2018 Issue

57 Figure 2 shows the three segments of the construction project along 1300 East: Creek Road to 8600 South, 8600 South to 9400 South, and 9400 South to 11000 South. Analyzing the Data In 2015, Sandy City requested a crash analysis to determine if the safety improvements constructed within the project limits had reduced the total number of crashes and the severity of crashes. Project Engineering Consultants Ltd. (PEC) analyzed the pre-construction crash data from 2006 to 2009 and the post construction crash data from 2010 to 2014, to address the highest number of severe crashes and the locations with the most crashes. Severe crashes and clusters of collisions were used to estab- lish predominant manners of collision and areas of concern. For the purpose of this study, severe crashes were identified as those involving a fatality or a person being taken to a hospital by ambulance. Identifying the severe crashes estab- lishes which manners of collision were critical at a given location. Once the manners of collision related to the severe crashes were identified, similar crashes with lesser severity levels were examined to determine if a pattern of crashes ex- isted in that area. If a high number of less severe crashes were reported in an area, those crashes were analyzed to deter- mine if a pattern of multiple crashes of the same manner of collision occurred. If five or more crashes of the same manner of collision occurred, regardless of the lack of a severe crashes, that areas was identified as a crash cluster and evaluat- ed as part of this study. The 1300 East corridor crash data was divided into three segments related to one of the three construction phases for the purposes of this study. The segments were further divided into smaller sec- tions of intersections or road segments. Each section was analyzed individually to determine if certain sections had more severe crashes or more crash clusters than others. From the pre-construction data, eight areas of concern (representing intersec- tions and road segments) were identi- fied. Similarly, six areas of concern were identified using the post construction data; four of these areas were the same as those identified from the pre-con- struction data (See Figure 3). Figure 3 shows the average number of crashes per year for the areas of concern. Pre-Construction Areas of Concern The eight areas of concern identified in the pre-construction data were established based on the severity of crashes and clusters of collisions in the area. Four of the sections identified in the pre-construction data as areas of concern were no longer areas of con- cern after the construction due to the reduction in the number and severity of crashes at these locations. Even though crashes were reduced at most loca- tions, four of the intersections remained areas of concern following construction: Forbush Lane, 8600 South, 9400 South, and Sego Lily Drive (See Figure 4). The following is a summary of the analysis of these eight areas of concern. Figure 4 shows the areas of concern post construction and pre construction. 7625 South Intersection At this signalized intersection, 23 crashes were recorded in the three years prior to construction. Five of the crashes were angle crashes; 16 were front-to-rear. Safety improvements at this intersection included new lighting, new striping, new median curbs, and ADA compliant pedestrian ramps. After the intersection improvements were made at this location, six crash- es were recorded during the follow- ing three-year period—a 74 percent decrease in annual crashes. For this reason, this intersection is no longer an area of concern.