@article{ref1,
title="Additive measures of travel time variability",
journal="Transportation research part B: methodological",
year="2011",
author="Engelson, Leonid and Fosgerau, Mogens",
volume="45",
number="10",
pages="1560-1571",
abstract="This paper derives a measure of travel time variability for travellers equipped with scheduling preferences defined in terms of time-varying utility rates, and who choose departure time optimally. The corresponding value of travel time variability is a constant that depends only on preference parameters. The measure is unique in being additive with respect to independent parts of a trip. It has the variance of travel time as a special case. Extension is provided to the case of travellers who use a scheduled service with fixed headway.<p />",
language="en",
issn="0191-2615",
doi="10.1016/j.trb.2011.07.002",
url="http://dx.doi.org/10.1016/j.trb.2011.07.002"
}