"Impact of Freeway Geometric Design on Congestion Characteristics"
Congratulations to Dr. Jorge Laval, assistant professor in the School of Civil and Environmental Engineering, for earning a 2011 Faculty Early Development (CAREER) award from the National 
Science Foundation (NSF). Dr. Laval's project has been awarded $400,000.00 to investigate the various impacts of freeway geometric design on congestion characteristics.
The overall objective of Dr. Laval's research proposal is to establish the relationship between freeway design elements, such as grade and curvature, and traffic congestion characteristics, such as frequency of stop-and-go motions, hysteresis and capacity drop. His research approach is based on empirical data analysis, both existing and collected as part of the project. In particular, vehicle trajectory data will be used to correlate congestion characteristics and individual driver behavior using a combination of numerical simulation and statistical analysis. According the Laval, this approach will allow his team to unveil the link between driver behavior and freeway design, and to propose and validate a car-following theory able to capture the findings in the research.
"If successful, the results of this research will lead to improved freeway design guidelines, which currently mostly focus on providing adequate capacity. This research goes one step further to unveil the cause-effect relationships between freeway design and the characteristics of congestion once this capacity is surpassed," states Laval.
Ultimately, the research will provide answers to questions such as: "How should we design freeways so that, when there is congestion, (i) the number of acceleration/deceleration maneuvers is minimized?, or (ii) the bottleneck discharge rate is maximized?, or (iii) the number of lane-changes is minimized?" In turn, these answers will help minimizing greenhouse gases, commuter delays and accidents, respectively, and will promote a more sustainable infrastructure system in the future.
The research will also provide practitioners and researchers with arguably the first traffic flow model capable of capturing complex congestion phenomena as observed empirically. It will improve the accuracy of existing freeway infrastructure project simulation-based assessments, and allow testing of more efficient congestion control strategies that focus on minimizing emission levels, delays and accidents.
The NSF CAREER program is a Foundation-wide activity that offers the National Science Foundation's most prestigious awards in support of junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research within the context of the mission of their organizations. Such activities should build a firm foundation for a lifetime of leadership in integrating education and research. NSF encourages submission of CAREER proposals from junior faculty members at all CAREER-eligible organizations with particular emphasis on women, members of underrepresented minority groups, and persons with disabilities. For additional information about the NSF CAREER program, visit: http://www.nsf.gov/funding/pgm_summ.jsp?pims_id=503214.