DEVELOPMENT OF GUIDELINES FOR LOCATION OF PASSING LANES ON TWO-LANE ROADS

This paper presents a discussion of warrants for provision of passing lanes on rural two-lane highways, and developments of passing lanes warrants for the state of Kansas. Warrants for passing lanes are considered to involve two sub tasks; namely, 1) the process of selecting highway sections which need passing lanes(s) in order to improve the quality of traffic operation; and 2) the process of selecting the physical location along the highway section to place the passing lane. Available guidelines used by different jurisdictions as reported in the literature combine the two processes directly or indirectly into one process. Combining the two processes may lead to a process which is inefficient; and may lead to providing passing lanes where they are not needed most within the state network. It is recommended that provision of passing lanes be provided at two stages. The highest stage or network level should select highway sections that are in need of improvement because of low, prevailing level-of-service. At the second level, or project level, the selection sections at the network level should be ranked in order of priority based on some prioritizing scheme such as benefit-cost analysis. The paper compares available guidelines from the literature and gives an example of using the two-step network-project framework. The example illustrates the proposed framework for warrants of passing lanes.