This report examines the potential costs and benefits of Intelligent Speed Adaptation (ISA) in Australia. Analysis was conducted to determine the benefits of advisory, supportive and limiting ISA. This analysis suggested advisory ISA would reduce injury crashes by 7.7% and save 1,226millionperyear.Thesefigureswere15.12,240 million for supportive ISA and 26.4% and $3,725 million for limiting ISA. A cost benefit analysis was conducted considering different implementation scenarios including: all vehicles, new vehicles, fleet vehicles, market driven, heavy vehicles, young drivers and navaid devices. The cost benefit analysis was heavily influenced by the unit price of the ISA devices causing the cost benefit ratios (BCRs) to vary from as low as 0.29 to 4.03 over a 20 year timeframe. The “all vehicles” and “new vehicles” scenarios produced the greatest BCRs although it was thought that, taking into account the elevated risk of young drivers, a combination of implementing ISA on young driver’s vehicles and new vehicles may be the most cost effective implementation scenario. Limiting ISA generally produced the highest BCRs therefore this level of ISA should be implemented wherever possible.SD Doecke, JE Woolleyhttp://www.roadsafetyconference2010.com.au/index.htm