Various Vulnerabilities in Highway Hierarchies: Applying the UK Highway Code’s Hierarchy of Road Users to Autonomous Vehicle Decision-Making

Abstract

In 2022 the UK government introduced extensive updates to the Highway Code. This includes making specific reference to autonomous vehicles (AVs) on UK roads as a present reality, as well as providing a clear 'hierarchy of road users.' This order of road users is based on the code's understanding of their relative vulnerability and, therefore, their need for protection. In the context of AVs and crash scenarios, the subject of relative value among road users has arisen - often in the form of trolleyology. Considering the new code offers a simple approach to this question, with a clear hierarchy of users, it may be argued that the code goes some way to address the public's concern. This article explores the new code, its approach of using vulnerability to create a hierarchy of road users, and its implications for programming AVs in crash scenarios.