Recently in nexus Category

Continuing on where are they now:

Nexus group alumnus Ning Li and Nexus group alumna, Wenling Chen, his wife, both work for Virginia DOT and are proud parents of 7 month old Jay. Ning was just selected by the National Safety Council as a Rising Star of Safety, one of the few in transportation. This is the second major safety award Ning has won.

The reason given was:

“In an effort to develop strategies for reducing Virginia’s roadway departure crashes, Ning identified and addressed a major defect in Virginia’s RD [Roadway Departure] crash data. Through collaboration with national peers, Ning verified the national scope of the defect and brought the issue to the attention of the Federal Highway Administration. As a result, FHWA released an official memorandum in 2009 on a new RD crash definition and criteria. Not only were Ning’s suggestions adopted in the memo, FHWA staff also acknowledged his ‘significant contributions to the important highway safety effort.’”

Nexus group research will be presented at the Transportation Research Board conference in Washington DC, next week. Details of sessions are below, along with links to the papers:

Recently published:

• 
  

  Zhang, Lei (2010) Do Freeway Traffic Management Strategies Exacerbate Urban Sprawl? The Case of Ramp Metering Transportation Research Record: Journal of the Transportation Research Board. #2174 pp.99-109.
  

Abstract

The impact of highway capacity expansion on urban land use has been studied extensively. With the shift of transportation investment priorities from major capacity expansion projects to operational improvements, it has become increasingly important to understand the impact of transportation control measures such as traffic management and pricing on location choices. This paper explores the impact of traffic management strategies on land use patterns using the example of ramp metering. A regression-based transportation model is employed to capture changes in accessibility due to ramp metering on a highway network. A land use change indicator model then estimates how employment and residential density distributions shift in response to changing accessibility in several stylized urban areas with various initial land use patterns (e.g., monocentric and polycentric cities). Ramp metering is shown to improve accessibility in a nonuniform fashion. The resulting land use changes depend on the existing land use conditions. In monocentric cities, ramp metering exacerbates urban sprawl by encouraging residents to live further away from their workplaces, which produces avoidable excess travel. In polycentric cities with both nondominant central business districts and secondary employment centers, ramp metering actually encourages residents to relocate to areas near existing employment centers and therefore serves as an antisprawl measure. The weakest impact of ramp metering on land use is observed when an urban area has a perfect job-housing balance. Other interesting findings suggest that by making downtown areas more accessible, ramp metering may help revitalize declining city centers in congested cities and that business location decisions are not significantly affected by ramp metering.

The first version of this paper was written by Lei as a term paper for one of my classes (I think PA8202: Networks and Places). Unfortunately it is behind a paywall (TRR should be set free, just as other National Academies publications have been), though I am sure the author will happily share a copy.

Congratulations to University of Minnesota Civil Engineering and Nexus Group Alumnus Ning Li (now Senior Highway Safety Engineer, Virginia Department of Transportation, Richmond, Virginia) for receiving the ITE
Past Presidents' Award for Merit in Transportation Engineering in recognition of the paper titled "Improving Data Accuracy of Roadway Departure Crashes: Virginia Practice and its National Implications."