Incorporation of Travel Time Reliability in Regional Travel Model

2018 ◽  
Vol 2672 (49) ◽  
pp. 46-57 ◽  
Author(s):  
Surabhi Gupta ◽  
Peter Vovsha ◽  
Arup Dutta ◽  
Vladimir Livshits ◽  
Wang Zhang ◽  
...  
Keyword(s):  
Travel Time ◽  
Partial Correlation ◽  
Practical Method ◽  
Vehicle Speed ◽  
Travel Time Reliability ◽  
Reliability Measures ◽  
The Third ◽  
The Core ◽  
Sensitivity Tests ◽  
Fourth Step

The paper presents a practical method for incorporation of travel time reliability in a regional travel model. The discussion includes five consecutive steps. First it describes how the vehicle speed dataset for the metropolitan area of Phoenix, AZ, termed HERE, was processed and link-level volume–delay–reliability functions were estimated, and then how link-level reliability measures can be applied for network path building. The third step describes how trip origin–destination (OD) reliability measures can be constructed out of the link-level reliability measures. The fourth step involves implementation of the link-level and OD-level reliability measures in highway assignment, mode choice, and other travel models. The fifth step includes model validation and sensitivity tests. The paper addresses several long-standing issues associated with incorporation of travel time reliability in operational travel models in practice. These issues include construction of OD reliability measures with the recognition that the core link-level reliability measures such as standard deviation or variance are not additive in a general case, accounting for a partial correlation between travel time distributions for different links, and incorporation of travel time reliability in a standard static assignment.

Travel Time Reliability Measures Accommodating Scheduling Preferences of Travelers

2019 ◽  
Vol 2673 (4) ◽  
pp. 708-721 ◽  
Author(s):  
Mojtaba Rajabi-Bahaabadi ◽  
Afshin Shariat-Mohaymany ◽  
Shu Yang
Keyword(s):  
Travel Time ◽  
Time Distribution ◽  
Travel Time Reliability ◽  
Time Data ◽  
Reliability Measures ◽  
Time Performance ◽  
Early Arrival ◽  
Travel Time Distribution ◽  
Travel Time Data ◽  
Schedule Adherence

Existing travel time reliability measures fail to accommodate scheduling preferences of travelers and cannot distinguish between the variability associated with early and late arrivals. This study introduces two new travel time reliability measures based on concepts from behavioral economics. The first proposed measure is an indicator of the width of travel time distribution. It considers scheduling preferences of travelers and can distinguish between early arrival and late arrival. The second measure determines the skewness of travel time distribution. To estimate the proposed measures, travel time is modeled by mixture models and closed-form expressions are derived for the expected values of early and late arrivals. In addition, real travel time data from a freeway segment is used to compare the proposed measures with the existing travel time reliability measures. The results suggest that, although there exist significant correlations between travel time reliability measures, travelers’ preferences have considerable effects on the travel time reliability as perceived by them. Furthermore, four measures are developed based on the notions of early and late arrivals to assess the on-time performance (schedule adherence) of transit vehicles at stop level. The results of this study show that the four measures can serve as complementary to the existing on-time performance indices.

Traffic and Transit Travel Time Reliability Indexes and Confidence Intervals

2017 ◽  
Vol 2649 (1) ◽  
pp. 28-41 ◽  
Author(s):  
Travis B. Glick ◽  
Miguel A. Figliozzi
Keyword(s):  
Travel Time ◽  
Confidence Intervals ◽  
Time Variability ◽  
Travel Time Reliability ◽  
Reliability Measures ◽  
Time Space ◽  
Estimate Travel Time ◽  
Low Performance ◽  
Transit Reliability ◽  
Travel Time Variability

As congestion worsens, the importance of rigorous methodologies to estimate travel time reliability increases. Exploiting fine-granularity transit GPS data, this research proposes a novel method to estimate travel time percentiles and confidence intervals. Novel transit reliability measures based on travel time percentiles are proposed to identify and rank low-performance hot spots; the proposed reliability measures can be utilized to distinguish peak-hour low performance from whole-day low performance. As a case study, the methodology is applied to a bus transit corridor in Portland, Oregon. Time–space speed profiles, heat maps, and visualizations are employed to highlight sections and intersections with high travel time variability and low transit performance. Segment and intersection travel time reliability are contrasted against analytical delay formulas at intersections—with positive results. If bus stop delays are removed, this methodology can also be applied to estimate regular traffic travel time variability.

