Life-Cycle Economic Comparison of Common Signpost Materials and Types

摘要

There is a wealth of information related to life-cycle costs of different sign sheeting materials and considerable information on common signposts, but there is little or no information about the life-cycle costs of different types of signposts. The primary objective of this research was to determine the best cost-effective policy, consistent with safety, for signpost materials and types used on state highways in Kansas. From the initial literature review, a matrix was constructed detailing the various materials used for signposts by each state. This was followed with a survey questionnaire to gather information on what posts other states were using for three major types of signs used in Kansas. From the data obtained from the state departments of transportation, test installations were carried out by three vendors. Life-cycle economic analysis was conducted, taking into consideration the labor, equipment, and time requirements for the initial installation and the replacement. Among the four systems compared for a single signpost, the Poz-Loc Socket System is the most cost-effective alternative in life-cycle costs, followed by the Break-Out Sign Support System, the 4″ x 4″ x 14′ wood post, and the Telespar anchor-driven unit. Among the three systems compared for a double signpost, the Poz-Loc Slipbase System is the most cost-effective alternative, followed by the Telespar Slipbase System, and the double 4″ x 6″ x 16′ wood post. The present worth analysis and sensitivity analysis, conducted according to varying the interest rate, did not have any significant effect in changing the cost-effective alternative.