University of California Transportation Center

Very little is known about construction equipment activity on highway projects, which is of concern because nonroad diesel construction equipment is relatively unregulated and is a major contributor to NOX and diesel PM emissions. Estimates of equipment activity are important in order to accurately model the emissions effects of road construction, and construction’s actual contribution to regional emissions inventories, as well as to better select and design appropriate mitigation strategies. To help address this gap in knowledge, construction diaries were collected for thirty recently completed Caltrans projects, sampling six typical Caltrans project types. Equipment activity for every project in the sample is categorized with an equipment category, a project phase category and a percent of project completion category. The equipment categories are primarily the NONROAD construction equipment classes, and the phase categories are aligned with the phases in the UCD Emissions Estimation Model. Using this database, we can then estimate means of equipment use based on type of highway project. There are three deliverables that result from this project. First, a database with analytic capabilities is created that is used to manage the projects in the sample and output the next two deliverables. Second, table output is created for each project that aggregates equipment activity by the above categorizations into easily comprehendible charts. Third, the same types of charts are used to create output tables for the average equipment activity for each project type. These data can be used as crude equipment activity estimation models, or can help quality check predictive models.