The purpose of this report was to develop guidelines for the operational traffic engineer and the transportation researcher to determine when, where and how to use time-lapse photography. this technique permits the large scale sampling of specific events where: the level of detail required, the cost involved, the elimination of data bias due to the presence or interpretations of field data collectors, negates the use of observers or mechanical/electrical devices. Recommendations are made for data collection, data reduction and record keeping associated with both efforts.