Instead of taking the control away from humans, Toyota decided to use the autonomous driving technologies to ‘assist’ the driver doing a better job of driving. By taking some of the load off the driver, Toyota reckons they can make driving safer and less tiring.

The Automated Highway Driving Assist (AHDA) was designed for this purpose. In essence, it is an adaptive Cruise Control, which wirelessly communicates with preceding vehicles to maintain a safe distance. But it is mixed with Lane Trace Control, which aids steering to keep the vehicle on an optimal driving line within the lane. Mercedes is currently using a similar system capable of steering the car in some of their new models.

Toyota’s system does not rely on a radar-based cruise control. Instead, its Cooperative-adaptive Cruise Control uses 700-MHz band vehicle-to-vehicle ITS communications to transmit acceleration and deceleration data of preceding vehicles so that following vehicles can adjust their speeds. Lane Trace Control is where the autonomous technology shows itself by controlling the vehicle’s steering angle, driving torque and braking force when necessary to maintain the optimal line within the lane.

Toyota Automated Highway Driving Assist System will soon start real world testing on the Shuto Expressway near the Tokyo metropolitan area starting October 15. Before that it will be showcased at the 20th Intelligent Transport Systems World Congress Tokyo 2013.