This paper aims at developing a risk index based on real-data measurements, which can be used either off-line as an evaluation index during the evaluation process which leads to the dramatical reduction of the field test periods, or in real-time like: a safety monitoring tool (e.g. safety user warning system), or a multi-criterion function to be optimized in real time (safety index combined with a traffic index) within several control strategies, such as coordinated ramp metering, speed limit control, route guidance, etc.