ALTHOUGH THE STUDIES DO NOT GIVE A FIRM ANSWER, THEY OFFER SOME TENTATIVE CONCLUSIONS: TRANSIT CRIME AND VANDALISM CAN EXERT STRONG INFLUENCE ON DECISIONS CONCERNING USE OF URBAN TRANSIT, BUT THERE ARE MANY VARIATIONS DEPENDING ON THE VOLUME OF CRIME OR VANDALISM IN THE AREA SERVED BY A PARTICULAR ROUTE, THE TRANSPORTATION ALTERNATIVES AVAILABLE TO PASSENGERS, THE HOURS AT WHICH THEY MUST RIDE, AND OTHER FACTORS. IN GENERAL, TRANSIT CRIME AND VANDALISM ARE MORE LIKELY TO INFLUENCE PASSENGER DECISIONS CONCERNING RIDING ON RAPID TRANSIT THAN ON BUSES. RIDERS ARE MORE LIKELY TO VIEW WITH SERIOUS CONCERN THE POTENTIALLY MENACING ASPECTS OF ROWDYISM SUCH AS VERBAL THREATS AND VANDALISM THAN 'NUISANCE' ASPECTS SUCH AS THE PUSHING AND SHOVING INVOLVED IN HORSEPLAY. RIDERS' CONCERN IS LIKELY TO BE MORE INTENSE WHEN THEY PERSONALLY WITNESS CRIME OR SERIOUS ROWDYISM THAN WHEN THEY ARE NOT PERSONALLY INVOLVED. THOSE WHO ARE RELUCTANT TO RIDE URBAN TRANSIT BECAUSE OF PERSONAL SECURITY CONSIDERATIONS LEAST FAVOR RIDING AFTER 7:00 P.M. TRANSIT CRIME AND VANDALISM MAY HAVE A POTENTIAL INFLUENCE ON ALL CLASSES OF RIDERS REGARDLESS OF AGE OR SEX, ALTHOUGH POSSIBLY NOT IN THE SAME DEGREE. IT IS EXTREMELY DIFFICULT TO ESTABLISH THAT A GIVEN CHANGE IN RIDERSHIP IS CAUSED BY A SINGLE FACTOR SUCH AS CRIME OR VANDALISM. IN ANY SITUATION, THERE MAY BE A COMBINATION OF FACTORS THAT INFLUENCE RIDERSHIP AND MAKE IT ALL BUT IMPOSSIBLE TO DETERMINE THE DEGREE OF INFLUENCE OF ANY ONE FACTOR. (AUTHOR ABSTRACT) MILWAUKEE, BALTIMORE, CLEVELAND, CHICAGO