When is a Traffic Impact Study needed?

A traffic study is typically required when a proposed development or land use change is expected to generate additional trips on the surrounding transportation network. Agencies request a traffic study to evaluate how a development may affect traffic operations, roadway safety, and infrastructure — and to determine whether improvements are needed to mitigate potential impacts.

As discussed in previous posts, the level of analysis and documentation depends on factors such as the size of the development, the number of trips expected to be generated, and the specific requirements of the local municipality. Most traffic studies fall into one of two categories: a Trip Generation Memorandum or a Traffic Impact Study (TIS) / Traffic Impact Analysis (TIA).

When a Trip Generation Memorandum or TIS/TIA Is Typically Required

1. New Developments or Land Use Changes

• Construction of new residential, commercial, industrial, or mixed-use projects

• Redevelopment projects that increase intensity or change the land use type (e.g., converting retail to a drive-thru restaurant)

2. Trip Generation Thresholds

A TIS/TIA is often required when a development is projected to generate a certain number of new daily or peak-hour trips. Example thresholds:

• Miami-Dade County: More than 100 peak-hour trips

• Monroe County: More than 249 daily trips

3. Access Management or Driveway Permits

A traffic study may be required when a development proposes:

• A new driveway connection to a public roadway

• Modifications to an existing access point

4. Zoning Changes or Land Use Amendments

• Traffic studies are often needed when requesting:

  • A rezoning

  • A comprehensive plan amendment

  • A special use permit

5. Agency or Local Government Requirements

Need a Traffic Study for Your Development?

Whether you're working on a new site plan or preparing for a development application, our team can help you navigate the traffic study process from start to finish. We specialize in preparing traffic studies that meet local requirements while supporting timely approvals. Contact us today to request a proposal or learn more about our services.