Abstract:To determine the factors that influence pavement maintenance costs of California state highways and evaluate the impact of heavy-truck traffic on maintenance cost is the purpose of this paper. More than 1,100 one-mile sections of state highways were randomly sampled, and data from various sources were integrated to form a data base containing information on traffic, weather, geometric conditions, and pavement maintenance costs for the sample sections. Following an extensive explorative analysis of the data, a model of pavement maintenance cost was formulated. The most significant finding is that heavy-truck (five or more axles) traffic has a much larger impact on pavement maintenance cost than does light-truck traffic or passenger-car traffic. The estimation results indicate that, on a typical roadway, the average annual maintenance cost per heavy truck per day amounts to $7.60 per mile per year, while the corresponding cost per passenger car is approximately $0.08. The study further shows that one additional heavy truck per day will cost an additional $3.73 per mile per year of roadway for pavement maintenance. An increase of 50 heavy trucks will cost $183.10 per year per mile. The corresponding cost increases due to passenger-car traffic are $0.04 and $2.18 per year per mile, respectively. This study thus establishes that one heavy truck is equivalent to about 90 light trucks or passenger cars in terms of its impact on pavement maintenance cost.