Safety is a factor that needs to be prioritised at the workplace. Every worker in the sector values a safe and secure work environment, so workplace safety is important for all of them. Highway maintenance workers' safety is critical since they are placed in the highway's work zone to perform maintenance tasks. There are many incidents involving maintenance workers when working on the highway since there is a poor danger detection system in place to alert workers during the working process. The goal of this research is to build an improved safety system for maintenance workers on the job. There are two objectives in this study, which are to study the parameters effect of applying a distance sensor in finding the best safety vehicle detection at an emergency lane and the reliability test of a signal warning detector (SWAD) casing for the best installation at a road maintenance vehicle. The SWAD set up and experimental performance field test have been done. The study was conducted by setting up the SWAD at Padang Kawad, UTHM, and testing its ability to detect the presence of a vehicle at different distances and sensor heights. The vibration test for SWAD circuit casing has be done using a vibration shaker. The results showed that the SWAD was able to detect the presence of a vehicle at 90 metres and at a sensor height of 0.7 metres. From the vibration testing for the long pane, we know that the maximum vibration of SWAD’s circuit casing can absorb, which is 13.074 Hz, and the speed of the vibration is 3.8319 m/s. The system can increase the level of safety among highway workers if it is implemented on highways for safety purposes involving highway workers and users of highways.