Are low-speed automated vehicles ready for deployment? Implications on safety and urban traffic

• Low-Speed Automated Driving (LSAD) systems are currently being tested in many European cities. • Relatively little is known on the performances of existing LSAD systems and their impacts. • By testing a LSAD system on a proving ground, this study wants to cover this research gap. • Results show that existing systems still show a relatively low level of maturity. Urban shuttles in the form of Low-Speed Automated Driving (LSAD) systems have been already introduced in many European cities, mostly as part of demonstrations or pilot test campaigns. They are the result of several years of development and are expected to be reasonable candidates for commercial deployment in the near future. Usually, the Operational Design Domain (ODD) of LSAD vehicles is restricted in several aspects, eliminating a vast amount of foreseeable critical cases. Nonetheless, the mixed traffic scenarios of the urban environment still expose them to a wide variety of unsafe situations, where in particular the interaction with Vulnerable Road Users (VRUs) remains a critical aspect. Yet, deployment of LSAD vehicles on public roads may induce unsafe driving behavior of other road users, because they are perceived not to drive in an effective and dynamic manner. LSAD driving behavior might also negatively affect urban traffic efficiency in a mixed road user environment. For these reasons, this paper presents the results of a dedicated experimental campaign aimed at characterizing the performances of one of the LSAD vehicles commonly used in European demonstration projects. The aim is to to assess their current capabilities and draw inferences about the potential effects they may have on road safety and traffic dynamics. The assessment is believed to be valid generally, because the vehicle used throughout the test campaign represents the state of the art of LSAD vehicles regarding perception, localization, vehicle control, transmission, driving dinamics and finally the safety concept. Undertaking a performance evaluation of LSAD vehicles is not straightforward. In this work, we suggest using relevant requirements from the EU Type Approval Regulation for Automated Driving Systems EU 1426/2022. While those are originally devised to give the relevant authority a binary (pass/fail) result, we show how selected provisions can be used as an assessment methodology that can provide additional insights on a complex problem. There was no aim to prove regulatory compliance or non-compliance, but rather to test the technology readiness level of the systems tested around Europe. The results showed the limited capabilities of these vehicles compared to the minimum safety level required by the regulation. This suggests that development is still needed for these types of LSAD vehicles to achieve a generally accepted safety level.