The Challenge
In April 2003, we undertoook an extensive project on behalf of the Hawaii Department of Transportation
Highways Division, to provide a comprehensive and up-to-date digital photolog inventory of the state's
entire system of owned and maintained routes. The island group of Hawaii lies approximately 3860km (2400
miles) off the west coast of the US, and has a varied topography of mountainous terrain, desert regions
and tropical rainforests. The project covered six of the eight major islands, Kauai, Oahu, Maui,
Molokai, Lanai, and Hawaii, which together totaled 4000 chainage miles of road. The data was
comprised of digital videolog imagery, including all road features such as bridges, tunnels, and
traffic signals etc., road centerline coordinate data, plus road geometry and pavement information. The
data was to be compatible with the HDOT's existing GIS and engineering software.
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The Solution
Given the topography of islands, a successful result would require a custom configuration of the
Digilog system, an integrated image capture technology engineered to maintain continuous,
accurate positioning information, regardless of terrain and location. The system was modified
as a complete roadway data collection unit, ideally suited to this type of project, where multiple
georeferenced and geocoded data sets are generated simultaneously. Equipped with dual
high-resolution digital cameras, a laser Pavement Profile Scanner (PPS), and a
high-end Position Orientation System with integrated GPS/Inertial technology, the
M20 vehicle was ready to go in a matter of days.
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The Result
With the project underway, the M20 Hawaii system quickly proved to be cost-effective and efficient, and readily
overcame the difficulties associated with the project. There were some stretches of road which were very narrow
and overhung with dense foliage. In these areas, GPS reception was seriously effected and in some places
non-existent. Our POS system's ability to provide continuous and reliable position and orientation information
meant that we were able to map all the transportation routes very effectively. Had we employed GPS technology
alone, a significant amount of digital imagery would not have been georeferenced.
The project was completed in less than 11 months with a comprehensive set of georeferenced data.
This included detailed, camera-generated 1300 x 1030 resolution imagery, full-width pavement scans
to identify transverse, longitudinal and distress profiles, and road centerline, curve and grade data, all
easily integrated into the HDOT GIS database.
Informational Sheets
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road
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