Browsing by Subject "Freeway operations"

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    Estimation of Metro Freeway System Reliability and Resilience
    (Minnesota Department of Transportation, 2022-02) Kwon, Eil; Jurrens, Chet; Wright, Cole; Mahmud, Asif
    This study has estimated and analyzed the travel-time reliability and traffic-flow performance trends of the freeway corridors in the Twin Cities metro area of Minnesota. First, TeTRES (Travel-Time Reliability Estimation System), developed in the previous study, was enhanced by adding the estimation module of the traffic-flow performance measures for selected routes. Next, the TeTRES database was populated with the external-operating condition data collected from 2010 to 2020. The enhanced TeTRES was then applied to a total of 48 directional corridors in the metro freeway network and the travel-time reliability for each corridor under different operating conditions was estimated and analyzed along with the traffic-flow performance measures for 2016-2020 period. In particular, a newly developed vulnerability index, which combines 95th percentile buffer index and 95th percentile travel rate of each route, was applied to determine yearly-reliability trends under different operating conditions for each corridor. The vulnerability index was also applied to identify the most vulnerable bottleneck section within each directional corridor using the 2019 data under all conditions. Finally, a preliminary study to assess the operational resilience of freeway corridors was conducted in this study by formulating the corridor-wide operational resilience with data from a total of six directional corridor routes in the metro freeway network.
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    Travel Time Variability After A Shock: The Case Of The Twin Cities Ramp Meter Shut Off
    (Pergamon, 2001) Levinson, David M; Zhang, Lei
    Ramp meters in the Twin Cities were turned off for 8 weeks in the Fall of 2000. This paper analyzes traffic data collected in this experiment on travel time variability with and without ramp metering for several representative freeways during the afternoon peak period. Travel time variability is generally reduced with metering. However, it is found that ramp meters are particularly helpful for long trips relative to short trips. The annual benefits from reducing travel time variability with meters are estimated to be $33.1 million, compared to the annual ramp metering costs of $2.6 million in the Twin Cities metro area. Thus, the impact on travel time variability should be captured in future ramp metering benefit/cost analysis.