Abstract
This article is one in a series on a language for the control of traffic processes and a computer program package for traffic control (FLEXSYT). It describes a vehicle-actuated traffic control program on a roundabout in utrecht. Various possibilities for the control of bicycles were studied. Public transport has priority. On one leg of the roundabout the number of lanes was increased. Better control of bicycle traffic slightly increases time losses for other road users. More lanes per leg are very favourable. (author/publisher)