A double‐array is a compact and fast data structure for a trie, but it degrades the speed of insertion for a large set of keys. In this paper, two kinds of methods for improving insertion are presented. The basic functions for retrieval, insertion and deletion are implemented in the C language. Comparing with the original double‐array for large sets of keys, the improved double‐array is about six to 320 times faster than that for insertion. Copyright © 2001 John Wiley & Sons, Ltd.

One of the difficulties of route choice modeling is to represent a generation process of choice set explicitly in a network including infinite paths. Since it is expensive and uses many man-hours to collect the data, the analysis of routes that a driver actually used has not been done. Therefore, in the existing route choice model, there is a problem that routes included in a choice set do not necessarily correspond to routes that a driver has actually used. However, with the development of Probe Person Technology that gives location data of the movable body, having a GPS phone, it is possible to collect the data of routes a driver has used without burdening the driver. Then, in this paper, the route data which is available on a private basis and obtained in Probe Person survey is analyzed. The choice set generation methods based on routes drivers actually used are suggested, and the case studies of route choice models are carried out by using it.

No abstract