Open AccessDistributions of travel time variability on urban roads
Author(s) -
Susilawati Susilawati,
Taylor Michael A. P.,
Somenahalli Sekhar V. C.
Publication year - 2013
Publication title -
journal of advanced transportation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 46
eISSN - 2042-3195
pISSN - 0197-6729
DOI - 10.1002/atr.192
Subject(s) - reliability (semiconductor) , skew , measure (data warehouse) , travel time , computer science , transport engineering , bimodality , distribution (mathematics) , econometrics , mode (computer interface) , trip distribution , statistics , engineering , data mining , mathematics , telecommunications , mathematical analysis , power (physics) , physics , quantum mechanics , galaxy , operating system
SUMMARY Reliability is an important factor in route, mode and also departure time choice analysis and is a key performance indicator for transport systems. However, the current metrics used to measure travel time variability may be not sufficient to fully represent reliability. Better understanding of the distributions of travel times is needed for the development of improved metrics for reliability. A comprehensive data analysis involving the assessment of longitudinal travel time data for two urban arterial road corridors in Adelaide, Australia, demonstrates that the observed distributions are more complex than previously assumed. The data sets demonstrate strong positive skew, very long upper tails, and sometimes bimodality. This paper proposes the use of alternative statistical distributions for travel time variability, with the Burr Type XII distribution emerging as an appropriate model for both links and routes. This statistical distribution has some attractive properties that make it suitable for explicit definition of many travel time reliability metrics. Copyright © 2011 John Wiley & Sons, Ltd.