English, 10 pages, 14 figures
Keywords: brake test, roll brake test bench, accelerometer, commercial vehicles

Evaluation of commercial vehicle brake performance is essential for vehicle traffic safety. Depending on the situation, vehicle brake performance control can be regular/periodical (MOT test, DEKRA vehicle inspection) or occasional (after brake system repair, accident reconstruction etc.). Regular brake performance evaluation is generally done under artificial circumstances, using a roll brake test bench. Occasional brake performance tests are also often done on roll brake test benches but sometimes - especially on field, when making real world brake tests - a 5th wheel or a decelerometer is used for this purpose. Real world brake tests enable the investigation of the dynamic behavior of the vehicle during braking. Unlike under static circumstances (test benches), there is deceleration dependent load change on the axles during the braking process that has great influence on the achievable deceleration. The paper presents a comparison of real world tests and roll brake test bench brake performance tests performed on different types of commercial vehicles.