Criteria for Justification and Design of Auxiliary Lanes

Maximizing the potential capacity of existing roadways is becoming a priority due to growing congestion and limited resources for adding more capacity to the highway system. Including turn lanes in the design of a highway improvement project, or requiring turn lanes to be added as a result of new development, is a complex decision requiring the Cabinet to evaluate the anticipated demands for right or left turns to abutting land development and the anticipated benefits in delay and crash reduction against the cost and other impacts of the installation. The common method of analyzing and designing intersections on the basis of past experience, accident records, complaints from the traveling public, and engineering judgment has led to inconsistencies. Even where technical analysis is attempted, the most commonly used analysis tool (the 1967 Harmelink Methodology) is of questionable value due to the facts that the underlying assumptions are no longer valid for today's driving conditions and queue storage lengths frequently need to be longer than those indicated by the limits ofthe Harmelink curves.