This paper presents improved time-dependent control strategies for small freeway networks with bottlenecks and unique origin-destination (O-D) paths. It is assumed that there are no spillovers from any of the freeway exits so that freeway queues and delays can be completely avoided by regulating access to the system so as to maintain bottleneck flows strictly below capacity. It is also assumed that the time-dependent O-D table and the time-dependent bottleneck capacities are known, although not always a priori. The proposed control strategies attempt to minimize the total delay while avoiding queues inside the system. The problem is formulated as a constrained calculus of variations exercise that can be cast in the conventional form of optimal control theory and can also be discretized as a mathematical program. Although the first-in first-out (FIFO) requirement for the access queues introduces undesirable non-linearities, exact solutions for 4 important special cases can be obtained easily. A greedy heuristic algorithm is proposed for the general case. The algorithm is non-anticipative in that it regulates access at the current time without using future information. As a result, it is computationally efficient and can be bolstered with dynamically-updated information.

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    The Boulevard, Langford Lane
    Kidlington, Oxford  United Kingdom  OX5 1GB
  • Authors:
    • Lovell, D J
    • Daganzo, C F
  • Publication Date: 2000-4


  • English

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  • Accession Number: 00789511
  • Record Type: Publication
  • Files: TRIS, ATRI
  • Created Date: Mar 25 2000 12:00AM