Future year estimates of peak hour intersection turning movements are required for intersectiondesign, traffic operations analyses, and site impact evaluations. In most urban areas, traditionalFSUTMS-based travel demand forecasting models can be used to develop intersection turningmovement volumes with proper scripting and processing of model volumes. Model turningvolumes should be used in cases where new alignments are being developed. Another approach isto use peak period model turns from a Time-of-day travel demand models as a reference source forturning movement splits, particularly for now movements where existing traffic count data is notavailable. Manual methods have also been used in both urban and rural areas where models are notavailable or when model results are not considered accurate. Because of the difficulties involved ingenerating peak hour volumes directly from an urban area model for every possible intersectionwithin a given study area, various methods and procedures have been developed to estimate peakhour turning movement volumes from daily traffic volumes. Most of these methods rely on existingintersection turning movement count data and professional judgment.

Turning movement forecasts should reflect the logical effects of future year land use andtransportation network improvements on the traffic pattern at a given location. In general, ifthe pattern of land use and transportation system characteristics is expected to change, turningmovement patterns are also likely to change over time. Existing turning movements and modelsimulation results (when available) provide useful starting points for the turning movementforecasting process. The need for turning movement forecast refinements should be determinedby careful review of the chosen starting point. The forecaster must use K, D, and current turningpercentages, if available, for each approach for each leg of the intersection to calculate turningvolumes during the design hour.