Modern traffic control devices and traffic management systems designs have become increasingly sophisticated by integrating hardware and software components to solve specific real-time control and monitoring problems. However, many minor system design and operation defects are often unavoidable and difficult to detect. These minor design defects, which sometimes go unnoticed, may often yield misleading information, cause misunderstanding during system implementation, and may even defeat the original system design objectives.This paper describes an innovative, integrated testing procedures for system verification and validation. This process is used in the implementation of a truck warning device for operational safety on directional freeway interchange ramps. The system has been implemented successfully at the interchange located at US 59 and Loop 610 in Houston, Texas.