ATSI manufactures professional electrical test and measurement instruments for the traffic signal, traffic data collection, and parking industries. Excellent cus…ATSI manufactures professional electrical test and measurement instruments for the traffic signal, traffic data collection, and parking industries. Excellent customer support and expert technical assistance are our top priority. Our products have earned a strong reputation for quality and reliability. From innovative product design to service that stand behind our products, ATSI has become the standard for traffic signal test equipment.