STUDY OF THE EFFECT OF WEATHER ON ROAD CONSTRUCTION: A SIMULATION MODEL1

Daily engineering records from two road construction projects near Jefferson City, Mo., for the years 1965-68 were combined with soil moisture and precipitation measurements from nearby meteorological stations to develop a model capable of producing an experimental series describing conditions suitable for road building activities. This model was then applied to a long-term series of daily precipitation records for Jefferson City (1918-65) to calculate road construction conditions over this period. Monthly and seasonal statistics describing the feasibility of various levels of road building activity are presented for the 48-yr period. These statistics include second-order Markov chain probability estimates of working and nonworking days. Aside from the inferences which can be directly drawn from the seasonal and monthly descriptive data, the statistics may have value in developing further simulation models for estimating the effects of various management strategies. Effects of weather conditions on particular components of the economy have been considered by a number of investigators. Studies assessing the association between weather and agricultural production (Maunder 1968), housing starts (Musgrave 1968), retail trade (Linden 1961), electrical power production (Johnson et al. 1969), natural gas consumption (McQuigg and Thompson 1966) , and agricultural land prices (Johnson and Haigh 1970) are among those of more recent vintage. The weather sensitivity of the construction industry in the United States has also been considered (Russo 1966, Theil 1966, US. Department of Commerce 1966), but little attention has been devoted to the road building sector. Expenditures for road construction are, however, an important part of the total expenditure on construction and of the budgets of Federal, State, and local governments from which they are financed. In this study, effects of climatic variables on the highway construction industry are estimated through their influence on working conditions during the main construction months. Data from two construction projects are combined with a soil moisture index to obtain conditions under which construction activities can proceed. This relationship is used to generate an experimental series of working conditions based on available weather data. The resulting series of simulated working conditions are then assessed regarding their potential as aids to planning and scheduling highway construction projects.