Queensland ACC Systems May Not Meet Safe Following Distances

Adaptive cruise control (ACC) systems in many of the most popular cars in Queensland might not adhere to the State Government’s safe following distance recommendations, according to new research from the University of the Sunshine Coast.

The study, led by Dr Michelle Nicolls from the MAIC/UniSC Road Safety Research Collaboration, analysed 20 car manufacturers and found that only two had available settings that expressly followed Queensland guidelines for maintaining a safe following distance.

The Queensland Government recommends maintaining at least a two-second gap between a vehicle and the one in front. However, the majority of vehicle manuals explored in the study either did not specify what gap their ACC systems employed or used metres to describe gap distances, which may make it difficult for drivers to set their vehicles to comply with the guidelines.

Drivers relying on ACC to maintain a safe distance may be risking their safety and potentially breaking Queensland law if they are following too closely to the vehicle ahead.

“Drivers trusting their ACC system to maintain the correct following distance are not only risking their safety – they might be breaking Queensland law if following too closely to the vehicle in front,” Dr Nicolls said.

“It’s possible that many drivers aren’t aware of the discrepancy, given the lack of clarity and specifics listed in car manuals.”

The research also highlighted additional limitations of ACC technology. Many vehicle manuals recommend switching off ACC under poor driving conditions such as rain, fog and glare. However, previous research indicates that more than 50 percent of motorists continue to use ACC in such conditions despite manufacturer recommendations.

ACC is a feature in modern cars that adjusts a driver’s selected cruising speed to maintain a designated gap with the vehicle ahead. The technology is also noted to be limited in heavy congestion and frequent stopping-and-starting traffic.