Traffic Forecasting with 2016 HCM Methods Cody Stone, P.E. June 21, 2018

Safety Moment Computer Safety Traffic Forecasting with 2016 HCM Safety Moment Computer Safety Devote at least five minutes of every hour to a non-computer related task Stand up while on the phone Blink your eyes multiple times during computer breaks to avoid eyestrain

Agenda What is Traffic Forecasting? Traffic Forecasting with 2016 HCM Agenda What is Traffic Forecasting? Traffic Forecasting Application to 2016 HCM 2016 HCM Components of Traffic Forecasting Traffic Forecasting Standard Operating Procedure Tools for Traffic Forecasting Questions? How many people use traffic forecasts on their projects or for their work? Now, how many of you all develop those traffic forecasts?

What is Traffic Forecasting? Traffic Forecasting with 2016 HCM What is Traffic Forecasting? Traffic forecasting is the attempt to estimate the number of vehicles that will use a roadway in the future. Why is it so important? Ultimately, so we do not underdesign (pic on left) or overdesign (pic on right) our roadways. Also, it is important to consider the vehicle type, i.e. number of trucks.

Traffic Forecasting Application to 2016 Highway Capacity Manual (HCM) Traffic Forecasting with 2016 HCM Traffic Forecasting Application to 2016 Highway Capacity Manual (HCM) Current or Near-Term Conditions Operational Analysis Mid- to Long-Term Implementations Design Analysis Long-Range Analyses Planning and Preliminary Engineering Analysis Traffic Forecast Application Level Where is traffic forecasting applicable in the engineering project development? It is mainly focused on analysis of mid and long term improvements. Short term improvements can often be analyzed using existing counts and field observations, while traffic forecasting is essential to making accurate mid and long term analyses.

2016 HCM Components of Traffic Forecasting Traffic Forecasting with 2016 HCM 2016 HCM Components of Traffic Forecasting Historical Count Data Historical counts as far back as you are forecasting forward Identify growth trends Travel Demand Model Changes in demographics and land use There are several HCM components that we consider when developing traffic forecasts. The first is looking at historical count data. It is important we understand growth in the past and what lead to the current traffic demand. We can identify trends, like if we feel the growth is trending downward due to land use saturation.

2016 HCM Components of Traffic Forecasting Traffic Forecasting with 2016 HCM 2016 HCM Components of Traffic Forecasting Planned Development and Land Use Another important item to consider is planned development and updated land use. At a specific project location, it may be important to incorporate the trip generation of a site plan to capture the local demand. We can also use the area’s travel demand model to anticipate area growth for major corridor projects. Different purposes to forecast traffic; TIA, corridor analysis, toll analysis, etc.

2016 HCM Components of Traffic Forecasting Traffic Forecasting with 2016 HCM 2016 HCM Components of Traffic Forecasting Variations in Demand – Monthly, Daily, and Hourly Traffic forecasts also consider variation in demand based on hour, day, and month. Seasonal adjustments can sometimes be applied to counts. At certain locations, weekend and event traffic counts and forecasts should be considered. For operational analysis, engineers and planners should carefully consider when a mid-day peak period should be analyzed, in addition to the length of the traffic analysis. This way traffic forecasts can be created that fit the operational analysis scope and overall goals.

2016 HCM Components of Traffic Forecasting Traffic Forecasting with 2016 HCM 2016 HCM Components of Traffic Forecasting Uninterrupted Flow vs. Interrupted Flow Freeway Urban Streets “Uninterrupted” is access controlled, mainly freeway facilities. Urban streets have intersections and driveways that interact along a corridor.

