How can you incorporate safety into traffic impact assessments?

1 Why safety matters

Safety is a fundamental aspect of transportation planning and design, as it affects the well-being, mobility, and accessibility of all road users. Safety also has economic and social impacts, as crashes and injuries impose costs on individuals, communities, and society. By incorporating safety into your TIAs, you can identify potential hazards, conflicts, and risks associated with the proposed development and its traffic generation, distribution, and assignment. You can also propose mitigation measures, such as traffic calming, signalization, signage, lighting, and geometric improvements, to reduce the likelihood and severity of crashes and enhance the safety performance of the transportation system.

2 How to assess safety impacts

To assess the safety impacts of a proposed development, you need to collect and analyze relevant data and information, such as existing and projected traffic volumes, speeds, and patterns; crash history and trends; road and intersection characteristics; pedestrian and bicycle facilities and demand; transit services and ridership; and land use and urban design features. You can use various methods and tools to evaluate the safety impacts, such as crash prediction models, conflict analysis, level of service, safety performance functions, and safety audits. You should also consider the safety impacts for different modes, scenarios, and time periods, and compare them with the baseline or no-build conditions.

3 How to report safety impacts

When reporting the safety impacts of a proposed development, you need to present your findings and conclusions in a clear, concise, and consistent manner. Your report should include a description of the proposed development, its location, size, type, and phasing; a summary of the existing and future transportation system and its safety performance; a description of the data sources, methods, and assumptions used for the safety analysis; a discussion of key safety issues, problems, and opportunities identified by the analysis; a list of recommended safety mitigation measures with their costs, benefits, and implementation responsibilities; a comparison of the safety impacts for the build and no-build alternatives; a sensitivity analysis or range of uncertainty for the safety impacts; and a summary of any limitations, challenges, and uncertainties of the safety analysis.

4 How to communicate safety impacts

To communicate the safety impacts of a proposed development, you need to engage with various stakeholders, such as the public, decision-makers, developers, and other agencies. You should use appropriate formats, media, and channels to convey your message and solicit feedback. You should also use clear and simple language, avoid technical jargon, and use visual aids, such as maps, charts, graphs, and photos, to illustrate your points. You should highlight the main safety impacts, the rationale and evidence for your recommendations, and the expected outcomes and benefits of the safety mitigation measures. You should also address any concerns, questions, or objections raised by the stakeholders and explain how they were considered or resolved.

5 How to improve safety analysis

When performing a safety analysis for TIAs, it's important to align your safety objectives and criteria with the relevant policies, standards, and regulations. You should use reliable and up-to-date data and information from credible sources, and apply appropriate and consistent methods and tools that suit the context and scale of the development and transportation system. It is also necessary to consider the safety impacts for all road users, modes, and situations, while adopting a holistic and integrated approach. Involvement of safety experts, practitioners, and stakeholders in the planning, design, and review of the safety analysis is crucial. Finally, you should monitor and evaluate the safety impacts and the effectiveness of the mitigation measures after the development is completed.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?