Highway projects are thought to be influenced by many different types of delays. Data collected from twenty-eight Texas highway projects over a two year period found that utilities conflicts, rain and shortage of materials are the only three significant disruptions. Research also found that most of the disruptions caused production to stop between one to five days while few had stoppages of more than ten days. This paper also found that productivity recovery from different types of delays was different and that learning effects had huge impact on the rate of recovery. The research identified several useful factors that could be used to develop statistical models to estimate delays on reinforced concrete pipes. First, rain related productivity delays could be estimated by differentiating clay content in soil. Second, utilities conflicts could be estimated by differentiating the types of utilities that were involved. Finally, the actions that were taken by the contractors could be used as factors to measure productivity recovery. The overall project delays could be estimated using these factors. These factors were also found to be extremely useful to resolute disputes on time claims due to disruptions.