Behavioural effects of ISA in different driver categories.

Field studies to investigate the effects of Intelligent Speed Adaptation (haptic respectively auditory warnings) were carried out in Hungary and Spain. In a before/after within subject study, 20 test drivers in each country, tested both the Active Accelerator Pedal and an auditory warning system. Both systems had an effect on speed and the effect was greater for the Active Accelerator Pedal than for the “BEEP”-system. The largest effects of the ISA systems were found on the highest speeds, a very good indicator for this the changes is the 85th percentile speeds. Speed variance decreased too. The decreases were larger for the Active Accelerator Pedal than for the “BEEP”-system. Both the Hungarian and the Spanish participants seem to have a positive attitude towards ISA in general. Both systems were perceived as useful and neither satisfying nor dissatisfying. However the attitudes to the two systems tested were more differentiated and got less positive after one month’s usage. Hungarian drivers seem to be more skeptical to the systems than the Spanish drivers. However, there are no clear differences between the countries when looking at the acceptance, where the only relatively clear difference is that the Hungarian drivers like the AAP less than the BEEP system.