Evaluation of US 119 Pine Mountain Safety Improvements - Federal Aid Research Task No. 121

The safety improvement project for a section of US 119 across Pine Mountain in Letcher County was initiated as an interim effort to address safety issues related to roadway geometrics, and specific problems related to truck traffic. The project involves sections of the road being improved over a 7.2-mile length at a cost of approximately $36 million. A preliminary evaluation study by a consultant had identified specific problem locations in the greatest need for improvement. As a result, a contract was awarded to begin spot-improvement reconstruction of roadway sections in the summer of 2002. There are other contracts to be awarded to complete the project; however, the projected completion date is October 31, 2003. The Transportation Center at the University of Kentucky has been requested to perform an evaluation of the safety improvement project on US 119 to determine whether the types of improvements undertaken have affected the overall safety of the roadway. Specific objectives will be as follows; 1) to determine the effects of a ban on truck traffic that was implemented in March 2001,2) to determine if the types of improvements undertaken as part of the project are applicable to other locations, and 3) to determine if the use of flexible design was successful by allowing the Transportation Cabinet to remove the truck restriction by permitting trucks with dimensions up to the WB-50 design to travel across the mountain and be able to track within their own lane. The proposed approach is to perform a three-phase evaluation over a period of approximately three years. Following is a brief description of the three phases. Phase 1: Detailed analysis of crash data representative of conditions on US 119 prior to beginning the. safety improvement projects. Maximum use will be made of the crash analysis performed by the engineering consulting firm of Bernardin-Lochmuller and Associates as part of their study completed in February 2001. The focus will be on the effects of the ban on truck traffic from this section of US 119 during the period between March 2001 and June 2002. A secondary analysis will be to perform an evaluation of types and patterns of crashes, followed by a subjective projection of the anticipated changes in crashes resulting from the improvements. Phase 2: Application of the Interactive Highway Safety Design Model (IHSDM) to produce an estimate of the changes in number and types of traffic crashes. This analysis will require detailed input of before and after geometric design parameters such as grade, curvature, lane widths, shoulder widths, etc. The IHSDM is used to build a safety baseline using existing conditions and estimate the changes representing the reconstructed geometrics. Phase 3: Traditional analysis of traffic crashes before and after completion of the spot safety improvement project. It is expected that the analysis will be made using data before the truck restriction, during the truck restriction, and after the project with the restriction extended or removed. This type of analysis will require that the evaluation period be extended for two years beyond completion of the project. A preliminary summary of crashes will be provided one year after project completion followed by a more detailed analysis extending over a two-year period after project completion.