POSSIBLE SCHEMES FOR INTRODUCING "FEEDBACK" INTO THE FOUR-STEP TRAVEL FORECASTING PROCEDURE VS. THE EQUILIBRIUM SOLUTION OF A COMBINED MODEL: COMPARISONS FOR THE CHICAGO REGION

摘要: The objective of this paper is to examine how solutions produced by various methods introducing "feedback" into the four-step travel forecasting procedure compare with equilibrium solution a model combining trip distribution, mode split and assignment steps. comparisons are performed on sketch-planning Chicago Region about 300 zones 3,000 highway links. From these comparisons, one can learn that iterating process in some ad hoc manner does not produce desired result. Instead, needs apply an algorithm designed converge well-defined flows link times costs determined flows. Progress improving forecasts will result from calls for solving "feedback". Rather, progress be made as professional practitioners begin understand requirements solutions. Then, they must insist their software developers correctly implement algorithms required compute Finally, should FHWA short courses introduce participants contemporary yield properties. Likewise, university instructors textbook authors update new generation professionals principles models.