In the EU-project INTERSAFE, driver assistance systems were developed to improve safety at intersections. These systems were implemented in two demonstrator vehicles: a VW Phaeton and a BMW 5 series. According to its applicable scenarios, the systems include two assistance functions: traffic light assistant (TLA) and intersection assistant (IA). In order to inspect the systems' functionality and the user acceptance, the onboard environmental sensors and the full systems have been tested. The testing approach and the results are described in this paper. The tests were carried out in three phases: sensor test, system test and user test. Sensor test and system test have proved the functionality of the INTERSAFE system. The systems are able to fulfill the tasks of assisting the driver to avoid potential traffic accidents at an intersection. The user test focused mainly on the user acceptance of the systems and the HMI design. After driving both demonstrator vehicles and experiencing the INTERSAFE systems, the test persons rated the systems helpful and relieving. They stated that these systems could have helped them in their daily driving and would improve the traffic safety.