Handbook of Driving Simulation for Engineering, Medicine, and Psychology

Traumatic Brain Injury

Abstract
The Problem. Very severe traumatic brain injury (TBI) can cause persistent functional limitations in visual-motor and cognitive functions which may have consequences for fitness to drive. On-road driving performance in this population is significantly related to performance on neuropsychological tests of attention and information processing. This particularly concerns basic “operational” driving tasks like brake reaction time, visual search time, and lateral position control (Van Wolffelaar, Brouwer and van Zomeren, 1990). Many drivers in this population, however, succeed in compensating effectively for these functional limitations, presumably because higher-order “tactical” aspects of driving allow them to anticipate and avoid driving situations which would be too demanding. Role of Driving Simulators. To be able to assess compensatory potential, two test drives in an advanced driving simulator are included in the neuropsychological assessment of fitness to drive. The tests and the context in which they are used are described. By means of three case studies with very severe TBI the additional value of the driving simulator tests is illustrated and discussed. Key Results of Driving Simulator Studies. Test drives in a driving simulator for the assessment of brain-damaged drivers have not yet been properly validated and standardized. As an addition to a neuropsychological examination, a driving test in a realistic driving simulator can be a useful tool to assess (lacking) compensatory driving skill in brain-damaged drivers. Scenarios and Dependent Variables. In the Swing Drive we assess the operational skill of lateral position control and the tactical skill of controlling speed in response to changing motivation and operator capacities. The test requires steering at various speeds on a winding country road with alternating left-right curves and a continuous stream of traffic from the opposing direction. In various conditions the average lateral position, the standard deviation of lateral position, lane crossings left and right, and collisions with other traffic are computed. In the City Drive we use a city and route developed in research on intersection complexity and ADAS in older drivers (Davidse, 2007). We assess practical fitness to drive based on observation of speed choice, lateral and longitudinal position control, viewing behavior, gap acceptance, application of priority rules, etc. in a variety of road and traffic situations as they develop during the drive. Platform Specificity and Equipment Limitations. The simulator system of ST Software B.V. is used. It contains the design tools to create simulated road environments and the runtime modules required for real-time simulation. Simulation of traffic is based on ‘autonomous agents’ technology which models the simulated participants (i.e., all traffic surrounding the simulator driver) as self-governing intelligent objects that show natural and normative driver behavior.

Keywords
Traumatic Brain Injury, Driving, Fitness to Drive, Driving Simulator, Rehabilitation

Key Points
• Severe traumatic brain injury (TBI) impairs information processing functions required for driving, thus posing a potential limit to fitness to drive. It is argued that this particularly concerns the operational level.
• Some severely impaired drivers with TBI effectively compensate by adapting the driving task on the tactical level. They realize practical fitness to drive by adapting driving skill and driving behavior in such a way that time pressure and the need for divided attention are reduced.
• Conventional neuropsychological assessment puts most emphasis on demonstrating impairment instead of on potential for rehabilitation and recovery. It is illustrated with case studies that driving simulator tests can redress this bias, at least if they can realistically tap into the tactical level of the driving task.

Web Resources
Web Figure 50.1: View from the mock-up in the Swing Drive (color version of Figure 50.1)

Readers are also directed to the Driving Simulators in Rehabilitation web site to view the test drives discussed in this chapter:
http://www.driving-simulator-rehabilitation.com/

Key Readings
Brouwer, W. H., and Withaar, F. K. (1997). Fitness to drive after traumatic brain injury. Neuropsychological Rehabilitation, 7(3), 177–193.

Coleman-Bryer, R., Rapport, P., and Hanks, R. A. (2006). Determining fitness to drive: Neuro-psychological and psy-chological considerations. In J. M. Pellerito, Jr. (Ed.), Driver rehabilitation and community mobility (pp. 165–184). St Louis, MO: Elsevier Mosby.

McKenna, P., Jefferies, L., Dobson, A., and Frude, N. (2004). The use of a cognitive battery to predict who will fail an on-road driving test. British Journal of Clinical Psychology, 43, 325–336.