Key to understanding the needs and tools of road infrastructure management is identifying the hazards and their sources involved in having no or faulty road restraint systems. Clarity is also needed on why the systems are wrongly designed, constructed, built and operated. To ensure that the problem is adequately understood, research and site observations were conducted and mathematical models were built to describe the level of roadside risk. To aid studies of road safety barrier and other road safety equipment functionality, it is vital to carry out field crash tests and crash test simulations. The main goal of the work is to develop a method for selecting optimal road restraint systems.