Abstract:
A model is described for detemining the seed or propensity matrix from which turning flows at an intersection can be estimated to match given inflow and outflow volumes, using the biproportional method when intersection-specific counts are unavailable. Normalizing counts to standard inflow and outflow totals is demonstrated to reveal a striking similarity in underlying propensities across intersections. Functional class is shown to be a poor explanator of different propensities. Propensity is modeled as a function of angle, competing short cuts, presence of deadend approaches, and grid density. Estimates made using the propensity model seed are found to have prediction errors of about 6% of inflow volume, compared to errors of 4% for estimates that use an intersection-specific count as seed.
Supplemental Notes:
This paper appears in Transportation Research Record No. 1287, Traffic Flow, Capacity, Roadway Lighting, and Urban Traffic Systems 1990. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
