AHP-Based Decision-Making Process for Median Barrier Installation

The median barrier installation project for the 4-lane or wider national highways is in progress in order to prevent accidents. In order to maximize the effectiveness of median barriers, the priorities of median barrier installation should be decided reasonably and realistically by an adequate evaluation process. The monetary evaluation methods that have been usually used to give priorities to the alternatives have some limitations in reflecting various factors, especially considering qualitative variables that are related to decision-making problems. On the contrary, the AHP (Analytic Hierarchy Process) is a flexible model that deals with the qualitative variables and allows us to make decisions by personal judgment in a logical way. This study establishes a process for deciding priorities for median barrier installation using AHP (Analytic Hierarchy Process). We provide a systematic framework for the decision-making process on, the basis of conditions of road sections and the overall priorities of evaluation factors. This framework reflects multiple criteria (economic efficiency, safety, possibility of installation, and regional equity) synthetically, and it gives the greatest weight to safety (prevention of head-on crashes, rates of which are most strongly affected by median barriers).