Abstract
<title>Abstract</title> <p>According to the Society of Automotive Engineers (SOA), intermediate levels of vehicle automation (Levels 2 and 3) are designed to operate only within a limited set of predefined Operational Design Domain (ODD). Outside these conditions, the driving system may no longer be able to safely manage the driving task and therefore requires the human driver to intervene through a Takeover Request (TOR) warning. TORs are designed to support drivers in regaining vehicle control; however, conventional warnings may not effectively guide attention towards relevant areas of the driving environment. Directional TORs have been proposed as a promising approach by providing spatial information about hazards or safe manoeuvring areas. Nevertheless, existing studies have reported inconsistent findings regarding their effects on takeover performance, including takeover time and quality. This systematic review and meta-analysis aims to synthesise empirical evidence on the effectiveness of directional TORs compared with non-directional TORs and to examine whether different directional strategies (towards-free-lane vs. towards-hazard) influence takeover outcomes. Furthermore, potential sources of heterogeneity across studies will be explored to clarify these inconsistent findings.</p>