TY - JOUR
T1 - Implementing first-in-first-out in the cell transmission model for networks
AU - Carey, Malachy
AU - Bar-Gera, Hillel
AU - Watling, David
AU - Balijepalli, Chandra
N1 - Funding Information:
We would like to thank Wai Yuen Szeto for discussions in past years about methods for approximating or implementing FIFO. We also wish to thank two reviewers for their insightful comments and queries. If any errors remain in the paper we hope that they may provide research opportunities for later researchers! We also wish to thank the UK Engineering and Physical Sciences Research Council (EPSRC) for their support under Grant Number EP/G051879 .
PY - 2014/1/1
Y1 - 2014/1/1
N2 - In traffic assignment models with time-varying flows (dynamic network loading or dynamic traffic assignment), overtaking behaviour is normally not included in the model and, in that case, it is important that the model at least approximates first-in-first-out (FIFO), to prevent deviations from FIFO that are arbitrary or unrealistic or not physically possible. For the cell transmission model (CTM) it has recently been shown that the usual recommended method for preserving FIFO will ensure FIFO for each cell taken separately but does not fully ensure FIFO in the transition between cells and hence does not fully ensure FIFO for sequences of cells or for links or for routes. As a result, deviations from FIFO can easily occur and cumulate along the links or routes. In view of that, we define and analyse three different levels of satisfaction or approximation of FIFO, together with corresponding methods for achieving them. Two of these are existing methods and one is new. We develop, analyse and compare the three methods and the extent to which each of them adheres to FIFO for sequences of cells and links or routes. Also, for two of the methods we present a more detailed algorithm for applying them within the CTM. The paper is concerned with how to implement FIFO in the CTM and not with testing for FIFO or measuring deviations from FIFO.
AB - In traffic assignment models with time-varying flows (dynamic network loading or dynamic traffic assignment), overtaking behaviour is normally not included in the model and, in that case, it is important that the model at least approximates first-in-first-out (FIFO), to prevent deviations from FIFO that are arbitrary or unrealistic or not physically possible. For the cell transmission model (CTM) it has recently been shown that the usual recommended method for preserving FIFO will ensure FIFO for each cell taken separately but does not fully ensure FIFO in the transition between cells and hence does not fully ensure FIFO for sequences of cells or for links or for routes. As a result, deviations from FIFO can easily occur and cumulate along the links or routes. In view of that, we define and analyse three different levels of satisfaction or approximation of FIFO, together with corresponding methods for achieving them. Two of these are existing methods and one is new. We develop, analyse and compare the three methods and the extent to which each of them adheres to FIFO for sequences of cells and links or routes. Also, for two of the methods we present a more detailed algorithm for applying them within the CTM. The paper is concerned with how to implement FIFO in the CTM and not with testing for FIFO or measuring deviations from FIFO.
KW - Cell transmission model
KW - Dynamic network loading
KW - Dynamic traffic assignment
KW - Exit-flow models
KW - FIFO
KW - First-in-first-out
UR - http://www.scopus.com/inward/record.url?scp=84901047103&partnerID=8YFLogxK
U2 - 10.1016/j.trb.2014.04.001
DO - 10.1016/j.trb.2014.04.001
M3 - Article
AN - SCOPUS:84901047103
SN - 0191-2615
VL - 65
SP - 105
EP - 118
JO - Transportation Research Part B: Methodological
JF - Transportation Research Part B: Methodological
ER -