This article presents solutions to challenges in using a low-density flash lidar for application to a heavy road vehicle Autonomous Emergency Braking (AEB) system. Low-density flash lidars are relatively new to the commercial market and are much less expensive compared to point-cloud lidars. However, due to their low angular resolution, it becomes challenging to use the information provided by them for applications such as the AEB. Specifically, the challenges in identifying relevant targets and determining target width are discussed in this article, and solutions to the same are presented. Later, an AEB algorithm is developed for a heavy commercial road vehicle for demonstrating the usefulness of the proposed solutions. The AEB system is experimentally evaluated using a brake Hardware-in-loop system along with IPG TruckMaker, and the results are presented.