Determining the Average Available Workdays for ALDOT Construction Projects

Abstract

Construction scheduling in the dynamic field of highway projects is complex and time-consuming, with project delays and cost overruns setting critical challenges. This study highlights the significance of accurately estimating construction contract duration considering variable and untamed factors like weather. Highway construction projects are susceptible to impacts from weather as it can directly affect the duration of projects by causing delays to construction activities. The primary objective of this research was to develop comprehensive, weather-based guidelines for determining monthly Average Available Workdays (AAWDs) over many years for highway construction projects across Alabama's five Alabama Department of Transportation (ALDOT) Regions. AAWDs exclude weekends, legal holidays, rainy days, and days with cold air temperatures. The study is based on the analysis of weather data from 88 climate stations with at least 10 years of valid data. The project selected and tested several rainfall and air temperature thresholds of adverse weather (non-workdays) to determine variations of the monthly AAWDs with these parameters. The methodology utilized rainfall thresholds and air temperature to establish appropriate AAWDs for different Regions, considering variations in weather conditions. The results demonstrated variations in AAWDs across different months and Regions, with important implications for project planning. The study divided the state into climate zones, providing insights into differences in AAWDs. The monthly AAWDs for rainfall >0.2 in. and daily mean air temperature < 40o F as adverse weather thresholds were then determined for five ALDOT Regions. Annual AAWDs were determined to be 185, 193, and 200 days for three climate zones: ALDOT North Region, Central Regions (ALDOT East Central Region and West Central Region), and South Regions (ALDOT Southeast Region and Southwest Region) in Alabama, but monthly available workdays vary year by year and should be considered for project planning. The developed tool was verified by validating the results obtained to the data records from completed projects and the findings indicate that project durations may be considerably longer than required workdays due to various non-weather-related factors, prompting the need for more comprehensive project management strategies. This study provides practical tools, based on climate data and guidelines, to determine and update AAWDs efficiently. These resources empower ALDOT to enhance project planning and decision-making, ensuring accurate AAWDs calculations and facilitating effective management of highway construction projects across diverse weather conditions and regions.