Project traffic is the amount of multimodal traffic with respective characteristics that is expected in an existing or proposed transportation facility in the future. Project traffic estimates are required for planning, Project Development and Environment (PD&E) studies, design, construction, and pavement design including Resurfacing, Restoration, and Rehabilitation (RRR) projects, and traffic engineering studies. Project Traffic Forecasting is used to evaluate the performance, design, and impact of a transportation facility and its effect on the surrounding network and the environment. A project traffic report is routinely prepared as part of most PD&E Studies to document the existing conditions and the development of future project traffic data. The 2024 FDOT Design Manual (Chapter 913) requires traffic data consistent with the data used for pavement design to be included in each typical section. Pavement design considers the total amount of truck traffic accumulated during the expected service life of a roadway segment.

Project Traffic Forecasting is a complex and resource-intensive process that requires a large amount of data, detailed analysis, and specialized expertise. It often involves making reasonable assumptions and judgments based on the available information and methods. Project Traffic Forecasting is subject to uncertainty and variability, as there are many factors that can affect the future traffic demand and behavior, such as economic conditions, population growth, land use changes, travel preferences, technology innovations, and policy interventions. Therefore, Project Traffic Forecasting should be done with caution and transparency.

Project Traffic Forecasting plays an integral role in the project development process. It helps decisionmakers evaluate their options and select the best alternatives to meet project goals and objectives. It is critical that the forecasting is done in a logical, consistent, and transparent manner throughout the entire project development process. The Project Traffic Forecasting Handbook offers guidelines and techniques to facilitate the implementation of a consistent traffic forecasting approach in the state. It describes the three (3) forecasting processes, which include Corridor, Project, and the 18- KIP Equivalent Single Axle Load (ESAL), in detail.

Corridor projects usually require the development of traffic projections that are used to make decisions with important capacity and capital investment implications. Corridor Traffic Forecasting is required before establishing a new alignment or widening of an existing facility.

Project traffic projections are commonly used to develop lane configuration requirements for intersection designs, and to evaluate the operational efficiency of proposed improvements. Project Traffic Forecasting is also required for reconstruction, resurfacing, lane addition, bridge replacement, new roadway projects, and major intersection improvements. This process differs from Corridor Traffic Forecasting in that it is site-specific and covers a limited geographic area.

The 18-KIP ESAL Forecasting Process is required for the pavement design for new construction, reconstruction, and Resurfacing, Restoration and Rehabilitation (RRR) projects that require a structural loading forecast.