Nighttime accident data was studied to determine priorities for accident reduction through the use of improved vehicle roadway illumination. The relationship between the driver, vehicle, environment and target was then modeled, resultingi n thousands of conflicting, yet high priority target points. Prioritized accident data and target similarity was then used to reduce the number of targets to a more manageable number for specificationp urposesT. he resulting specification, based on safe driving needs during nighttime driving conditions, will be the basis for developing future lighting throughout the world.