The updated 2015 SE data were used as input to perform the regional validation. ZDATA files, namely ZONEDATA_15A.DBF was updated accordingly for the model inputs. As previously noted, centroid connectors of several traffic analyses zones (TAZs) were reconfigured along the US 27 corridor consistent with the base condition to better represent land use and development along the corridor and to improve the model trip assignment for the US 27 study area.

The 2015 base year model was updated with the 2015 daily traffic counts from FTO, and 2015 land use, as detailed in the previous sections. The subarea model was then validated based on year 2015 conditions. Initial step before validation was to evaluate the Root Mean Square Error (RMSE) by volume group and volume/count (V/C) by facility type for the daily volumes. The acceptable and preferable thresholds were taken from FSUTMS-Cube framework Phase II, Model Calibration and Validation Standards and D1RPM.

Tables 6-2 and Table 6-3 summarize the results of the subarea model RMSE and V/C statistics for daily volumes before validation. For the base subarea model overall V/C statistics are within the acceptable range for the daily volumes for most of the facility types. Also, the subarea model RMSEs are within the acceptable range for the daily volumes for all volume groups. However, the daily volume along US 27 were lower by -31% around the Sebring area. Even though the subarea model RMSE statistics does not show the need for further refinement at the subarea level, the efforts were focused to areas surrounding the US 27 corridor to reduce the disparity between daily counts from FTO and model volumes and refinement of TAZs.