A field demonstration study in support of the evaluation of alternative railway-highway grade crossing accident countermeasures was conducted. Guidelines were provided for the development of countermeasure concepts, the selection of candidate countermeasures, countermeasures evaluation methods, and experimental design and procedures. Investigations of the causative factors of accidents showed that maintenance of protective warning devices, driver attention and driver expectancy were precipitating and predisposing factors in accidents. An appraisal of inherent driver safety potential was made which included driver education and licensing, safety programs and law enforcement, attitude and habit components of railway-highway safety and psychophysiological capabilities and limitations. A broad base of data was obtained in a demonstration field study conducted in five states. Information was obtained on driver behavior, knowledge and attitude. Three data collection procedures were used: the Traffic Evaluator System, time-lapse photography, and motorist response to questionnaires. An extensive analysis was performed on the data obtained to suggest countermeasures concepts and to determine target populations for effective countermeasure intervention. Measures of driver performance were developed which were shown to be sensitive to countermeasure intervention. Under restricted conditions, driver looking behavior, crossing speed and speed decrease were shown to be sufficient and valid measures of performance to evaluate the effectiveness of a countermeasures intervention.