Safety aspects in a large-scale experiment with Intelligent Speed Adaptation; The design of an evaluation framework using open interviews All sorts of in-vehicle Intelligent Transport Systems are being designed and, in the meantime, a number of 'simple' systems have already been introduced. Until now however, safety evaluations are often limited and one-sided. The safety effects that are expected, for example those based on studies with traffic simulators or an instrumented vehicle, will have to be confirmed in well-designed large-scale practical tests. This study, therefore, deals with the design of such an evaluation study. This project attempts to draw up a so-called evaluation framework with safety aspects that should be included in a large practical study. To do this, 10 experts were presented with a case: a large-scale practical test with Intelligent Speed Adaptation (ISA). All experts were or had been involved in the design and carrying out of large-scale ISA tests in the Netherlands. In open interviews, the experts were asked to indicate all possible safety problems after large-scale implementation of ISA, and to explain them further. The following points were dealt with: the cause of the problems, the extent to which they may be allowed to occur, the possibility and necessity of measuring the problems, and how they can possibly be prevented. Finally, every expert was asked to rank the 'own' list of safety issues mentioned according to importance. All safety aspects mentioned have been grouped in four different safety levels that are distinguished for such measures. The first level is that of the functional safety, which contains problems arising from the design of the ISA system (technical reliability, chance of system failure, etc.). The second level is that of the individual driver. This is aimed at the interaction between the user and the application (suitability, distraction, etc.). The third level is that of interaction between road users, which concentrates on the interaction between driver (incl. the application) and the direct surroundings (e.g. distances). The fourth level is that of road safety in which there are problems covering the whole traffic system. As well as having looked at each level, the origin of the safety aspects mentioned was examined. This can lie in the designed, intended traffic process, i.e. the speed of ISA equipped vehicles is monitored and, if necessary, corrected. The origin can also lie in a deviation from this intended process. The majority of the safety aspects mentioned by the interviewed experts seem to be a result of the desired process. In addition, 9 of the 13 issues were related to the functional safety level or the individual driver level. The three aspects found by the experts to be the most important are, first of all, behavioural risks that are related to a decline in alertness. Examples of this are riskier driving behaviour, overestimating the reliability of the ISA, laziness, and distraction by all the electronics in the vehicle. Secondly, the (technical) functioning of the ISA system is considered to be important, such as the inaccuracy of the positioning and the less than optimal functioning of the active acceleration pedal. A third important aspect was irritation with the mix of vehicles with and without ISA, possibly leading to drivers of a vehicle without ISA overtaking dangerously or showing aggressive behaviour. The methods that the experts suggest to measure the safety aspects mentioned appear to be mono- disciplinary: they only mention those methods used frequently in their own field for the various safety levels. However, in a good evaluation, attention should also be paid to aspects that can occur at different levels. To do this, a multidisciplinary approach seems necessary.