The impacts of design errors and omissions change orders on highway projects

Design errors and omissions are among the most common change orders in transportation projects. Other than the direct impact of these change orders on project schedule and budget, design errors and omission can have secondary impacts on dependent project tasks which increases the total cost and delays caused by the change order. Study of the change orders in Texas Department of Transportation projects over eleven years show that 31% of the total change orders (45 million dollar per year on average) are related to design errors and omissions. In this study, design errors and omissions change orders have been analyzed based on the main cause of the change order and the project type. Six metrics (frequency, average cost/time impacts per contract and average cost/time impact as percent of the project bid amount/duration) have been used to compare the monetary and temporal impact of change orders. The most influential reasons for design errors and omissions change orders and the most vulnerable project types have been identified along with some suggestions to prevent and mitigate the impact of this type of change orders.