National Institute of Metrology (Thailand) has developed a Speed Calibration System with a laboratory building to support the enforcement of traffic and transportation operation in the country and to create fairness in law enforcement. The use of law on driving faster than the rate required in order to reduce road accidents that correspond to the problem condition. The agencies that responsible for the said law such as Traffic Police Division, Highway Police Division, Department of Land and Transport including Expressway Authority of Thailand are using various type of vehicle speed detectors both laser speed cameras and speed detection cameras. Therefore, those speed detectors need to be calibrated back to the national measurement standards to be able to use correctly. But at present, it was found that there is no agency in the country is able to provide that service. Therefore, National Institute of Metrology as an organization responsible for procuring, developing and maintaining national measurement standards need to establish a calibration system including technology transfer systems for conveying the accuracy of the measurement results of Speed Calibration in Thailand. The Speed Calibration System, design of a constant velocity generator, belt system and laser receiver was support by Dr. Dai-Hyuk Yu, Head of Center for Time and Frequency and Mr. Jong Koo Lee, Principal Engineer, expert from Korea Research Institute of Standards and Science. The function was held at Speed Calibration Laboratory, NIMT, Pathum Thani Province.