• California Department of Transportation (Caltrans)

    Caltrans Subsurface Asset Management Information Tool (SAMIT)

    Sacramento, California, United States

Project Summary


The California Department of Transportation (Caltrans) invested USD 1 million in the development of the Subsurface Asset Management Information Tool (SAMIT) to document underground utilities within state road rights of way, and publish that data for use by design teams in 12 district offices. Intended for use in all highway construction projects, SAMIT helps staff identify where underground utilities are to avoid hitting them in advance of field operations.


Caltrans connected ProjectWise to an Oracle spatial database to make data available via a map-based interface. It used Bentley Map to geospatially locate the utility geometry, and add asset attributes and metadata. Using MicroStation and Bentley Subsurface Utility Engineering software, users can develop 3D subsurface models from the 2D GIS network diagrams for utilities such as gas, electric, water, and communications.


SAMIT will reduce errors and change orders, improve communications with utility owners, accelerate the utility verification process, help resolve utility conflicts, promote job site safety—especially when dealing with gas facilities—and improve project delivery times. By enabling more accurate pre-project planning, SAMIT will also decrease the necessity, time, and cost for utility investigations. Limiting accidental underground utility hits will ultimately reduce construction costs, as well as the litigation frequently associated with such incidents.


ProjectWise provided project collaboration and data search capabilities for a widely distributed team and large volume of data. MicroStation and Bentley Map provided the technology needed to promote standard network utility geometry to the level of intelligent map features with georeferenced attributes. Detailed information included asset type, condition, age, and ownership. The Bentley software also allowed inclusion of legacy data in multiple formats (DGN, TIFF, vector, and spreadsheet).

  • By documenting known subsurface utility locations, SAMIT allows staff to focus on more congested, high-risk areas.
  • Accurately depicting utilities in advertised contract plan sheets reduces the risk that contractors will hit underground facilities and cause costly delays and service interruptions.
  • The next phase of development for SAMIT includes bringing asset data to the field with Bentley Map Mobile.
  • “The interoperability that Bentley provides for CAD and GIS data in MicroStation with Bentley Map enables the extension of engineering data with GIS attributes, for more informed decisions on design and construction projects.”

    Jeffry C. Kepley Senior Engineer California Department of Transportation