Applying the Safe System Approach to Transportation Planning, Design, and Operations (2025)
Chapter: Safe System Pillars (Elements/Outcomes)
Safe System Pillars (Elements/Outcomes)
Safe Vehicles ensure drivers will not crash into people or objects with human-intolerable force via providing intelligent speed adaptation depending on the operating context, lane keeping, and automated emergency braking.
Safe Speeds are aligned with known human tolerances to closing/impact speed forces, varying speeds by the road and land use contexts, as well as road user mix.
Safe Roads are self-enforcing, automatically cueing drivers to engage in context-appropriate, desired behaviors, designed with energy absorbing protections (e.g., breakaway poles, see: Vardaki et al., 2014), and based on likely interactions of vehicles and users of different speeds, directions, and masses (Wegman et al., 2008).
Post-Crash Care is well-resourced, equipped with crash predictive capabilities, inclusive of next-gen 911 functionality, better able to access level 1 and 2 trauma centers across the country, and to be part of safety planning to improve crash scene management and prevent secondary crashes and injuries (Liu, 2022).
Safe Road Users are the desired result of a truly Safe System. They value, practice, and endorse safety regulations, electing policymakers partly on the latter’s evident safety-oriented platforms.
The next section introduces a framework to begin a concerted, coordinated effort to translate Safe System philosophy into tangible organization principles, as illustrated in Table 1.
Table 1. Proposed Organization Principles (adapted from Shi, et al., 2023).
| Principle | Definition |
|---|---|
| System operator responsibility | Assigns clear roles to system operators: engineers and planners should plan and design roads that minimize harm from crashes; vehicle manufacturers should design safer vehicles for all road users; and the public health sector should provide better injury surveillance, post-crash care, and trauma response to prevent traffic deaths. |
| Learning and innovating | Requires safety professionals and researchers to regularly examine crash contributors and the efficacy of implemented countermeasures toward iterating on approaches and continually improving practices and policies. The Plan–Do–Check–Act cycle: planning of road user protective measures based on the research on the most severe crashes (Plan); implementation of the protective measures (Do); evaluation of the safety performance and outcomes of the measures (Check); improvement of safety policy based on feedback (Act). The Plan–Do–Check–Act cycle is repeated continuously toward eliminating serious road trauma. |
| Vertical integration | Requires coordination and alignment of safety planning and programming across levels of government. |
| Horizontal integration | Requires coordination among road and street designers and land use planners and coding officials. |
