Testing the impact of providing concurrent verbal protocols on driving performance
Driving studies, conducted both on-road and in driving simulators, are increasingly utilising the concurrent verbal protocol methodology, whereby participants are instructed to “think aloud” during task performance.
There has long been concern that providing concurrent verbal protocols may interfere with primary task performance. Although previous research has tested the impact of providing concurrent verbal protocols on performance in a range of contexts, none have directly examined the impact on driving performance. It has been suggested, for example, that providing verbal protocols could potentially degrade aspects of driver behaviour, driver cognition, or add an additional workload to the driving task. Given its increasing use in driving research, investigating the impacts on driving performance is a key research question.
We thought we would use ORCa to test this. Our study involved participants driving ORCa around a pre-determined route close to the University of the Sunshine Coast, twice whilst providing a continuous verbal protocol, and twice with no requirement to verbalise their behaviour. We then analysed key aspects of driving performance across the conditions.
The findings were compelling. Based on a comparison of participants’ drives when providing a concurrent verbal protocol and when not, the findings showed that when driving mid-block, there was no impact on aspects of driving behaviour such as speed, speed variability, and steering wheel angle, but that there appeared to be a positive effect on braking and acceleration when approaching and exiting roundabouts.
You can use the link below to gain free access to the full article below. Here we discuss the study and its findings in more detail.