Research on Braking Behavior and Brake Drum Temperature Rise Model of Truck on Continuous Downhill Section of Low-Grade Highway

China has a large mileage base of low-grade highways, and accidents caused by brake failure of heavy-duty trucks occur frequently. To conduct an in-depth study on the braking behavior of truck drivers on continuous downhill sections of low-grade highways, this research, based on the field-measured data of six-axle articulated trains on low-grade highways during long downhill driving, identified the driver’s braking timing on downhill sections with complex horizontal and vertical alignments, analyzed and quantified the characteristics of truck drivers’braking behaviors on continuous downhill sections of low-grade highways, established a joint simulation model of driver behavior in TruckSim simulation software by integrating Matlab/Simulink, and, finally, verified the reliability of the model through comparison. The results show that, on horizontal curve sections, truck drivers are influenced by the curves and will exhibit relatively high-intensity braking behaviors at the end of straight sections and the beginning of the curved sections. On straight downhill sections with a gradient of 2%~9%, the drivers’ braking magnitude is positively correlated with the gradient; According to the radius, the curves are classified into sharp curves, medium curves and gentle curves, and the average brake pedal stroke before entering sharp curves reaches 220 mm, while there is no significant difference in the average brake pedal stroke between medium curves (176 mm) and gentle curves (174 mm). As compared with the brake drum temperature rise prediction models in previous studies that did not consider horizontal alignment factors, the simulation model established in this research is of higher prediction accuracy for brake drum temperature, thus providing a theoretical basis for the traffic safety guarantee on low-grade highways.