As stated in Section 1.2, the purpose of the PTFH is to describe policies and procedures accepted by the FDOT and offer guidelines on principles and techniques for preparing project traffic required by various stages of the project development process. The objective is to help standardize the traffic forecasting process that will result in consistent and defendable project traffic on all applicable transportation projects. As for who uses the handbook, the intended audience is transportation engineers and planners who develop project traffic for various highway projects for FDOT and its partner agencies in the state of Florida. This Handbook may be used by local governments and other agencies to review, accept, or approve project traffic developed for highway projects within their jurisdictions.

As outlined in Section 1.1, project traffic forecasting plays an integral role in the project development process. It helps decision-makers evaluate their options and select the best alternatives to meet project goals and objectives. Here are the key stages in the project development process where traffic forecasting is typically required:

1. Corridor: used to make decisions with important capacity and capital investment implications. The Corridor Traffic Forecasting is required before establishing a new alignment or widening of an existing facility.
2. Project: used to develop lane configuration requirements for intersection designs, and to evaluate the operational efficiency of proposed improvements. It is also required for reconstruction, resurfacing, lane addition, bridge replacement, new roadway projects, and major intersection improvements.
3. 18-KIP ESAL: required for the pavement design for new construction, reconstruction, and RRR projects that require a structural loading forecast.

In summary, project traffic forecasting is needed at various stages throughout the project development process to inform decision-making and design considerations.

The PTFH describes the three forecasting processes which include Corridor, Project, and the 18-KIP ESAL in detail. Chapter 4 provides guidance on the use of models to develop traffic projections for project, corridor, and RRR projects. Please refer to the following for a more detailed illustration of steps for traffic forecasting:

1. Corridor Traffic Forecasting Process: Figure 4-1
2. Project Traffic Forecasting Process: Figure 4-2
3. ESAL Forecasting Process: Figure 8-1

If an acceptable model is not available for a project, then refer to Section 5.4.

As stated in Section 1.2, this Handbook may be used by local governments and other agencies to review, accept, or approve project traffic developed for highway projects within their jurisdictions. The specific use of the PTFH for non-state road projects would depend on the policies and guidelines of the organization or jurisdiction overseeing the project. It's essential to consult with the relevant local or regional transportation authorities and agencies. They may have their own traffic forecasting guidelines or standards that need to be followed. The PTFH is typically associated with the FDOT and is designed to provide guidance and standards for traffic forecasting specifically within the state of Florida.

Please visit the following website to check the available trainings and webinars offered the Systems Implementation Office: https://www.fdot.gov/planning/systems/systems-management/trainings-webinars

Please contact the FDOT Systems Implementation Office and the contact information is provided on the following website: https://www.fdot.gov/planning/systems/Systems-Management.shtm

Yes, the spreadsheets can be downloaded from the following website: https://www.fdot.gov/planning/systems/systems-management/systems-management-documents Also, the download link is included in the PTFH chapters to introduce these tools.

In general, it's recommended to use the most recent and relevant traffic data available for project analysis. Project traffic data can become outdated over time, and determining when it is considered "too old" depends on several factors, including the purpose of the data, the land use change in the area, and the specific project or analysis in question. When using older data, it's important to acknowledge its limitations and consider the potential need for adjustments or validation to account for changes in traffic patterns over time. As stated in Part 1 Section 4.2.2 of the PD&E Manual, effective July 1, 2023, the planning product being adopted into the NEPA analysis was approved within the 5-year period ending on the date on which the information is adopted or incorporated by reference.

As outlined in Section 4.7, the traffic for interim phase can be obtained from model outputs in the developed interim phase land use and network scenarios. If the interim phase is defined as a year between the opening year and the design year without project changes, the interim phase traffic can be developed by interpolating between the opening year and design year traffic.

Project traffic forecasts for managed lanes require an additional level of effort compared with the traditional forecasting methods provided in this Handbook. Please refer to Chapter 9 for project traffic for tolled managed lanes. In addition, FDOT has developed a Managed Lanes Guidebook to provide guidance on the planning and implementation processes of managed lanes projects and associated technical, organizational, and outreach requirements. The intent of Chapter 9 is to supplement the FDOT Managed Lanes Guidebook and provide additional guidance on the development of project traffic during the project development process for Express Lanes. This chapter is not intended for use in traffic and revenue studies.

The WIM locations can be found on the Florida Traffic Online (FTO) website by selecting the layer of WIM Locations. Additional information is provided in the following link: https://www.fdot.gov/mcsaw/weighstationlisting.shtm

As stated in Section 4.2.1, the traffic forecasting for a new corridor or improving existing facilities follows the seven-step corridor traffic forecasting process shown in Figure 4-1. Utilizing travel demand models to simulate traffic patterns on the new corridor involves developing a model scenario that represents the anticipated traffic flow, considering the roadway's design and surrounding land uses. Please refer to Section 4.7.2 for reasonableness checks on future year forecasts and Section 5.4 for DDHV development on a new facility.

Historical traffic counts are typically used to establish traffic growth trends. There are no specific factors for adjusting historical traffic counts if the count data obtained from the FTO website is already AADTs. Otherwise, please refer to Section 2.5.1 for converting ADT to AADT. Additional checks may be conducted to see if the count data is computed (field collected) or estimated due to various reasons that the data collection could not be performed for the specific year(s), or if the count data had experienced significant impacts such as the COVID-19 pandemic.

Axle correction factors (ACF) are applied in traffic data that records axle-based information. Please refer to Section 2.4.2 for the application of ACF.

