Abstract
20% of the enterprises in the inner town centre of Groningen has a decrease in profit from 5 till 40% by the installation of the traffic circulation plan. The decrease in profit is mostly for big volume-line of business like do-it-yourself shops and furniture-shops. The circulation plan gives fewer visitors during weekdays. A plea is given for the adaptation of the plan by building more parking garage, free parking, free public transport and construction of ring roads.