Audi, BMW, Daimler, and General Motors are leading the way toward autonomous driving, according to a new study from Navigant Research.

Fully automated vehicles that operate themselves with no driver present "are still a decade away," according to Navigant. Yet, automakers will begin adding the "incremental systems necessary as a foundation for the related technology" in the next five to 10 years.

Navigant ranked each of 18 vehicle manufacturers according to several criteria and, based on their scores, grouped them into ranked categories.

After the Leaders group of four, Navigant ranked Contenders including Volvo, Ford, Toyota and Honda. The Challengers group included Nissan, Jaguar Land Rover, Tesla and Hyundai/Kia. The last group included Fiat Chrysler, Mazda, Renault, PSA Peugeot Citroen and Mitsubishi.

"Our approach looked at the overall strategy and execution to see who’s got the best history in this area as well as who's got the most on the drawing board now and has made announcements about what is going to be launched in the next year or two," David Alexander, London-based senior research analyst for the market research and consulting firm based in Boulder, Colo.

Read the full Navigant report here.