Value of Travel Time Reliability in Transportation Decision Making: Proof of Conceptâ€"Maryland

Sadabadi, Kaveh Farokhi; Jacobs, Thomas; Erdoğan, Sevgi; Ducca, Frederick W; Zhang, Lei

doi:10.17226/22280

Cited by 5 publications

(5 citation statements)

References 35 publications

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“…Additional examples illustrating the value of travel time reliability can be found in Carrion and Levinson's study (3) and a report by Sadabadi et al (4).…”

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confidence: 92%

Mixture Models for Fitting Freeway Travel Time Distributions and Measuring Travel Time Reliability

Yang

2016

Transportation Research Record: Journal of the Transportation R

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Travel time reliability has attracted increasing attention in recent years and is often listed as a major roadway performance and service quality measure for traffic engineers and travelers. Measuring travel time reliability is the first step toward improving it, ensuring on-time arrivals, and reducing travel costs. Most measures of travel time reliability derive from continuous probability distributions and apply to traffic data directly. However, little previous research shows a consensus for selection of a probability distribution family for travel time reliability. Different probability distribution families could yield different values for the same measure of travel time reliability (e.g., standard deviation). The authors believe that specific selection of probability distribution families has few effects on measuring travel time reliability. Therefore, they proposed two hypotheses for accurately measuring travel time reliability and designed an experiment to prove the two hypotheses. The first hypothesis was proved by ( a) conducting the Kolmogorov–Smirnov test and ( b) checking log likelihoods and the convergences of the corrected Akaike information criterion and of the Bayesian information criterion. The second hypothesis was proved by examining both moment- and percentile-based measures of travel time reliability. The results from testing the two hypotheses suggest that ( a) underfitting may cause disagreement in distribution selection, ( b) travel time can be precisely fitted by using mixture models with a higher value of K (regardless of distribution family), and ( c) measures of travel time reliability are insensitive to the selection of the distribution family. These findings allow researchers and practitioners to avoid testing of various distributions, and travel time reliability can be more accurately measured by using mixture models because of the higher values of log likelihoods.

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“…Additional examples illustrating the value of travel time reliability can be found in Carrion and Levinson's study (3) and a report by Sadabadi et al (4).…”

mentioning

confidence: 92%

Mixture Models for Fitting Freeway Travel Time Distributions and Measuring Travel Time Reliability

Yang

2016

Transportation Research Record: Journal of the Transportation R

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“…Rafferty presents alternative applications of the NPMRDS, including impact assessment of flood closures and lane closures by comparing travel times before and after and traffic analysis during special events ( 8 ). Sadabadi et al use the NPMRDS in Maryland to estimate the value of reliability by calibrating appropriate parameters of the stochastic process describing the evolution of travel time ( 9 ). Hafeez and Kasemsarn use the data to characterize delays at railroad grade crossings and inform possible improvements to the facility ( 10 ).…”

Section: Literature Reviewmentioning

confidence: 99%

Using National Performance Management Research Data Set for Corridor Performance Measures: A US-281N Corridor Case Study

Pandey

Juri

2018

Transportation Research Record: Journal of the Transportation R

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The National Performance Management Research Data Set (NPMRDS), made available by Federal Highway Administration in 2013, provides fine-resolution travel-time data, which have been used in numerous network performance management and operations applications. This article discusses corridor-level performance measures computed using the NPMRDS. Three measures are analyzed on a 20.2-mile long corridor in San Antonio, Texas, including corridor travel time, corridor travel-time reliability, and day-to-day variation in travel time. The primary contributions of this article are the analysis of the impact of using two different approaches for travel-time aggregation across segments—instantaneous and time-dependent approaches—and defining a mean absolute error-based method to identify days when travel times significantly deviate from typical traffic conditions. The findings suggest that the temporal patterns of corridor travel times obtained using instantaneous and time-dependent aggregation approaches are similar; however, instantaneous travel-time estimates lead to inaccuracies that become more apparent during peak hours and for longer segments. In addition, it is found that a [Formula: see text]-means clustering analysis performed on daily travel-time profiles provides a useful statistic for corridor performance analysis. Using this methodology, 9.23% of weekdays in the 20-month study period are classified as atypical for the corridor. The numerical results reinforce the value of the NPMRDS in estimating corridor performance measures and highlight potential limitations of traditional techniques for evaluating corridor performance measures when applied in practice to support enhanced traffic planning and operations.

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“…Table 1 provides an overview of DTA implementations in the literature, developed as part of evaluating project objectives. These DTA models were developed for study areas ranging from a small corridor (2,6) to much larger regional transportation networks (9,10). The current application is among the most large-scale DTA implementations yet.…”

Section: Introductionmentioning

confidence: 99%

Deployment and Calibration Considerations for Large-Scale Regional Dynamic Traffic Assignment: Case Study for Sydney, Australia

Duell

Saxena

Chand

et al. 2016

Transportation Research Record: Journal of the Transportation R

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Dynamic traffic assignment (DTA) has received increasing attention in recent years, and there are numerous examples of practical implementations. This work adds to the literature by describing the ongoing experience of building the first large-scale simulation-based DTA model in Australia. The input data for the model are summarized, and an in-depth discussion and an analysis of model output and the calibration process are presented. Current results put 80% of the 322 calibration points spread across the network within an acceptable bound of error, but the project found that alternative metrics of network performance also must be considered so that other aspects of model realism are not neglected. The described DTA model could be used for evaluating important policy decisions and infrastructural development in the context of the macro- and mesoscale network operation. Additionally, this project is a proof of concept for the Australian region and may provide insight to practitioners interested in emerging areas of transport planning and traffic modeling.

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Value of Travel Time Reliability in Transportation Decision Making: Proof of Conceptâ€"Maryland

Cited by 5 publications

References 35 publications

Mixture Models for Fitting Freeway Travel Time Distributions and Measuring Travel Time Reliability

Mixture Models for Fitting Freeway Travel Time Distributions and Measuring Travel Time Reliability

Using National Performance Management Research Data Set for Corridor Performance Measures: A US-281N Corridor Case Study

Deployment and Calibration Considerations for Large-Scale Regional Dynamic Traffic Assignment: Case Study for Sydney, Australia

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