Transport safety & accident prevention
Guidelines for conducting intersection safety audits that identify signal, geometry, and signage improvements to reduce crashes.
A systematic approach to evaluating intersections combines signal timing, lane geometry, and clear signage to uncover safety gaps, prioritize improvements, and reduce crashes through data-driven, practical interventions.
Published by
Jerry Jenkins
July 18, 2025 - 3 min Read
In many communities, intersections represent a focal point for crashes, conflicts, and near misses. A structured safety audit examines how drivers, pedestrians, cyclists, and transit users interact within the intersection space and how traffic control devices influence behavior. The process begins with assembling a diverse team that includes engineers, planners, law enforcement, and community representatives. A comprehensive site visit documents operating conditions, sight distances, turning radii, pedestrian crossings, and curb ramps. The audit should consider nearby land uses, driveways, transit stops, and potential distraction factors. By combining field observations with historical crash data, the team builds a factual picture that clarifies which aspects most deserve attention and immediate action.
After data collection, the audit shifts toward identifying concrete opportunities for improvement. Each potential action is evaluated against a consistent set of criteria: expected crash reduction, implementation feasibility, cost, disruption to current traffic, and alignment with local policies. The team pays particular attention to signal timing, phasing, and coordination, as mis-timed sequences often compound turning conflicts and pedestrian risk. Geometry issues such as tight curb radii, inadequate lane widths, or confusing lane markings are assessed for their contribution to abrupt vehicle maneuvers. Signage clarity, visibility, and consistency are reviewed to ensure drivers can interpret guidance quickly under varied lighting and weather conditions.
Practical geometry and clear signaling reduce confusion and risk for all users.
The first category to scrutinize is signal operations. Auditors examine cycle lengths, progression, and the presence of pedestrian-friendly phases. They assess whether phases provide adequate time for crossing pedestrians, particularly for seniors and individuals with mobility aids. They also consider the spacing of signals along arterials to avoid split phases that force abrupt acceleration or deceleration. In planning alternatives, the team weighs adaptive timing versus fixed schedules, recognizing that adaptive systems can respond to real-time conditions but require maintenance and calibration. Any proposed change should reduce red-light violations while preserving traffic flow and access for all modes.
Geometry and intersection design form the second critical area. Auditors look for conflicts created by turning movements, sight line obstructions, and inadequate meshing of crosswalks with drive lanes. They evaluate whether island configurations, bumpouts, or channelized turns better separate movements and shorten pedestrian exposure. Signalized intersections may benefit from updated lane markings that reduce lane confusion at high-volume periods. Additionally, curb radii can be adjusted to balance vehicle maneuverability with pedestrian safety. The audit considers construction implications, maintenance requirements, and long-term durability of any geometric changes to ensure lasting benefits.
Engagement, monitoring, and adaptation sustain long-term safety gains.
Signage and pedestrian guidance are essential complements to signals and geometry. The auditors test whether signs use consistent terminology, familiar symbols, and legible fonts at appropriate heights and distances. They check that crosswalks, yield lines, and stop bars are visible during dawn, dusk, and rain. The placement of signs relative to drivers’ sight lines and the presence of glare guards or reflective materials are evaluated. In many cases, adding prominent advance warning signs, in-road wayfinding, or enhanced curb ramp markings can significantly improve comprehension for unfamiliar drivers or visitors. The overarching goal is intuitive guidance that reduces hesitation and incorrect assumptions.
The team also considers non-monetary factors that influence safety outcomes. Community drivers may rely on certain routes during peak hours, while pedestrians may have limited crossing opportunities near schools or transit hubs. Building trust through transparent communication helps residents understand why improvements are proposed and how they will be implemented. Public engagement sessions, combined with clear visual simulations, can reveal concerns that technical analyses might overlook. Finally, audits should include a plan for monitoring post-implementation results and adjusting strategies as data reveals effectiveness over time.
Clear, implementable plans with measurable outcomes guide success.
A practical audit report organizes findings into prioritized action packages. Each package includes a concise problem statement, the proposed solution, anticipated crash reductions, cost ranges, and a realistic timeline. Decision makers benefit from a clear, quantified rationale that links improvements to specific safety metrics, such as reductions in angle crashes or pedestrian conflicts. The report should also note any potential equity considerations, ensuring that improvements do not disproportionately benefit one group at the expense of others. Clear ownership assignments and responsible parties help accelerate project advancement through procurement, design, and construction phases.
In addition to technical readability, the audit must align with local planning goals and budget cycles. A well-structured plan identifies quick wins—low-cost, high-impact changes that can be implemented promptly—alongside longer-term investments that may require capital funding. It is important to anticipate maintenance needs, such as repainting traffic lines, replacing worn pavement symbols, and updating signal hardware. The audit should also describe potential temporary traffic management plans during construction to minimize disruption. Stakeholders gain confidence when the plan demonstrates transparency about trade-offs and expected performance outcomes.
Documentation and replication strengthen safety audits and future-proof changes.
Beyond the immediate intersection, audits should consider the broader corridor context. How do adjacent intersections interact with a given site, and could coordinated signal timing create network-wide safety benefits? Evaluators assess whether improvements on one corner would create new hazards downstream if not paired with other adjustments. A holistic approach often reveals synergies, such as synchronized pedestrian phases across multiple crossings or shared curb extensions that reduce crossing distance. Corridor-level strategies can also support safe multimodal transitions, encouraging walking and cycling by improving perceived safety and comfort.
The technical appendix of the audit includes data sources, methodologies, and assumptions. Documentation should specify crash types, time-of-day patterns, and exposure estimates for pedestrians and vehicles. The appendix also lists all field observations, photographs, and measurements taken during the site visit. A transparent methodology enables independent review and future replication as traffic patterns evolve. To maximize usefulness, analysts should present sensitivity analyses showing how results might shift under different traffic volumes or weather scenarios.
Implementation planning is a collaborative process that requires coordination across departments. Engineers, city planners, public works crews, transit agencies, and law enforcement must align on approvals, funding, and timelines. The audit can serve as a governance tool, guiding design reviews, permits, and safety campaigns. It is equally important to prepare a stakeholder communications plan that explains anticipated benefits, addresses concerns, and highlights how improvements support vulnerable road users. By embedding accountability and clear milestones, the audit transitions from paper to practice with measurable impact on crashes and injuries.
Finally, measuring effectiveness after implementation closes the loop. Post-installation audits and ongoing monitoring verify whether targeted crash reductions materialize and whether any adjustments are needed. Data collection should continue at defined intervals, capturing near-miss reports, compliance with new signals, and user feedback. When results fall short of expectations, teams revisit assumptions, refine timing plans, or upgrade signage for clarity. Through iterative evaluation, communities cultivate safer intersections and build a culture of proactive safety that endures as traffic patterns evolve.