2016 HCM Components of Traffic Forecasting Traffic Forecasting with 2016 HCM 2016 HCM Components of Traffic Forecasting Demand Volumes NOT Observed Volumes “Observed volumes may reflect capacity constraints rather than true demand. Demand is usually the desired input to HCM analyses, although it is not always easy to determine.” –2016 HCM, page 4-2 MAJOR component to traffic forecasting. As most of you are aware, observed counts can be vastly different than demand, especially in a very congested network. Sometimes we reference “induced” demand, when it could have actually been that the forecast used the counts as a baseline. The graph shows how demand can exceed capacity at peak periods, this would result in a flat-lining of traffic counts. Many roads are at capacity and demand diverts to other modes or facilities.

2016 HCM Components of Traffic Forecasting Traffic Forecasting with 2016 HCM 2016 HCM Components of Traffic Forecasting What will the traffic forecasts be used for? Pavement Design Air and Noise Analysis Operational Analysis Toll Analysis This will help determine if you need 24-hour traffic volumes, percent trucks, K factor, etc. The operational analysis portion is key because sometimes a design-hourly volume is not enough to fully analyze a corridor. It is important to develop the traffic forecast methodology that would consider the peak periods of analysis.

Traffic Forecasting Standard Operating Procedure Traffic Forecasting with 2016 HCM Traffic Forecasting Standard Operating Procedure Lessons Learned from Previous Projects Training Tools & Innovation Sometimes easy to say, “well its just growing traffic numbers”…well, it is a bit more involved and can become very complicated on major corridors or with a high level of congestion. I’ll next go over some project development tools that can be used on traffic forecasts. Implement Corridor Analysis SOP Schedule Multi-disciplinary/practice Collaboration Multiple types of corridors

Traffic Forecasting Standard Operating Procedure Traffic Forecasting with 2016 HCM Traffic Forecasting Standard Operating Procedure TPP has a well defined process and we are familiar with its details, the data TPP uses, and common mistakes made by those new to the process.

Traffic Forecasting Standard Operating Procedure Traffic Forecasting with 2016 HCM Traffic Forecasting Standard Operating Procedure Important components to project delivery are following flow of tasks and having set QC points for review.

Tools for Traffic Forecasting Traffic Forecasting with 2016 HCM Tools for Traffic Forecasting SharePoint Excel List of Tools GIS Sharepoint with Excel Diversion and Adjustments Line Diagram Layout and Set-up GIS Diversions/Adjustments Diversions Lets go over some of the cool tools. Simple things that avoid a headache. CAD Import Line Diagrams

GIS Standard GIS TxDOT Statewide Planning Map Traffic Forecasting with 2016 HCM GIS Standard GIS TxDOT Statewide Planning Map Show type of TxDOT counts used from Database Management Systems Project Location or Limits Line Count Locations Easy to read maps showing where the data is from and what we are using.

MS Teams collaboration suite Traffic Forecasting with 2016 HCM SharePoint Excel MS Teams collaboration suite Integrates with SharePoint, OneNote, Skype for Business Access to Excel Online Allows multiple people to access and edit file simultaneously Avoid restriction of 1 person working at a time Tight project deadline Numerous tasks that could be performed simultaneously

Diversions/Adjustments Traffic Forecasting with 2016 HCM Diversions/Adjustments “The accuracy of the performance evaluation may be adversely affected if volumes are not balanced.” -2016 HCM, Page 18-25 Can be the biggest headache in traffic forecasts – difficult to develop consistent set of volumes. New roads and manual diversions can be complicated and difficult. Sometimes people prefer to do this the old fashion way.

Diversions/Adjustments Traffic Forecasting with 2016 HCM Diversions/Adjustments Excel Method Flexible Minimizes calculation errors Enhances efficiency by linking to other sheets But setting up in Excel allows any updates if assumptions or preferences change.

GIS Line Diagrams Straight Line Analysis Complete Corridor Analysis Traffic Forecasting with 2016 HCM GIS Line Diagrams Straight Line Analysis Complete Corridor Analysis

CAD Import Traffic Forecasting with 2016 HCM Setting up an import so that you don’t have someone entering numbers in for a week straight.

Questions? Cody Stone, P.E. cstone@emailatg.com Thank You!