Using Terrestrial Lidar to Model Wisconsin's Bridges
Providing SIM for the Wisconsin DOT
Continental Mapping recently completed a 3D modeling project for the Wisconsin Department of Transportation (WisDOT) using terrestrial lidar. In addition to mapping services, Continental Mapping staff worked with WisDOT to develop standards and applications for this new technology and aid in site information modeling (SIM) and other applications.
WisDOT surveyors used a Riegl VZ-400 terrestrial lidar scanner to collect scans of six interstate bridges
in Monroe County, and Continental Mapping provided calibration, processing, and final modeling of the data.
Continental Mapping worked closely with WisDOT to develop needed deliverables including planimetric features, accuracies, data file types, and other details. After establishing standard deliverables with the client, Continental Mapping calibrated the multiple lidar point clouds, created bare earth models of the area, and generated a DTM to create vector features and linework. Vertical clearances were measured along beams, paint lines, road crown, and bridge surface.
Deliverables included raw point cloud, bare earth model, DTM data, planimetric CADD features, as well as separate files containing measurements for bridge clearance and bridge deck. All data was delivered in 3D MicroStation V8 DGN format. The project was highly successful and has set a precedent for future WisDOT mapping/modeling projects, and Continental Mapping is looking forward to continuing to share our site and transportation modeling (SIM and TIM) expertise with our clients.