Determining the impact that a medication may have on driving ability is an important safety determination in clinical trials, particularly for drugs that affect that central nervous system (CNS). While several different methods have been developed over the years, driving simulation studies – with the option of an integrated protocol that includes neuropsychological testing – offer the advantage of accuracy, flexibility, and cost-effectiveness, in a safe testing environment.

Why measure driving ability?

With well over a billion cars on the road worldwide, preventing traffic accidents resulting from drug-impaired driving is an important public health priority.

While driving tests are useful for keeping people who take certain drugs off the road, they can also help to keep them on the road. The need for broad restrictions is eliminated when drugs that may cause problems are identified through testing, allowing for more targeted regulations. This contrasts with countries, like Japan, where driving is prohibited for anyone taking medications known to affect the CNS, regardless of whether or not they actually impair driving ability.

How is driving ability measured?

The potential for a drug to impact driving ability can be measured in several ways: real-world, on-the-road assessment, neuropsychological testing (e.g., reaction times, psychomotor speed, and processing), and driving simulation.

Real-world assessment is accurate for the given set of conditions being evaluated. However, it may not be feasible to evaluate drivers under all relevant conditions. Certain situations may be too dangerous, or otherwise unethical, to test. High traffic, low light, road obstacles, or specific weather conditions may not be accessible, or can be difficult to control. In addition, real-world assessment is expensive and time-consuming, and may be stressful for the tester.

Neuropsychological testing uses variables such as visual perception, verbal distraction, memory, cognitive flexibility, and daytime sleepiness as predictors. This method is useful in early evaluations of potential impairing and enhancing effects. In some cases, such data may be helpful to rule out drugs that lack impairing or enhancing effects and therefore may not require further testing. However, for drugs that do show effects, accuracy and reliability can be limited when used on its own, often warranting the need for a dedicated driving study.[i]

The need to measure driving ability, along with technological advances and the limitations of alternative methods, have led to the need for driving simulation as an indispensable tool for clinical trials. This process has the advantage of allowing testing under a variety of conditions, while also being less costly, faster, and safer than real-world testing. There is no risk of property damage or injury, and it offers a high degree of validity, with the related advantage that conditions can be controlled and repeated. Driving simulation can also be combined with neuropsychological testing to obtain an ideal mix of complementary information from each method.  

When is driving simulation needed?

Driving simulation is appropriate for:

  • New drugs
    • To be administered during the day
    • To be administered at night in case of any residual effects
    • Intended for chronic usage
    • CNS-impairing drugs
    • CNS-stimulating drugs because of the potential for risk-taking behaviors
  • Existing drugs
    • For a different application
    • To be administered in a different dose
    • To be given according to a new dosing schedule
    • In a new patient population

The FDA and your CRO should be involved early on in your drug development process to help you plan and design your testing protocol.

Why Partner with Altasciences?

Altasciences has extensive experience conducting driving simulation studies, with over 13,000 drives completed at our clinical facilities to date. Our experts can help you strategically navigate whether or not you may need dedicated driving studies, and support waiver requests for drugs that may qualify. We have a suite of 12 state-of-the-art driving simulators and a participant database of 350,000, with additional access to patients and other special populations through our collaborative relationships with hospitals and clinics. We offer professional oversight by certified, driving simulation specialists; and through our partnership with Cognitive Research Corporation (CRC), we have the ability to combine driving simulation with neuropsychological tests for optimal testing validity.

Contact our experts today to discuss your driving simulation needs.

You may be interested in:

Driving Simulation Studies

FDA Finalizes Drug-Impaired Driving Guidance, Leading to Additional Studies on the Effects of Drugs on Driving