This report concerns a study on the effects of a prototype intelligent speed adaptor (ISA) in actual traffic within the framework of the project `Automatisering Rijtaak'. Twenty-four subjects were included in a test of effects of feedback on speed behaviour, mental workload and acceptance. Subjects drove an instrumented vehicle in normal traffic on various types of roads with different speed restrictions and in a driving simulator, interacting with other traffic as well as under different speed restrictions. Subjects completed both test parts twice, half of the subjects receiving feedback in the second trial (experimental group), half of the subjects not (control group). The groups differed in several ways, the most important being adaptation of their behaviour under feedback. Subjects in the experimental group behaved more according to traffic rules, in particular speed limits, than subjects in the control group. No differences in workload were found. Several types of feedback were tested to acceptance and rated differentially.
Abstract