OTREC-RR-11-03 part 1

This study aims to improve understanding of how equipment replacement decisions are supported with data collection and quantitative models at state DOTs, and to determine if models found in research literature offer better support when applied to real fleet usage and cost data. It also addresses the use of “green” criteria in replacement decisions, and the development of new replacement models. Responses from DOTs show little consistency in the criteria used in replacement decisions, as well as no use of “green” criteria. Most DOTs use information systems of cost and usage data as part of the replacement process. To see if a particular model performs better than those used in practice, a simulation was conducted to evaluated the effectiveness of models for prioritizing equipment replacement. Models from research literature were compared to a replacement model like those used by DOTs. Results show that models used in practice provide similar results to the best model from the research literature.