Observations on regression analysis of travel distance on airline distance
In the modeling of urban areas airline distance is often used as a proxy for travel time or distance. This practice has been justified by a high coefficient of determination (R2) between these variables in a random sample of pairs of traffic zones. The ratio of travel distance to airline distance has been used as a measure of network efficiency and called the route factor. This exercise uses hypothetical examples to examine network structure, congestion, and trip production as determinants of route factors and of R2 values of travel distance regressed on airline distance.
The Lowry Model Heritage
Abstract The Lowry model constituted a breakthrough of a particularly intractable conceptual barrier. Notwithstanding its attractive features, including the promise of meaningful operationality, the model has been implemented in only a few domestic applications; its adapters abroad have had more success. In this process, the model has gradually been transformed to more satisfactorily meet the requirements of the regional and transportation planning agencies that depend on allocation modeling. As newly developing conceptual embellishments are made operational, the Lowry model should become an instrument that will enlarge our knowledge of the metropolis and lay a solid foundation for the next generation of models.
Computer Simulation Modeling
Computer simulation as a research methodology is presented as the intersection of modeling, simulation, and computer analysis. Five component parts of simulation models are identified: input variables, output variables, assumptions, algorithms, and parameters. Computer simulation (CSM) has two primary uses for those interested in the study of organizations or who work within them: theory development and policy planning. The advantages and disadvantages of CSM for each of these purposes are examined and recent examples for each are explored.