As stated in Sections 2.4.1 and 2.4.2, Seasonal Factor Category is determined by using traffic data collected from permanent count location to develop monthly seasonal factor and weekly factor. ACF are determined by using the data from continuous and short-term classification counts following the guidelines as described in the FHWA Traffic Monitoring Guide. The seasonal and axle factors can be downloaded from the FTO website by selecting the Traffic Reports in terms of Peak Season Factor Category and Weekly Axle Factor Category. More details of using the reports are included in Sections 2.9.1 and 2.9.2.

Seasonal Factors (SF) are used to convert an average weekday 24-hour traffic count to AADT. Peak Season Conversion Factors (PSCF) are used to convert a 24-hour count, representing the average weekday daily traffic, to PSWADT. Please refer to Section 4.7.3 for more details.

Addressing outliers in traffic counts is essential when establishing a traffic growth trend to ensure that the trend accurately reflects the typical traffic patterns. Here are recommendations to address outliers: 1. Identify Outliers: start by identifying outliers in the traffic count data. Outliers are data points that significantly deviate from the overall trend or pattern. Common techniques for identifying outliers include visual inspection of data plots, statistical methods, and automated outlier detection algorithms. 2. Understand the Source of Outliers: investigate the reasons behind the outliers. Outliers can result from various factors, such as data collection errors, equipment malfunctions, extreme weather events, accidents, construction, or special events. Understanding the source of outliers is crucial for deciding how to address them. 3. Statistical Methods: consider applying statistical methods to handle outliers, such as replacing outliers with the nearest non-outlying values, removing a fixed percentage of the most extreme outliers from the dataset.

For project traffic forecasting purposes, the base year is the year when system data is collected to evaluate the existing conditions and establish the purpose and needs of a project. Please refer to Section 4.2.3 for more details. If a different existing or analysis forecasting year is proposed, please clearly document your rationale for selecting the existing and forecasting years. Ultimately, the choice of existing and forecasting years should align with the project's objectives and requirements. It should also consider the availability of reliable data and account for factors that may impact transportation conditions over the chosen timeframe. The FDOT Project Manager and other relevant stakeholders should be consulted to establish analysis years before the project begins.

Please refer to Section 4.3.5 for travel demand models available in Florida. Additional information can be found from the following FSUTMS Web Portal.

As mentioned in Section 4.2.3, in many cases, the model base year is different from the project base year. Likewise, the forecast year of the model could be different than the design year of the project. Standard data processing procedures, such as linear interpolation or extrapolation, should be used to ensure that the model provides traffic forecasts for both the opening and design year of the project.

Manually balancing the estimated intersection turning movements can be time and labor intensive and presents challenge with review and quality control, especially with large project areas. It is recommended that count data be adjusted and balanced between upstream and downstream locations using Excel spreadsheets or other tools that can help with review and quality control. There are several methods considered for balancing: split the difference between intersections, higher volume distributed to all movements, higher volume distributed to through movements, spreadsheet link volume forcing, and a combination of all or some of the other methods. In addition, Synchro can be used as a tool for intersection turning movements balancing, especially along arterial corridors where signal timing and other traffic analyses are being conducted. Synchro can display the traffic volume imbalance along a link, which can help expedite the balancing process. As specified in Section 5.8 Quality Assurance of 2021 FDOT Traffic Analysis Handbook, a 10% difference between upstream and downstream counts for location with no known traffic sources or sinks (such as driveways or parking garage) is considered acceptable. However, some districts have more stringent requirements, such as 7%. Please consult with the individual districts to establish the minimum acceptable threshold.

As stated in Section 2.5.2.2, a new approach to developing the Standard K Factors considers context classification, area type, and facility type of a roadway segment. It is recommended that the selected K Factor for a project fall within the K Factor Range. With the new K Factor Range, there could still be cases where the K Factor Range may not directly apply. In such cases, short-term traffic counts that include both weekdays and weekends should be collected. K Factors should be developed by analyzing the short-term traffic counts and relevant traffic information from FTO, if available. As stated in Section 2.5.3.2, If traffic counts for the project site are not available, obtain short-term traffic counts to determine hourly traffic volume distribution. This will allow the identification of the peak hour of the day and peak direction during the peak hour. If no counts are available, the intersecting roadways that are non-state maintained will use the same D-Factor as the project roadway on the state highway system. The D-Factors should be checked to see if they are within the allowable range.

There is no specific minimum growth rate prescribed universally for future traffic forecasting because the rate of traffic growth can vary significantly depending on the region, location, type of road, economic conditions, and other factors. In the case that the calculated traffic growth rate is unreasonably higher or lower than growth rates from other sources, a comprehensive traffic growth rate should be established using more data sources. It is recommended that the expected population or employment growth of the area and the overall average traffic growth rate for all roadways in the area be considered. When a trend analysis produces minimal or negative traffic growth rates, a minimum traffic growth rate of 0.5 percent annually is currently applied to traffic forecasting in some districts, but it is recommended to work with individual district offices to establish the appropriate minimum growth rate for the study at hand.

Currently there is no specific guidance to differentiate these forecasted volumes in this case. Additional documentation or reporting a volume as "between 10,000 and 10,500 vehicles per day” may help understand how the forecasts were derived.

Please refer to Section 7.8 regarding the two main tools used in Florida for developing turning movement volumes.

Please refer to Step 6 of Section 8.6 as the example shows a negative growth and considers other factors to calculate 18-KIP ESALs.

The newly released ESAL tool has updated the input for number of lanes from “one direction” to “by direction” (See Figure 8-13).