman...

By Jennifer Dill, Ph.D.
Professor, Urban Studies & Planning 
Director, TREC

This week I’m at the International Travel Survey Conference in Australia. The conference happens every three years, attracting over 100 geeky people who spend time thinking about things like stated preference experiments, smartphone data collection, combining sampling frames, and respondent burden. I presented some work from our five city Green Lanes project, comparing our survey data with “objective” measures, such as videos and traffic counts. The focus was on intersections, where the protected lane is no longer separated from motor vehicles. An example of one design used in Portland, OR is shown in the adjacent figure.

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Some of the comparisons...