01100419

Component

https://doi.org/10.3141/2085-07

http://scholar.google.com...elli&publication_year=2008

The estimation and correction of the origin–destination (O-D) matrix from traffic counts is a classical procedure usually adopted in transport engineering by practitioners to improve the overall reliability of transport models. Recently, Papola and Marzano showed through laboratory experiments that this procedure is generally not able to provide an effective correction of the O-D matrix. This result can be justified from a theoretical standpoint because of the lower number of stochastic equations (independent observed link flows) with respect to the unknowns (O-D flows). The current study confirms, first, that this circumstance represents the main reason for failure of the procedure by showing that good correction is generally obtained when the number of equations is greater than the number of unknowns. Then, since this circumstance does not occur in practice, in which the number of O-D pairs is usually much greater than the number of link counts, the study explores alternative assumptions and contexts that allow for a proper balance between unknowns and equations. In more detail, this balance can be achieved by moving to within-day dynamic contexts, in which a much larger number of equations is generally available. Obviously, to bound the corresponding increase in the number of unknowns, specific reasonable hypotheses in O-D flow variation across time slices must be introduced. In that respect, the effectiveness of the O-D matrix correction procedure in the usually adopted linear hypothesis on the dynamic process evolution of O-D flows and under the assumption of constant distribution shares is analyzed.

01120896

English

pp 57-66

2008

Transportation Research Record: Journal of the Transportation Research Board

9780309125963

Print

References (34) ; Tables (6)

Estimating; Origin and destination; Traffic counts; Traffic flow; Trip matrices

Correction (Mathematics)

Highways; Planning and Forecasting; I72: Traffic and Transport Planning

TRIS, TRB

Jan 29 2008 2:50PM

• Adaptive Route Choice Models in Stochastic Time-Dependent Networks
• Dynamic Network Loading Model with Explicit Traffic Wave Tracking
• Dynamic Origin–Destination Demand Estimation Using Turning Movement Counts
• Enhanced Lagged Cell-Transmission Model for Dynamic Traffic Assignment
• Generalized Wardrop Principle and Its Application in Regional Transportation
• Incorporating Within-Day Transitions in Simultaneous Offline Estimation of Dynamic Origin–Destination Flows Without Assignment Matrices
• Lower-Bound Solution Algorithm for Equilibrium Signal-Setting Problem
• Measurement of Uncertainty Costs with Dynamic Traffic Simulations
• Modeling User Responses to Pricing: Simultaneous Route and Departure Time Network Equilibrium with Heterogeneous Users
• Probit-Based Time-Dependent Stochastic User Equilibrium Traffic Assignment Model
• Robust Pricing of Transportation Networks Under Uncertain Demand
• Simultaneous Perturbation Stochastic Approximation Algorithm for Solving Stochastic Problems of Transportation Network Analysis: Performance Evaluation
• Stochastic Multiclass Traffic Assignment with Consideration of Risk-Taking Behaviors
• Stochastic User Equilibrium Model with Implicit Travel Time Budget Constraint