EVALUATION OF ALTERNATIVE NETWORK PRESERVATION STRATEGIES

A study was conducted to evaluate the effects of underfunding on the total long-term cost of preserving networks. Many state highway agencies are experiencing both declining revenues and declining trunkline conditions. This decline raises the following question: Which alternative has the lowest total cost of preservation--allowing the network to decline from its current condition and later restoring it or maintaining its current condition? The pavement management system developed for the Michigan Department of Transportation is a network management system that includes the ability to evaluate the effects any given funding scheme has on the long-term (40-year) total cost of network preservation. Five funding schemes were analyzed for the preservation of two networks consisting of more than 11,000 lane-mi of pavement. A manual version of Michigan's network management system was used because it provides a simple means of illustrating how a network management system is used to control the long-term relationship between funding schemes and network condition. Program costs were estimated on the basis of 3 years of historical project cost data. Five alternative funding schemes were evaluated, ranging from maintaining current condition to doing nothing for the first 10 years and then restoring the current condition. The study showed that the total agency cost over a 40-year analysis period can be highest when networks are maintained in current condition and lowest when they are allowed to deteriorate for 10 years before restoring and then maintaining current condition.