The validity of the SAGAT-questionnaire: An empirical study using simulated driving situations

In order to develop a valid test tool for further studies about automated driving such as comparing different driver-car interfaces, an experiment investigated situation awareness of the drivers´ surrounding on three different time-periods: 1.25 sec, 1.75 sec. and 2.25 sec. Contrary to expectations, an earlier study showed reductions in situation awareness as the time period increased, which might be explained by an invalid research design. The three time-levels also got subdivided into two different situations. Situation awareness was measured by a SAGAT questionnaire right after the simulation stopped. The present study showed significant higher situation awareness at the highest time-level 2.25 sec., but no significant difference for situation.