One of the concerns with autonomous vehicles is their ability to communicate their intent to other road users, specially pedestrians, in order to prevent accidents. External Human-Machine Interfaces (eHMIs) are the proposed solution to this issue, through the introduction of electronic devices on the exterior of a vehicle that communicate when the vehicle is planning on slowing down or yielding. This paper uses the technique of unwrapping the faces of a mesh onto a texture where every pixel is a unique color, as well as a series of animated simulations made and ran in the Unity game engine, to measure how many times is each point on a 2015 Ford F-150 King Ranch is unobstructed to a pedestrian attempting to cross the road at a four-way intersection. By cross-referencing the results with a color-coded map of the labeled parts on the exterior of the vehicle, it was concluded that while the bumper, grill, and hood were the parts of the vehicle visible to the crossing pedestrian most often, the existence of other vehicles on the same lane that might obstruct the view of these makes them insufficient. The study recommends instead a distributive approach to eHMIs by using both the windshield and frontal fenders as simultaneous placements for these devices.

翻译：自动驾驶汽车的一个关注点在于其向其他道路使用者（尤其是行人）传达意图的能力，以防止事故的发生。外部人机界面（eHMIs）是通过在车辆外部引入电子设备来传达车辆计划减速或让行意图的解决方案。本文采用将网格面展开到纹理上的技术（其中每个像素具有唯一颜色），并结合在Unity游戏引擎中制作和运行的一系列动画模拟，以测量在四向交叉路口试图过马路的行人面前，2015款福特F-150 King Ranch车型上每个点未被遮挡的次数。通过将结果与车辆外部标记部件的颜色编码地图进行交叉比对，得出结论：虽然保险杠、格栅和发动机盖是过路行人最常看到的车辆部件，但同车道其他车辆可能遮挡这些部件的视线，使其不足以作为唯一展示位置。研究建议采用分布式方法设置eHMIs，即将挡风玻璃和前翼子板同时作为此类设备的安装位置。