Extending Urban Multi-Lane Spatial Logic to Formalise Road Junction Rules

Abstract

During the design of autonomous vehicles (AVs), several stages should include a verification process to guarantee that the AV is driving safely on the roads. One of these stages is to assure the AVs abide by the road traffic rules. To include road traffic rules in the design of an AV, a precise and unambiguous formalisation of these rules is needed. However, only recently this has been pointed out as an issue for the design of AVs and the few works on this only capture the temporal aspects of the rules, leaving behind the spatial aspects. Here, we extend the spatial traffic logic, Urban Multi-lane Spatial Logic, to formalise a subset of the UK road junction rules, where both temporal and spatial aspects of the rules are captured. Our approach has an abstraction level for urban road junctions that could easily promote the formalisation of the whole set of road junction rules and we exemplarily formalise three of the UK road junction rules. Once we have the whole set formalised, we will model, implement, and formally verify the behaviour of an AV against road traffic rules so that guidelines for the creation of a Digital Highway Code for AVs can be established. * This research was supported by the German Research Council (DFG) in the PIRE Projects SD-SSCPS and ISCE-ACPS under grants no. FR 2715/4-1, FR 2715/5-1. BackgroundWe give preliminary information about the approach on formalising traffic rules using temporal logic from [3] in Sect. 2.1 and in Sect. 2.2, we present details on the abstract model and logic Urban Multi-lane Spatial Logic UMLSL from [29]. The Road Junction RulesIn the UK Highway Code there are different sections which handle the road traffic rules for Overtaking, Roundabouts, Road Junctions, among others [11]. Here we are concerned with the

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

“…For formalising spatial aspects of traffic rules, in previous work [20], we introduce the traffic logic Urban Spatial Logic for Traffic Rules (USL-TR). In this research preview, we focus on the temporal aspects of traffic rules.…”

“…We have captured the spatial elements of traffic rules using USL-TR (cf. [20]) and the sequential aspects using behaviour diagrams (cf. previous section).…”

“…In previous work [20], we introduced Urban Spatial Logic for Traffic Rules (USL-TR) for reasoning about traffic manoeuvres and rules at urban intersections. USL-TR is a spatial logic and is an extension of Urban Multi-lane Spatial Logic (UMLSL) that was introduced in [19].…”

“…For more details on USL-TR, we refer to [20]. Note that with the syntactical element >= size A , we leave the actual size size A of the safe gap for car A abstract at this point of the specification.…”

“…In this section, we showcase examples of how to extract behaviour diagrams from the UK Highway Code rules 170 and 171 [13]. For these two rules, we previously formalised their spatial aspects using USL-TR in [20]. In both rules, the overall goal of the AV is to safely enter a road junction.…”