The increasing density of vehicles on roads has raised concerns for transportation system safety and convenience. To mitigate accident and congestion risks, integrating advanced vehicular and communication technologies has facilitated the development of vehicular ad-hoc networks (VANETs). These networks enable vehicles to share real-time safety alerts with other vehicles and traffic authorities. However, open wireless links in VANETs are susceptible to security threats, making the authentication and integrity of transmitted safety alerts essential. Yan et al. addressed these needs with a hierarchical authentication scheme (IEEE Trans. on Veh. Tech., vol. 73, no. 1, 1253–1262, 2023). Unfortunately, the devised study identifies vulnerabilities in Yan et al.’s design, specifically concerning forgery and anonymity exposure attacks. In response, an improved, secure hierarchical authentication scheme is proposed. Through both formal and informal security analyses, it is demonstrated to be resilient against various practical attacks. A thorough performance evaluation further supports the design's practical suitability for deployment within VANET infrastructure, offering enhanced security for safer transportation networks.