Empirical Analysis of Travel Time Reliability Measures in Hanshin Expressway Network

2009 ◽  
Vol 13 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Akito Higatani ◽  
Toshihiko Kitazawa ◽  
Jun Tanabe ◽  
Yoshiki Suga ◽  
Ravi Sekhar ◽  
...  
Keyword(s):  
Travel Time ◽  
Empirical Analysis ◽  
Travel Time Reliability ◽  
Reliability Measures

scholarly journals Measures of Functional Reliability of Two-Lane Highways

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4577
Author(s):  
Krzysztof Ostrowski ◽  
Marcin Budzynski
Keyword(s):  
Travel Time ◽  
Cross Sections ◽  
High Speed ◽  
Travel Speed ◽  
Traffic Volume ◽  
Traffic Density ◽  
Travel Time Reliability ◽  
Reliability Measures ◽  
Long Distance ◽  
Technical Parameters

Rural two-lane highways are the most common road type both in Poland and globally. In terms of kilometres, their length is by far greater than that of motorways and expressways. They are roads of one carriageway for each direction, which makes the overtaking of slower vehicles possible only when there is a gap in the stream of traffic moving from the opposite direction. Motorways and express roads are dual carriageways that are expected to support high speed travel mainly over long distances. Express roads have somewhat lower technical parameters and a lower speed limit than motorways. Two-lane highways are used for both short- and long-distance travel. The paper presents selected studies conducted in Poland in 2016–2018 on rural two-lane highways and focuses on the context of the need for their reliability. The research was carried out on selected short and [longer road sections located in various surroundings, grouped in terms of curvature change rate CCR, longitudinal slopes and cross-sections (width of lanes and shoulders). The studies of traffic volumes, travel time and travel speed, as well as traffic density, will be used to analyze traffic performance and identify measures of travel time reliability. The analyzed roads were characterized by good technical parameters and significant variability of traffic volume throughout the day, week and year. Some roads experience congestion, i.e., situations in which traffic volume Q is close to or above respective road capacity C. In order to determine the form of the suitable reliability measures, it will be important to determine the extent to which a road’s geometric and traffic characteristics impact travel speed and time. The paper presents well-known reliability measures for dual carriageways and proposes new measures, along with an evaluation of their usefulness in the assessment of the functioning of two-lane highways.

Performance Measures to Characterize Corridor Travel Time Delay Based on Probe Vehicle Data

2015 ◽  
Vol 2526 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Thomas M. Brennan ◽  
Stephen M. Remias ◽  
Lucas Manili
Keyword(s):  
Travel Time ◽  
Performance Measures ◽  
The United States ◽  
Flow Speed ◽  
Performance Measure ◽  
Vehicle Speed ◽  
Travel Time Reliability ◽  
Highway Capacity Manual ◽  
Probe Vehicle ◽  
Vehicle Data

Anonymous probe vehicle data are being collected on roadways throughout the United States. These data are incorporated into local and statewide mobility reports to measure the performance of highways and arterial systems. Predefined spatially located segments, known as traffic message channels (TMCs), are spatially and temporally joined with probe vehicle speed data. Through the analysis of these data, transportation agencies have been developing agencywide travel time performance measures. One widely accepted performance measure is travel time reliability, which is calculated along a series of TMCs. When reliable travel times are not achieved because of incidents and recurring congestion, it is desirable to understand the time and the location of these occurrences so that the corridor can be proactively managed. This research emphasizes a visually intuitive methodology that aggregates a series of TMC segments based on a cursory review of congestion hotspots within a corridor. Instead of a fixed congestion speed threshold, each TMC is assigned a congestion threshold based on the 70th percentile of the 15-min average speeds between 02:00 and 06:00. An analysis of approximately 90 million speed records collected in 2013 along I-80 in northern New Jersey was performed for this project. Travel time inflation, the time exceeding the expected travel time at 70% of measured free-flow speed, was used to evaluate each of the 166 directional TMC segments along 70 mi of I-80. This performance measure accounts for speed variability caused by roadway geometry and other Highway Capacity Manual speed-reducing friction factors associated with each TMC.

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