Field testing of Automatic Emergency Braking (AEB) systems using real actual heavy trucks and buses is unavoidably limited by the dangers and expenses inherent in crash-imminent scenarios. For this paper, a heavy vehicle is defined as having a gross vehicle weight rating (GVWR) that exceeds 4536 kg (10,000 lbs.). High fidelity Hardware-in-the-Loop (HiL) simulation systems have the potential to enable safe and accurate laboratory testing and evaluation of heavy vehicle AEB systems. This paper describes the setup and experimental validation of such a HiL simulation system. An instrumented Volvo tractor-trailer equipped with a Bendix Wingman Advanced System, including the FLR20 forward looking radar and AEB system, was put through a battery of different types of track tests to benchmark the AEB performance. Two heavy vehicle crash scenarios were tested: (1) Slower-moving lead vehicle scenario, where the subject vehicle’s AEB detects and responds to a vehicle moving more slowly in its immediate forward path (“lead vehicle”), and the (2) Decelerating lead vehicle scenario, where the lead vehicle suddenly decelerates in the path of the subject vehicle. These tests were then performed on the HiL simulation system using the same type of Bendix Wingman System and radar, and the results were compared.