The objective of the present study is to provide an overview of the effects of selected Advanced Driver Assistance systems (ADAS), namely intelligent speed adaptation, collision warning and alcolock on driving behaviour and road safety. The methodology, developed within the SafetyCube project, was implemented in that purpose. International published studies and reports were selected and then analyzed. For each specific ADAS, the applied methodology included a rigorous and detailed literature search, qualitative analysis of studies in terms of design, methods and limitations and synthesis of findings and meta-analyses, when feasible. The findings of the present study are based on 18 high quality published studies, reports and relevant meta-analyses. Results indicate that in-vehicle technologies and related systems have the potential of playing a very important role on improving road safety. A second remark is that indirect road safety indicators are usually examined, whilst crashes and injuries are rarely considered, due to lack of relevant data. For instance, the effect of alcolock is mainly measurable through the percentage of engine size stops, the reduction in alcohol-related fines and DUI recidivism. Similarly, the effectiveness of collision warning systems is usually examined on the basis of surveys of driving performance, whilst at the same time the costs must be overcome as existing cost-benefit analyses indicate. Overall, there is lack of both quantitative reviews in the form of meta-analyses and qualitative reviews, because relevant research is relatively limited.