Print Email Facebook Twitter Empirics of a generalized macroscopic fundamental diagram for urban freeways Title Empirics of a generalized macroscopic fundamental diagram for urban freeways Author Knoop, V.L. Hoogendoorn, S.P. Faculty Civil Engineering and Geosciences Department Transport & Planning Date 2013-01-13 Abstract Due to increasing exchange of data between measurement sites, the area over which traffic control is applied increases. This leads to three new challenges: (1) working with the large quantities of data (transmit, store), (2) estimating the traffic state, (3) controlling a large area with many controllers (and hence large solution space). This paper introduces a new way of describing the traffic state for a large area, which requires much less data and nevertheless gives an accurate representation of the state. The Macroscopic Fundamental Diagram (MFD) which links the production, i.e. the average flow, to the accumulation, i.e. the average number of vehicles in an area. This paper shows that this can be generalized to a generalized macroscopic fundamental diagram (GMFD) for urban freeways, which relates the production to the accumulation and the spatial spread of density. Analysis of 10 months of data of the Amsterdam ring road freeway shows that this is a continuous function, which increases and decreases with accumulation like a fundamental diagram, and decreases with the spatial spread of density. The predictive performance is tested by using a non-parametrized fit and by fitting a functional form, which perform equally well. Predicting the production is important especially near the maximum production. The GMFD explains much more of the spread in the production than the MFD, especially near this maximum production. Thus, this lean traffic state description can be used in a setting a target for traffic control. To reference this document use: http://resolver.tudelft.nl/uuid:240b29b7-b860-4e8e-9bb4-9b9501213d08 Publisher Transportation Research Board Source 92nd Annual Meeting Transportation Research Board, Washington, USA, 13-17 January 2013; Authors version Part of collection Institutional Repository Document type conference paper Rights (c) 2013 The Author(s) Files PDF 291263.pdf 6.79 MB Close viewer /islandora/object/uuid:240b29b7-b860-4e8e-9bb4-9b9501213d08/datastream/OBJ/view