The purpose of the School Trip Safety and Urban Play Areas research project was to develop guidelines for the protection of young pedestrians (5 to 14 yrs.) walking to and from school. The play street is a street temporarily closed to traffic while a variety of supervised recreational activities for all age groups take place. The report describes what a play street is, why they should be considered by urban policy makers, how a program is set up, how the streets are selected from candidate neighborhoods, criteria for traffic engineering surveys, street closure, vehicular control, parking strategies, and street and user demongraphics in New York City. The information is based on surveys and observations of the New York City and Pheladelphia play streets.