Towards a Digital Highway Code using Formal Modelling and Verification of Timed Automata

TL;DR

This paper proposes a formal approach to model and verify traffic rules for autonomous vehicles using timed automata and a specialized traffic logic, aiming to establish a Digital Highway Code.

Contribution

It introduces methods to extract behavior diagrams from traffic rules and convert them into timed automata with formal logic, advancing towards verifiable autonomous traffic systems.

Findings

Formal representation of traffic rules using timed automata

Automated extraction of behavior diagrams from traffic rules

Integration of USL-TR logic into automata guards and invariants

Abstract

One of the challenges in designing safe, reliable and trustworthy Autonomous Vehicles (AVs) is to ensure that the AVs abide by traffic rules. For this, the AVs need to be able to understand and reason about traffic rules. In previous work, we introduce the spatial traffic logic USL-TR to allow for the unambiguous, machine-readable, formalisation of traffic rules. This is only the first step towards autonomous traffic agents that verifiably follow traffic rules. In this research preview, we focus on two further steps: a) retrieving behaviour diagrams directly from traffic rules and b) converting the behaviour diagrams into timed automata that are using formulae of USL-TR in guards and invariants. With this, we have a formal representation for traffic rules and can move towards the establishment of a Digital Highway Code. We briefly envision further steps which include adding environment and agent models to the timed automata to finally implement and verify these traffic rule models using a selection of formal verification tools.