Browsing by Subject "Travel time reliability"

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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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    Value of reliability: actual commute experience revealed preference approach.
    (2010-07) Carrion, Carlos
    This research investigates the value placed by travelers on HOT lanes because of improvements in travel time reliability. This value depends on how the travelers regard a route with predictable travel times (or small travel time variability) in comparison to another with unpredictable travel times (or high travel time variability). For this purpose, commuters were recruited and equipped with Global Positioning System (GPS) devices and instructed to commute for two weeks on each of three plausible alternatives between their home in the western suburbs of Minneapolis eastbound to work in downtown or the University of Minnesota: I-394 HOT lanes, I-394 General Purpose lanes (untolled), and signalized arterials close to the I-394 corridor. They were then given the opportunity to travel on their preferred route after experiencing each alternative. This revealed preference data was then analyzed using mixed logit route choice models. Three measures of reliability were explored and incorporated in the estimation of the models: standard deviation (a classical measure in the research literature); shortened right range (typically found in departure time choice models); and interquartile range (75th - 25th percentile). Each of these measures represents distinct ways about how travelers deal with different sections of reliability. In all the models, it was found that reliability was valued highly (and statistically significantly), but differently according to how it was defined. The estimated value of reliability in each of the models indicates that commuters are willing to pay a fee for a reliable route depending on how they value their reliability savings. Furthermore, a meta-analysis is performed in order to explain the differences across valuation ratio estimates across studies. The results indicate differences are significant across regions, choice dimension (e.g. mode choice), travel time unit (e.g. data collected at AM or PM), and year of study.