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An analytical approximation for the macroscopic fundamental diagram of urban traffic
- Source :
-
Transportation Research Part B: Methodological . Nov2008, Vol. 42 Issue 9, p771-781. 11p. - Publication Year :
- 2008
-
Abstract
- Abstract: This paper shows that a macroscopic fundamental diagram (MFD) relating average flow and average density must exist on any street with blocks of diverse widths and lengths, but no turns, even if all or some of the intersections are controlled by arbitrarily timed traffic signals. The timing patterns are assumed to be fixed in time. Exact analytical expressions in terms of a shortest path recipe are given, both, for the street’s capacity and its MFD. Approximate formulas that require little data are also given. For networks, the paper derives an upper bound for average flow conditional on average density, and then suggests conditions under which the bound should be tight; i.e., under which the bound is an approximate MFD. The MFD’s produced with this method for the central business districts of San Francisco (California) and Yokohama (Japan) are compared with those obtained experimentally in earlier publications. [Copyright &y& Elsevier]
- Subjects :
- *TRAFFIC congestion
*TRANSPORTATION research
*TRAFFIC engineering
*TRAFFIC density
Subjects
Details
- Language :
- English
- ISSN :
- 01912615
- Volume :
- 42
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- Transportation Research Part B: Methodological
- Publication Type :
- Academic Journal
- Accession number :
- 33885777
- Full Text :
- https://doi.org/10.1016/j.trb.2008.06.008