Mack Road Stability Advantage by Bendix (RSA) with Adaptive Cruise Control (ACC) is a new approach to adaptive cruise control that helps avoid collisions by integrating throttle, engine brake, and foundation brakes into the cruise control function. The company made the announcement during the Mid-America Trucking Show, which was held March 19-21 in Louisville, Kentucky.
“Cruise control is a great feature for highway driving, since it can reduce driver fatigue and improve fuel economy,” said Jerry Warmkessel, Mack marketing product manager-highway products. “But traffic conditions can change quickly from slowing vehicles or close cut-ins by other vehicles. Mack RSA with ACC not only alerts the driver when the distance to the vehicle in front changes, it also takes action to maintain a safe following distance at the new speed.”
Mack's ACC uses a radar sensor mounted behind the front bumper to identify and track moving objects in front of the truck. Once the driver turns the cruise control on and sets the speed, ACC works to maintain a set time gap behind the vehicle in front. Indicators are integrated into the dash, so there are no extra displays to distract the driver.
If the vehicle ahead slows and the time gap starts to decrease, ACC will in sequence reduce throttle to the engine, apply the engine brake and, finally, apply the foundation brakes. The system applies about one-third of foundation brake capacity, which means the driver always has the capability to apply full braking force.
The default time gap is 2.8 seconds, which equals 246 feet at 60 miles per hour. Drivers have the ability to set other time gaps with an optional distance switch. Once the vehicle ahead increases speed and resumes a safe distance, ACC automatically resumes its set speed.
Mack RSA with ACC provides several distinctive types of audible alerts to the driver, including for decreased following distance and close cut-ins by other vehicles (such as when another vehicle changes lanes too close to the front of the truck), plus an impact alert. The following distance and close cut-in alerts are always active, even with cruise control turned off. The zone for the cut-in alert is approximately 20 feet in front of the truck. Since ACC builds on the Mack RSA platform, full stability control is always active, which provides stability interventions as needed.