Geo Week News

September 29, 2015

An Accuracy Standard for 21st Century Transportation Management


By Robert Dingess, President & CEO, Geospatial Transportation Mapping Association (GTMA)

For more on Robert Dingess’ plan, see his SPAR Insider Podcast interview

An effort is underway to develop a national spatial accuracy standard for the collection of transportation assets, specifically one that mirrors the standards for dynamic maps used by automated vehicle systems. Companies involved in the collection of network LiDAR and photogrammetry for transportation agencies should be paying close attention.

The Digital Transportation Infrastructure (DTI) Asset Collection Standard is to be developed within the transportation subcommittee of the Federal Geospatial Data Committee. This effort is being sponsored by the U.S. Department of Transportation in response to a request by the Geospatial Transportation Mapping Association (GTMA) working in concert with the American Society of Photogrammetry and Remote Sensing (ASPRS) and the Intelligent Transportation Society of America (ITS America). 

The Geospatial Transportation Mapping Association (GTMA) is strongly promoting that the initial DTI spatial accuracy standard be tied closely to the requirements for automated vehicle basemaps (sub decimeter).

Why Link the Dynamic Mapping Standards?
Mirroring the two standards opens the door for fusing state agency data (pavement and bridge condition, friction, retroreflectivity, etc.) with the extensive private-sector LiDAR and photogrammetry data being collected, integrated and updated for use in automated vehicle systems by firms such as Google™, HERE™, Tom-Tom™, etc.

The linkage of these accuracy standards increases the value of both data sets and facilitates the development of accurate and updated statewide and national basemaps. Lessons learned about safety, maintenance and operational improvements from the collection of supplemental pavement and bridge condition data on National Highway System routes could be applied more easily to off-system road networks.


The development of a new national spatial standard not only addresses today’s asset inventory issues, it also positions transportation managers to benefit from hundreds of millions of dollars in private-sector research and development specifically targeted at improving LiDAR, photogrammetry and other ancillary automated vehicle data capture technologies. In addition, transportation managers will benefit from private software developers as they continue to improve systems designed for data extraction and system analysis. All of these benefits come with minimal public sector investment, permitting scarce agency resources to focus on improving how the data is managed, visualized and analyzed to optimize internal systems.

While a number of transportation agencies have used network photogrammetry and LiDAR for asset collection purposes, the private sector investment and public sector interest to promote automated and connected vehicle technologies is driving the demand for broader spatial accuracy standards. A recent international survey of public and private sector decision-makers presented at the 2015 Automated Vehicle Symposium is illustrative. It found that nearly 80% of respondents supported the development of national, and possibly international, digital infrastructure standards. An equally large number supported national governments taking the lead in this effort. Synchronizing spatial accuracy standards for automation and asset management enhances the U.S. position when participating in international standardization efforts.

The ultimate industry goal is to assist agencies in the transition from transportation management to a greater focus on the analytical questions surrounding “what does the data tell us about the system?” With a national spatial standard, we would dramatically enhance the value of all network level data sets (friction, operations, crash).


Assurance for Surveyors
As an aside, while this standardization process addresses a number of key management and safety-data related issues, a secondary benefit of this DTI standard is that it clearly delineates how these data sets can and cannot be used. DTI data should not be used, for example, as a substitute for project surveying. The sub-decimeter relative accuracy that works well for automated vehicle basemaps, asset management, crash safety location audits, and basic modeling and planning activities is simply not accurate enough. My own suspicion is that the excellent work being conducted by Ron Singh at Oregon DOT and Curtis Clabaugh in Wyoming will likely result in more robust standards related to survey class data.

Moving Forward
While USDOT has agreed to facilitate the development of spatial data standards, the standard development process will be carried out by public and private sector professionals. As president of GTMA, it has been a pleasure working with colleagues from ITS America and the American Society of Photogrammetry and Remote Sensing (ASPRS) in support of this effort. As the process moves forward, we would invite all those interested in learning more to attend the GTMA Annual Meeting, November 10-11, 2015 (Washington, DC). We have a number of sessions related to the standard proposal and the USDOT is conducting a “Listening Session” on the “National Standard for Mobile Spatial Data Collection for Transportation Assets” scheduled for the afternoon of November 10th. Both ITS America and ASPRS are incorporating similar discussions as they build their meeting schedules for 2016.

This is an exciting time of transition and change as it relates to transportation management and mobility. This standardization effort is just another step towards a safer and more transparent future.

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