This paper presents a multi-objective optimisation strategy for heavy truck suspension systems based on Modified Skyhook Damping (MSD) control, which improves ride comfort and road-friendliness simultaneously. A four-axle heavy truck-road coupling system model was established; the model was then validated with a ride comfort test. Through co-simulations with Adams and Matlab, the effects of passive, semi-active MSD control and active MSD control were analysed and compared. Simulation results indicated that MSD control improves a truck's ride comfort and road-friendliness, while the semi-active MSD control damper obtains road-friendliness comparable with that of the active MSD control damper. Copyright © 2011 Inderscience Enterprises Ltd.