Optimized route to clear diverging diamond interchange using discrete optimization method

Abstract

Interchanges and intersections are the most complex part of a roadway network and are very challenging for snow plowing operators. The objective of the study is to test if the empirical best plowing route to clear a diverging diamond interchange (DDI) recommended by Clear Roads is also mathematically optimized. A discrete optimization method was employed to find the shortest route. In the study, the DDI is represented as a directed graph model. The task of clearing all lanes is treated as the well-known directed Chinese postman problem, which was then solved by an existing network optimization algorithm upon appropriate modification. The results showed that the best practice plowing route recommended by Clear Roads is one of the computed optimal routes with the efficiency index of 2/3. The approach proposed in the study can also be applied to other complex intersections and interchanges and help agencies achieve cost-effective snow control operations.