The divergence in traffic sign symbol systems and regulatory frameworks between China and its ASEAN land neighbors (Vietnam, Laos, and Myanmar) has emerged as a critical bottleneck for regional transport connectivity under the Belt and Road Initiative. From the perspective of transportation integration, this paper systematically examines the classification logic, visual symbol design, and regulatory standards of traffic signs across the four nations. The paper identifies the structural causes and implications of these disparities through comparative analysis. Empirical findings indicate that historical path dependence, geographical constraints, fragmented governance mechanisms, and cultural cognitive differences are the primary determinants of these systemic variances. These discrepancies impede cross-border drivers’ information processing efficiency, leading to elevated accident rates and logistics inefficiencies. To address these challenges, the paper proposes three key strategies: establishing a regional standardization cooperation framework, implementing phased bilingual sign pilot programs, and leveraging advanced technologies for dynamic information signage. These recommendations aim to provide both theoretical underpinnings and actionable pathways for enhancing cross-border transportation safety, optimizing port clearance processes, and advancing the overarching goal of China-ASEAN transport integration.