Effect of pavement friction treatments for vehicle lateral stability on curves: a simulation study

Understanding how wet-pavement treatments affect vehicle dynamic performance remains limited. This study employs CarSim® to simulate the effect of three friction restoration treatments - regular hot mix asphalt (RHMA), longitudinal grooving (LG), and high friction surface treatment (HFST) - on vehicle lateral stability in wet road conditions. Simulations use a validated passenger car model on a curved roadway with polished asphalt (PHMA), analysing a 90-degree turn (46 m radius) across varying speeds, treatment lengths, and superelevation rates (2%-8%). Results show that in wet conditions, the vehicle experiences severe understeer and significant deviation from the intended path due to low road friction and tire grip forces. Treatments with higher friction coefficients, such as LG and HFST, provide greater tire lateral forces, enabling the vehicle to safely negotiate curves at higher speeds. The study highlights the importance of concentrating friction restoration treatment in curves, with at least 80% coverage to maximize its effectiveness.