Infrastructure-side traffic monitoring system (20, 30, 50), comprising: - a plurality of sensor units (S1, S2) for capturing sensor data from a traffic cell, - a sensor fusion unit for the fusion of sensor data, - a checking device for checking the correctness of fused sensor data, wherein the checking device is designed to receive fused sensor data from the sensor fusion unit and to carry out a consistency check of the sensor data on the basis of the fused sensor data and to output check results, wherein the checking device comprises at least one of the following checking units: - a redundancy checking unit for checking whether objects are detected by different sensors with a predefined temporal and spatial tolerance, - a sequence checking unit for checking whether a detected movement proceeds in conformity with predetermined criteria, - a shading checking unit for checking whether a detected object is shaded by another object, - a validation device comprising: - a test unit for outputting test patterns for simulating sensor data, wherein a test pattern comprises simulated sensor data, - a validation unit having - a fusion data interface for receiving fused simulated sensor data from the sensor fusion unit, - a check data interface for receiving check results generated by the checking device on the basis of the fused simulated sensor data, - a test pattern interface for receiving the test patterns output from the test unit, wherein the test unit is designed to transmit the simulated sensor data to the sensor fusion unit, which is configured to generate therefrom fused simulated sensor data and to transmit them to the checking device, which is configured to process the fused simulated sensor data and to generate associated check results, wherein the validation device is configured to determine a validity of the check results on the basis of a comparison with the test patterns and to generate validation results. - a plurality of sensor units (S1, S2) for capturing sensor data from a traffic cell, - a sensor fusion unit for the fusion of sensor data, - a checking device for checking the correctness of fused sensor data, wherein the checking device is designed to receive fused sensor data from the sensor fusion unit and to carry out a consistency check of the sensor data on the basis of the fused sensor data and to output check results, wherein the checking device comprises at least one of the following checking units: - a redundancy checking unit for checking whether objects are detected by different sensors with a predefined temporal and spatial tolerance, - a sequence checking unit for checking whether a detected movement proceeds in conformity with predetermined criteria, - a shading checking unit for checking whether a detected object is shaded by another object, - a validation device comprising: - a test unit for outputting test patterns for simulating sensor data, wherein a test pattern comprises simulated sensor data, - a validation unit having - a fusion data interface for receiving fused simulated sensor data from the sensor fusion unit, - a check data interface for receiving check results generated by the checking device on the basis of the fused simulated sensor data, - a test pattern interface for receiving the test patterns output from the test unit, wherein the test unit is designed to transmit the simulated sensor data to the sensor fusion unit, which is configured to generate therefrom fused simulated sensor data and to transmit them to the checking device, which is configured to process the fused simulated sensor data and to generate associated check results, wherein the validation device is configured to determine a validity of the check results on the basis of a comparison with the test patterns and to generate validation results. wherein the test unit is designed to transmit the simulated sensor data to the sensor fusion unit, which is configured to generate therefrom fused simulated sensor data and to transmit them to the checking device, which is configured to process the fused simulated sensor data and to generate associated check results, wherein the validation device is configured to determine a validity of the check results on the basis of a comparison with the test patterns and to generate validation results.