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The Tennessee Department of Transportation (TDOT) is adopting the Highway Safety Manual (HSM) as a resource to assess the safety performance on Tennessee (TN) roadways. The HSM (2010) provides Safety Performance Functions (SPFs) to predict crash frequency on several types of roadway facilities, eg, segments and intersections. HSM recommends that transportation agencies develop either their own jurisdiction-specific SPFs or calibrate the default HSM SPFs using local data. The rationale behind this is that the HSM SPFs were developed using data from a few states in the US, which may not be representative of other states due to potential variability in conditions. To assist with implementing HSM procedures, the University of Tennessee has worked closely with TDOT to develop TN-specific SPFs for various types of rural and urban roadway segments in Phases I and II of the project. This phase (III …