Simulation-Based Analysis of Sign Blanket Replacement Strategies

Transportation agencies are responsible for maintaining traffic signs, a critical part of any transportation network, in a satisfactory condition. This is achieved by the implementation of sign maintenance and replacement strategies. This paper presents the results of a sign replacement simulation model based on the Blanket Replacement method. Although the case study described here was based on North Carolina (NC) sign data, its results provide insights for all transportation agencies about effective practices that result in cost-efficient sign replacement strategies. The authors found that daytime inspections reduce the number of unsatisfactory signs while having little effect on cost. Grace periods were found to be efficient in reducing costs. Longer replacement cycles (e.g., 20 years) that consider daytime inspections and a grace period resulted in more cost-efficient strategies than those with shorter replacement cycles (e.g., 10 years).