The present paper presents an in-vehicle system for traffic violation alert and management. The system hardware consists of a combination of an on-board computer vision system for traffic sign detection and recognition with a data recorder device for traffic violation alert and management. At present, traffic violations are only focused on three signs: namely speed limit, stop sign, and forbidden turning. The system is designed to warn drivers about potential traffic violations by emitting acoustical messages through vehicle loudspeakers. These messages are issued with sufficient notice to provide the driver with enough time to react to the oncoming traffic situation. However, when a traffic violation is committed, the corresponding offence information such as vehicle speed, GPS location, and other driving parameters, are saved in a database for off-line analysis. In addition, an auxiliary application permits the registered traffic violations to be represented as a standard Google Earth map. The prototype was tested in a real scene under different lighting conditions and showed reasonable results.