Routing strategies based on the macroscopic fundamental diagram

Routing strategies based on the macroscopic fundamental diagram

Knoop, V.L.
Hoogendoorn, S.P.
Van Lint, J.W.C.

Civil Engineering and Geosciences

Transport and Planning

2012-01-22

An excess number of vehicles in a traffic network will reduce traffic performance. This reduction can be avoided by traffic management. In particular, traffic can be routed such that the bottlenecks are not oversaturated. The macroscopic fundamental diagram provides the relation between the number of vehicles and the network performance. One can apply traffic control on this level, in order to overcome computational complexity of network-wide control using traditional control levels of links or vehicles. Main questions in the paper are: (1) how effective is traffic control using aggregate variables compared to using full information and (2) does the shape of the macroscopic fundamental diagram change under traffic control. A grid network with periodic boundary conditions is used as example, and is split up into several subnetworks. The following routing strategies are compared: (1) the shortest path in distance, (2) the path shortest in time (dynamic due to congestion), (3) an approximation of the path shortest in time, but calculated using only variables aggregated for over a subnetwork, (4) an approximation of the path shortest in time, but calculated using only subnetwork accumulation. For routing strategy 3 and 4 only information aggregated over the subnetwork is used. The results show improved traffic flow using detailed information. Effective control is also possible using aggregated information, but only with the right choice of a subnetwork macroscopic fundamental diagram. Furthermore, when optimizing with detailed information – an hence in a subnetwork – the macroscopic fundamental diagram changes.

http://resolver.tudelft.nl/uuid:133eab8d-58e9-41d5-8efb-5a54ab0f90df

Transportation Research Board

91st Annual Meeting Transportation Research Board, Washington, USA, 22-26 January 2012; Authors version

Institutional Repository

conference paper

(c) 2012 The Author(s)