Address-based computation of intra-cell distances for travel demand models

Abstract

Intra-cell travel is a difficult topic in zone-based travel demand models. In the past, different strategies were applied to approximate the average intra-cell distances by using zone size, diameter, distances to neighbors and other techniques. In this work we examine a new approach which uses address coordinates and a high performance routing program to achieve more accurate results. We apply our method to three different zoning schemes for the city of Berlin, Germany. The result consists of average travel distances for each zone based on all potential destinations. Surprisingly, the ratio of network distance and beeline distance is independent from the three different zoning schemes tested. This detour-factors depend only on the street network. For beeline distances larger than 400m, we identify a simple transfer function between beeline and travel distance, which extends the classic transfer functions between different zones to intra-zone distances. We show that many distances below 100m belong to a second class of intra-cell routes, which corresponds to the routing in a Manhattan-block grid. These two classes describe the intra-cell distances in our example quite well and we expect this approach to be helpful to examine other areas.