Trip Travel-Time Reliability: Issues and Proposed Solutions

The estimation of path or trip travel-time reliability is critical to any advanced traveler information system. The state-of-practice procedures for estimating path travel-time reliability assume that travel times follow a normal distribution and that segment travel times are independent (i.e., trip variance is a summation of segment variances). The present study analyzes Automatic Vehicle Identification (AVI) data from San Antonio, Texas, and simulated data to demonstrate through goodness-of-fit tests that a log-normal travel-time distribution is valid only under steady-state conditions, whereas a normal distribution is not valid. In the present article, the authors propose five methods for the estimation of path travel-time variance from its component segment travel-time variances. The analysis demonstrates that computing the trip travel-time coefficient of variation as the conditional expectation over all realizations of roadway segments provides estimates within 70% of trip travel-time variance for both uncongested and congested conditions.

[1]  Haitham Al-Deek,et al.  Using Real-Life Dual-Loop Detector Data to Develop New Methodology for Estimating Freeway Travel Time Reliability , 2006 .

[2]  Francois Dion,et al.  Estimating dynamic roadway travel times using automatic vehicle identification data for low sampling rates , 2006 .

[3]  Michael G.H. Bell,et al.  Transportation Network Analysis: Bell/Transportation Network Analysis , 1997 .

[4]  Yasuo Asakura,et al.  Reliability Measures of Regional Road Network Dueing to Daily Variance of Traffic Flow , 1989 .

[5]  Hesham Rakha,et al.  VEHICLE PROBES AS REAL-TIME ATMS SOURCES OF DYNAMIC O-D AND TRAVEL TIME DATA , 1993 .

[6]  Kyriacos C. Mouskos,et al.  Evaluation of the TRANSCOM's system for managing incidents and traffic (TRANSMIT) , 2000, IEEE Trans. Intell. Transp. Syst..

[7]  Haitham Al-Deek,et al.  New Methodology for Estimating Reliability in Transportation Networks with Degraded Link Capacities , 2006, J. Intell. Transp. Syst..

[8]  Thomas F. Golob,et al.  Structural Equation Modeling For Travel Behavior Research , 2001 .

[9]  Hesham Rakha,et al.  INTEGRATION MODELING FRAMEWORK FOR ESTIMATING MOBILE SOURCE EMISSIONS , 2004 .

[10]  Jitamitra Desai,et al.  A discrete optimization approach for locating Automatic Vehicle Identification readers for the provision of roadway travel times , 2006 .

[11]  Heidrun Belzner,et al.  A New Measure of Travel Time Reliability for In-Vehicle Navigation Systems , 2008, J. Intell. Transp. Syst..

[12]  Michael G.H. Bell,et al.  A game theory approach to measuring the performance reliability of transport networks , 2000 .

[13]  Dongjoo Park,et al.  Dynamic and stochastic shortest path in transportation networks with two components of travel time uncertainty , 2003 .

[14]  Y Iida,et al.  Transportation Network Analysis , 1997 .

[15]  William L Eisele ESTIMATING TRAVEL TIME MEAN AND VARIANCE USING INTELLIGENT TRANSPORTATION SYSTEMS DATA FOR REAL-TIME AND OFF-LINE TRANSPORTATION APPLICATIONS , 2001 .

[16]  Francois Dion,et al.  Vehicle Dynamics Model for Estimating Maximum Light-Duty Vehicle Acceleration Levels , 2004 .

[17]  Hesham A. Rakha,et al.  Estimating Path Travel-Time Reliability , 2006, 2006 IEEE Intelligent Transportation Systems Conference.

[18]  H. J. Van Zuylen,et al.  Monitoring and Predicting Freeway Travel Time Reliability: Using Width and Skew of Day-to-Day Travel Time Distribution , 2005 .

[19]  Yasuo Asakura,et al.  Empirical Analysis of Travel Time Reliability Measures in Hanshin Expressway Network , 2009, J. Intell. Transp. Syst..

[20]  Hesham Rakha,et al.  Impact of Differences in Driver-Desired Speed on Steady-State Traffic Stream Behavior , 2006 .

[21]  Hesham Rakha,et al.  VARIABLE POWER VEHICLE DYNAMICS MODEL FOR ESTIMATING TRUCK ACCELERATIONS , 2002 .

[22]  Hesham Rakha,et al.  Comparison and calibration of FRESIM and INTEGRATION steady-state car-following behavior , 2003 .

[23]  Hesham Rakha,et al.  INTEGRATION 2.30 Framework for Modeling Lane-Changing Behavior in Weaving Sections , 2004 .

[24]  D J Jeffery THE POTENTIAL BENEFITS OF ROUTE GUIDANCE , 1981 .

[25]  Robert E. Skinner Cost-Effective Performance Measures for Travel Time Delay , Variation , and Reliability , 2003 .