Development of a Test of Planning Abilities of Drivers in a Driving Simulator

Abstract

Introduction

As individuals age, there is a notable decline in executive functions, which significantly affects driving performance among older adults. Planning, an essential executive function, is defined as "the organization ahead of time of goal-directed behaviors" [1]. The Tower of London (ToL) test is widely used to evaluate the planning abilities of elderly drivers as an indicator of their overall executive functioning and, by extension, their capacity to drive safely. The test consists of three pegs of varying length and three balls, which are placed on the pegs. Participants are shown the goal state and tasked with preplanning and executing a sequence of moves to reach it. Variables measured include the number of trials solved, number of moves, preplanning time and movement time. The present study aims to adapt the Tower of London (ToL) test for driving simulator use as it offers a more valid and reliable measure by simulating the complex, dynamic, and multitasking environment encountered on the road. Based on the literature, we concluded that to mimic the results of the ToL, the new test in a driving context must not be excessively complex, and the number of “moves” or turns in the scenario should not exceed 7 [2].

Test scenario

The test will involve three progressively complex scenarios where participants are required to use a driving simulator to navigate through a simulated urban environment designed to mimic real-world streets and traffic conditions. Each scenario will incorporate specific navigational rules, for example the necessity to pass through at least one roundabout, avoid parks, and selecting the shortest possible route. In the first phase of the task, participants' preplanning time and the effectiveness of their initial route selection will be assessed. The next phase involves participants driving through the simulation. During this phase, one of the pre-selected streets will be unexpectedly closed. This will necessitate an on the spot re-routing, allowing for the evaluation of the participants' on-line planning abilities. 

Implementation and Future application

Participants would progress from easy to more challenging scenarios based on their performance. Results would be compared with their performances on the ToL test across three difficulty levels. Correlations in time taken, planning effectiveness, and errors made in both tasks would be analyzed. If the test demonstrates correlation with the ToL test, it could become an essential tool in the driver's license renewal process for elderly individuals and those with neurological impairments, transcending traditional neuropsychological assessments by evaluating planning skills in contextually relevant settings (while driving) which offers a more accurate reflection of real-world driving capabilities in relation to an individual’s executive functions.

References

[1] R. Le Bouc et al., “Anatomy and disorders of frontal lobe functions: Higher-order functions,” Encyclopedia of Behavioral Neuroscience, 2nd edition, pp. 280–288, 2022. doi:10.1016/b978-0-12-819641-0.00066-9

[2] J. M. Unterrainer et al., “Planning abilities and the Tower of London: Is this task measuring a discrete cognitive function?,” Journal of Clinical and Experimental Neuropsychology, vol. 26, no. 6, pp. 846–856, Sep. 2004. doi:10.1080/13803390490509574