Fare dodgers were quantified for the purposes of the study by a series of four random checks conducted on all passengers in a train, bus or metro train between March 1985 and November 1986. Comparisons were drawn between the number of illegal passengers counted during the first check with figures from subsequent checks. To assess the impact of vandalism, repair costs to vehicles, rolling stock, and metro stations were compared with assessments by damage experts, passengers, and staff. Representative samples of passengers were surveyed in November 1985 and September 1986. Questions covered the responsibilities of the task force, their performance, the safety of the system, and cooperation of the staff in providing information. Regular staff as well as the new task force, were administered questionnaires about their jobs and attitudes towards the new supervisory force. Analysis of the results showed a decline in fare dodging, confirming the theory that petty crime can be controlled by increased surveillance. No firm conclusions could be drawn from the figures about the impact on vandalism. However, increased staff presence did not reduce passengers' concerns about safety on the Dutch public transport system. 1 Figure and 10 references. (Author abstract modified)