6.3.2.1 4 Using Historical and Projected Conditions to Evaluate Performance Targets

Using Historical and Projected Conditions to Evaluate Performance Targets / South Dakota DOT

To determine the effectiveness of road investments, the South Dakota DOT uses historical trends and projects conditions for each road category to show whether targeted conditions can be achieved with planned investment scenarios. The figure to the right illustrates the type of graph developed for the Interstate network. As shown, the graph presents both historical and projected conditions based on a Surface Condition Index (SCI) that ranges from 0 to 5, with 5 representing a distress free pavement. Overlaid on the graph is the acceptable condition range, which in this case spans an SCI between 3.8 and 4.2. The graph shows that Interstate conditions gradually improved over time. Although it projects average future conditions to drop, they are expected to continue to fall into the acceptable condition range. The results of the analysis provide the agency with confidence that the planned investments will achieve the desired condition levels over the analysis period. In addition, the projections are updated annually to provide a picture of changing financial trends and funding availability. This allows the DOT to react to any downturn in the projections.

Past and Future Pavement Conditions and Goals

Source: South Dakota DOT Transportation Asset Management Plan. 2019. https://dot.sd.gov/media/documents/SDDOT2019TAMPFHWASubmittalrevised8-28-2019.pdf