B&N performed capacity and safety analyses throughout the state of Kentucky, including a relocation safety analysis, safety analysis training and review, and traffic forecast development.
Relocation Safety Analysis
As part of this task, the safety benefits of relocating a five-mile stretch of the existing KY-185 corridor to fix numerous horizontal and vertical deficiencies were evaluated. The Interactive Highway Safety Design Model (IHSDM) was used to perform the analysis of the proposed five-mile realignment as well as two potential spot improvements of approximately one mile each.
There were 86 reported crashes between January 1, 2012, and December 31, 2016, along the five-mile existing KY-185 alignment. Nearly 80% of the crashes involved a single vehicle, with most of those crashes occurring when the driver lost control of the vehicle, left the roadway and either collided with an embankment, guardrail or another fixed object outside the roadway or overturned. After analyzing the crash patterns, the B&N team determined that the existing horizontal and vertical alignments were contributing factors to these crashes. Based on the IHSDM analysis, it is estimated that there will be 20 more crashes in the KY-185 corridor between 2018 and 2037 than other similar sites.
The realignment of the entire corridor has the potential to mitigate over 221 crashes, or 11 crashes per year, at an estimated construction cost of over $23 million. By focusing on the two areas that need realignment the most based on the existing crash patterns, over 142 crashes, or seven crashes per year, can be mitigated for a total construction cost of just over $13 million. This analysis allowed the Kentucky Transportation Cabinet (KYTC) to spend less on realigning KY-185 while significantly improving safety.
Safety Analysis Training and Review
B&N provided training on the use of the IHSDM for analyzing two existing interchanges as well as a proposed interchange along I-71 at Milepost (MP) 20.6. In addition, the training included an introduction to safety terminology and methodologies. After the safety analysis for the interchanges across a multitude of scenarios was completed by another firm, B&N provided a quality review of the safety analysis for inclusion in the final plans.
Traffic Forecast Development
B&N developed traffic forecasts for two projects along I-71 in Louisville. Socioeconomic data in the Kentuckiana Regional Planning & Development Agency (KIPDA) and KYTC Statewide Model were reviewed and adjusted to account for specific developments occurring in the corridor. Growth rates were developed based on the model runs. Existing and 2045 average daily traffic, AM and PM forecasts and a technical memo was prepared.