Using the existing conditions analysis as a base, high level scenario planning and modeling were conducted to determine the future 2045 conditions of US 27 without improvements to the study corridor. This is known as a No-Build scenario.

The subarea validation adjustments made to the Base Year 2015 were carried over to the 2045 Cost Feasible model. The National Cooperative Highway Research Board (NCHRP) Report 765 recommends the Factoring Procedure-Difference Method and Ratio Method approach, which was further utilized to correct the errors associated with the validated regional model projected volumes. The averaging from the two methods reduces the extremes that may be reached by one of the individual methods of difference method or ratio method. More details on the traffic methodology are included in Appendix A. As part of this Study, two alternatives were evaluated, the No-Build alternative and General-Purpose widening (or Build alternative), The results of this analysis are provided in following section. The results of the Build alternative will be discussed in Section 4.

The No-Build alternative from the 2045 cost-feasible model was used to predict future traffic volumes and patterns. This alternative included improvements based on the 2045 Cost Feasible Plan consisting of improvements north of the study corridor and completion of the Central Polk Parkway East and West and the Poinciana Parkway Extension, as shown in Figure 16. These projects have the potential to enhance the mobility of the transportation network by providing direct access to I-4 which could contribute to additional demand on US 27. The potential developments (not incorporated in current version of D1RPM), received from the Highlands County and the District 1 office (https://arcg.is/1r5GvC) were also included.

The No-Build model evaluation indicates that US 27 near the Highlands/Polk County Line, Sebring and south of SR 66 and north of the study corridor is predicted to be at or near capacity by 2045, resulting LOS outside the acceptable range (LOS D), according to FDOT standards, as shown in Table 12. Segments are divided based on the resulting LOS. Segments of US 27 operate with volume-to-capacity (V/C) ratio over 1.0 in 2045 indicating a congested transportation system. For US 27, acceptable Level of Service Standard is "D". The AADTs ranged from 17,500 to 63,000 in the No-Build along US 27 within Highlands County. The highest AADTs were observed around Sebring, south of US 98, within Avon Park and at Highlands/Polk County line. The peak hour LOS analysis shows that most of the sections along US 27 withing Sebring, at the Highlands/Polk County Line and south of SR 66 shows LOS E, and is not within acceptable LOS standards. Providing additional capacity is considered as an initial alternative to address this increase in demand and growth of the region.

Figure 17 shows the peak hour and peak direction LOS along US 27. Figure 18 depicts the ranges of AADTs and Figure 19 shows the daily truck volume along the US 27 study corridor. 2045 Daily Truck Volume is calculated by multiplying 2045 AADT from D1RPM and 2023 T- factors from FTO.

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