Abstract
A very important factor in optimizing a public transport system is the strong relationship between transport demand and transport facilities (accessibility, speed, frequency). Only partial solutions are available; the most relevant of these are described. On the long term the research by this author is aimed at solving this problem as far as possible. First, research is proposed on the interrelationship of supply and demand by elaborating a particular method yielding partial solutions. For this purpose a computer program is being developed.