Safe System Research and Implementation: Final Report

Banerjee, Ipsita; Luo, Qianhua; Champlin, Jacob; Griswold, Julia; Mitman, Meghan · 2025 · ROSA P / University of California, Berkeley. Safe Transportation Research and Education Center

archive: archived pipeline: cataloged verified

Get this paper ↗ (full text — opens at the source; we link to it, we don't host it)

Summary

This report addresses the critical need to reduce fatal and serious injury (FSI) crashes in California, which increased by 51.9% over the past decade. Motivated by Director’s Policy 36, which mandates the adoption of the Safe System Approach (SSA) to achieve Vision Zero by 2050, the study aims to operationalize SSA principles within the California Department of Transportation (Caltrans). The research focuses on defining SSA from Caltrans’s perspective, evaluating the alignment of existing programs, assessing specific safety countermeasures, reviewing training curricula, and developing tools for kinetic energy risk assessment. The methodology involved a comprehensive review of literature, data analysis, and the development of new frameworks and tools. Researchers evaluated the alignment of Caltrans programs using a Program Evaluation Method and a Project Evaluation Method based on the Austroads Safe System Matrix. They conducted detailed assessments of cable barriers and roundabouts as SSA-aligned countermeasures, analyzing their applicability to the State Highway System through interviews with engineers and literature reviews. Additionally, the team developed a Caltrans Safe System Framework, created training materials including a 90-minute module and a 6-hour curriculum, and constructed a spreadsheet-based model for intersection kinetic energy assessment based on the Federal Highway Administration’s Safe System for Intersections (SSI). Key findings include the identification of significant obstacles and opportunities for implementing cable barriers and roundabouts. Cable barriers were found to substantially reduce FSIs by absorbing crash energy, though concerns regarding vehicle deflection on narrow medians and high maintenance requirements necessitate pilot installations and specification updates. Roundabouts were confirmed to reduce conflict points and crash severity, with recommendations for broader implementation and inclusive design modifications. The study also produced the Caltrans Safe System Framework, which prioritizes interventions based on roadway context and effectiveness, ordering strategies from reducing exposure and speeds to improving vehicle safety and post-crash care. Furthermore, the review of existing training programs revealed a need for better integration of SSA principles, leading to recommendations for embedding SSA modules in foundational courses. The significance of this work lies in providing a structured roadmap for institutionalizing the Safe System Approach at Caltrans. By offering specific evaluation methods, countermeasure guidelines, and educational resources, the report enables Caltrans to systematically reduce kinetic energy and crash risk across the state. The development of proactive risk assessment tools and the emphasis on equity in safety planning support the broader goal of eliminating FSI crashes. These contributions facilitate a shift from reactive safety measures to proactive system design, ensuring that roadway infrastructure accommodates human vulnerability and promotes safer outcomes for all road users, particularly vulnerable populations.

Key finding

The report establishes a Caltrans Safe System Framework and identifies cable barriers and roundabouts as effective countermeasures for reducing kinetic energy and crash severity, while recommending updates to training and proactive risk assessment tools to align with Vision Zero goals.

Methodology

review

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed. Discovered via bulk_ingest_rosap on 2026-05-23 (6 acquisition events logged).

Summary generated by qwen3.6-27b-prismaquant on 2026-06-10; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• incidence prevalence
• comparative international
• regulatory evaluation
• cyclist safety
• perceptual countermeasures
• induced exposure

Information type

What kind of knowledge this paper contributes, grouped by family — independent of topic (what it is about) and method (how it was studied).

• Applied Guidance: countermeasure evaluation
• Empirical Findings: crash risk outcomes
• Methodological Resource: dataset resource