The subject of this investigation is the development of an accurate simulation of a truck impacting a commonly found strong post/w-beam guardrail system. Detailed methods for system simulation are proposed herein and several major issues, namely. the use of springs to simulate component crashworthiness behaviour, are investigated. Rail to block-out bolt connection, soil-post-dynamic interaction, and effect of ends of guardrail are modelled and simulated. Soil-post interaction is modelled using both Lagrangian and Eulerian meshes and the results using the two methods are presented herein. Both qualitative and quantitative validation of the crash simulation is presented and discussed. The present paper provides a roadmap for the simulation of highway safety structures.