Synergizing the Safe System Approach, Safe System Pyramid and TSMO: Safe Operations System (SOS)

Abstract: According to FHWA, Transportation Systems Management and Operations (TSMO) is a suite of strategies, activities, and mobility services designed to optimize the performance of existing transportation systems. TSMO facilitates more efficient use of transportation infrastructure, aligns travel demand with system capacity more effectively, and offers integrated and comprehensive solutions that can usually be implemented quickly and at a lower cost compared to traditional capacity expansion. The benefits of TSMO include improved safety, smoother and more reliable traffic flow, reduced congestion, real-time highway and transit traveler information, and enhanced environmental conditions. Connecting Transportation Systems Management and Operations (TSMO) with safety is crucial because the strategies used in operations to enhance travel efficiency and reliability can directly impact traffic safety, and vice versa. Integrating these programs allows for the reduction of roadway crashes, injuries, and fatalities. Key strategies include monitoring through traffic management centers, optimizing real-time traffic signal timing, managing road weather conditions, and implementing variable speed limits—all of which contribute to safer and more efficient mobility. This paper introduces the Safe Operations System (SOS), a comprehensive framework that integrates the Safe System Approach (SSA) and the Safe System Pyramid with Transportation Systems Management and Operations (TSMO) strategies to improve road safety outcomes. The SOS framework aligns key elements of the SSA Wheel—focusing on safe road users, safe roads, safe vehicles, safe speeds, and post-crash care—with the structured interventions of the Safe System Pyramid, which encompasses education, active and latent safety measures, built environment, and socioeconomic factors. By leveraging real-time TSMO solutions, including traffic management, signal optimization, and incident response, the SOS framework optimizes the implementation of safety strategies to reduce crashes, injuries, and fatalities. The paper also proposes an enhancement to the CMM by integrating safety as a core dimension, enabling transportation agencies to systematically assess, prioritize, and improve their safety maturity levels. The enhanced CMM, guided by SOS, allows for targeted resource allocation in areas with lower safety and equity maturity, fostering a data-driven approach to achieve Vision Zero and improve equitable access to safe transportation. Through performance metrics focused on safety and equity, the framework facilitates continuous improvement and reinforces the strategic alignment between safety interventions and operational efficiency, ultimately contributing to safer, more resilient transportation systems.