To address the pressing issue of frequent collisions between over height vehicles and bridges, which pose significant road safety hazards, this study introduces an innovative solution. We have developed an adaptive vehicle height detection algorithm based on single line LiDAR technology. Utilizing two dimensional laser scanning technology, the algorithm automatically identifies the ground and accurately measures vehicle height. Experiments demonstrate that the algorithm effectively limits vehicle height measurement errors to within ±2 cm, achieving a 100% detection rate with 0% false positives during continuous monitoring. Upon detecting over height vehicles, the system immediately signals for video tracking, evidence preservation, or activation of audio visual alarms. These results confirm the algorithm's high precision and reliability in the vehicle height restriction field, along with its stability, adaptability, low cost, and ease of maintenance, thus highlighting its considerable value in this field.