TIME PREDICTION MODEL FOR HIGHWAY CONSTRUCTION

Abstract

This paper presents a time prediction model for asphaltic road construction. The model is developed by determining factors influencing the time duration of critical activities and lag times. The critical activities are classified into five groups: preparation, earthwork, subbase, base and incidental. The data of forty completed highway projects during 1992 to 1997 are collected from the Department of Highways in Thailand. Using a multiple regression method, the time prediction equations of all critical activities and lag times are developed. The total project duration can be estimated using a Critical Path Method (CPM) by summing the predicted times of activities which are on the critical path. The average errors from the prediction model and the traditional estimation method when compared with the actual construction time of the seven new completed projects are within ±13% and ±28%, respectively. The estimation time from the prediction model is also highly correlated with the actual project time. As a result, the model provides a reasonable estimate for the project duration of asphaltic road construction, especially when using the result in the planning stage.