@article{ref1,
title="Phase based jam warnings: an analysis of synchronized flow with floating car data",
journal="Journal of intelligent transportation systems: technology, planning, and operations",
year="2020",
author="Kerner, B. S. and Rehborn, H. and Molzahn, Sven-Eric",
volume="24",
number="6",
pages="569-584",
abstract="Based on an empirical study of floating car data (probe vehicle data), we have found the following microscopic features of empirical synchronized flow that are relevant for jam warning methods: (i) In accordance with Kerner's three-phase traffic theory, the empirical speed decrease (speed drop) denoted by Δv that occurs due to vehicle deceleration at the upstream front of synchronized flow is a complex time function. (ii) The empirical function Δv can be considered a &quot;jam wall&quot; at which different vehicles exhibit sometimes very different speed drops Δv occurring at different road locations. Because each of the vehicles decelerates within the &quot;jam wall&quot; at different road locations, the &quot;jam wall&quot; moves in space and in time. (iii) The spatiotemporal structure of the empirical &quot;jam wall&quot; is determined by alternations of the synchronized flow and wide moving jam traffic phases at the upstream front of a congested traffic pattern. (iv) During some time intervals, the &quot;jam wall&quot; can disappear and then it can appear once more, and so on; during &quot;jam wall&quot; disappearance, one or a few vehicles can pass a bottleneck while moving in free flow. These empirical findings can be important for the development of reliable jam warning methods as well as other ITS-applications.<p /> <p>Language: en</p>",
language="en",
issn="1547-2450",
doi="10.1080/15472450.2019.1638781",
url="http://dx.doi.org/10.1080/15472450.2019.1638781"
}