Truck mounted attenuators (TMAs) are a form of mobile crash cushion that are deployed on trucks to help shield and protect workers involved in a roadway maintenance activity from errant vehicles that enter the work zone. Because these TMAs are designed to be on the upstream end of the work zone, the drivers of these trucks are at greater risk of being involved in a crash. To mitigate this risk, the Colorado Department of Transportation has launched an autonomous TMA truck that is also referred to as an Autonomous Impact Protection Vehicle (AIPV). The AIPV is equipped with a TMA and follows a manned lead vehicle. The lead vehicle transmits position, heading, and speed to the AIPV, and the AIPV matches speed and follows the desired path. This advanced self-driving technology removes the need for a driver, thereby eliminating the associated danger and risk of injury in a crash.

Various operational aspects of the AIPV have been demonstrated. However, its response in an actual crash is unknown. What happens when the AIPV is hit from the rear while moving at a slow speed during a maintenance activity? How does the response of the driverless AIPV compare to that of a TMA truck with a driver? More specifically, do the brakes of the AIPV activate and does its forward motion stop?

The objective of this research is to perform a controlled full-scale crash test of the AIPV with TMA and determine its response. The AIPV with deployed TMA will be impacted by another vehicle from the rear while operating at a slow speed (5 to 15 mph). Brake activation and other factors of interest will be documented.

The crash test will be performed at an ISO 17025 certified test laboratory under controlled conditions. It is proposed to impact the TMA mounted to the AIPV while the AIPV is in motion using a 5,000-lb pickup truck design test vehicle as specified in the AASHTO Manual for Assessing Safety Hardware (MASH). The pickup truck will be instrumented with remote steering, throttle, and braking capability, and be steered into the TMA on the rear of the moving AIPV at an appropriate closing speed to test the actual crash reaction of the autonomous TMA truck.

A report will be generated that documents the details and results of the full-scale crash test. The test will verify the expected operation of the AIPV and protection of workers in an actual crash scenario. Video footage of the crash test will be provided.

The crash performance of the AIPV is a critical aspect of ensuring the expected safety performance of workers in the protected work zone. This research will support the advancement of autonomous maintenance technology by confirming the crash response and autonomous braking and stopping ability of the AIPV. The resulting test information will be immediately available and actionable by state agencies interested in deploying AIPVs with TMAs.