Highway Routine Maintenance Cost Estimation for Nevada
Creators: name: Hagood, Monika 
Publisher: name: University of Nevada, Las Vegas
Year: 2014

description: State highway agencies are obligated to maintain existing roads for the highway systems to work efficiently and with greater longevity. Every year NDOT is responsible for approximately 13,150 lane miles of existing infrastructure. With that in mind, resources need to be provided to maintain the highway system. 
The purpose of this research was to estimate annual routine maintenance cost for several typical treatment methods of highways. Five prioritization categories of highways used by NDOT were considered. Linear regression models were developed that present the relationship between costs including total maintenance cost and five maintenance cost components: labor, equipment, materials, manpower and stockpile, and the influencing factors: traffic load, road geometry, pavement structure, and climate. It was expected that the cost model depends on various roadway factors including elevation, number of lanes, age of the pavement, last year of pavement construction work, average daily traffic (ADT), number of trucks, single axial load (ESAL), district work done, and weather conditions. 
This research undertook the following steps: data review, data correlation check, and ordinary least square regression analysis. Data used for the analysis was extracted from NDOT pavement management system. Five NDOT prioritization categories were used for data processing and the analysis. The regression models incorporated the same parameters used in the NDOT pavement management system; therefore they can be simply combined with the existing database. 
The analysis conducted in this study indicates that road age is a noteworthy factor for a number of life cycle segments and several maintenance cost activities. The life cycle segments varied with each prioritization category including routine maintenance activities and their schedule. For segments where the roadway age does not appear to be significant, the routine maintenance cost estimate stays constant. Routine maintenance activities may be scheduled at the times that are close to the time when a preventive maintenance or reconstruction is scheduled. This practice is reflected in the cost model that the annual maintenance cost may decline with time and suddenly increase at the end of their life cycle stages. 
Lastly, recommendations have been made to provide fundamentals for future study needs. Several research needs in the cost estimation model are apparent from this assessment. These include additional information regarding cost model development using various statistical tools, periodical data update, use of a larger sample size, and different approaches for constructing prioritization categories life cycle. Also, historical data should be updated constantly due to changes in the material and construction technology. Further, the construction technology might require more or less steps with certain treatments like chip seal or flush seal. Thus, it is recommended to update the data as major construction or material technology is implemented in the routine maintenance work.