Onsite data collection is essential for estimating onsite productivity, measuring project performance, and tracking large earthmoving operations. This paper presents a web-based system, developed for estimating onsite productivity and tracking earthmoving operations. The paper briefly describes the main components of the developed system and focuses primarily on estimating onsite productivity .The proposed system utilizes spatial technologies including GPS and GIS in addition to Google maps to support its management functions. The proposed system is most suited for large earthmoving projects. GPS is used to automate onsite data collection in near real time and to facilitate information exchange among members of project teams. GIS is employed not only to automate data acquisition, but also to analyze collected spatial data. The developed system has been coded in prototype software using object-oriented programming and Microsoft Foundation Classes (MFC). Real case example of a construction project is analyzed to demonstrate the features of the developed model.