The objective of this work is to present the state-of-the-art on a set of Advanced Driver Assistance Systems (ADAS) with high potential to contribute to the improvement of road safety, traffic efficiency and environmental conditions. This state-of-the-art gives a broad overview of ADA systems under development or in some cases already available. Twenty-seven advanced driver assistance systems are examined, classified into the three distinct phases of the accident process: pre-crash, crash and post-crash as well as into the two categories of driver support functions: tactical and operational. Of each system various aspects are being described, from functional description to market impact, and from user needs to strengths and weaknesses of ADAS, according to the availability of information for these new systems. Intelligent vehicles and roads are the future standard and specialised research should be intensified for the identification of their impact as well as their adaptation to the real user needs for safer and efficient transportation services.