May 7th, 2008
With over 35 years of photolog experience, the Connecticut Department of Transportation (ConnDOT) has continually been a leading-edge user of photolog technology, and a long-time proponent of the usefulness of photologging as a tool in pavement/asset management programs. Since 1994, ConnDOT has operated two ARAN photolog vehicles to maintain a photo record of Connecticut roadways. The long-term goal behind ConnDOT’s photolog program, to improve the value of its photolog inventory and increase dissemination to as many users as possible, has taken a giant step forward with the integration of High Definition (HD) imaging.
With the Federal Highway Administration (FHWA), ConnDOT initiated a research project to improve the quality and distribution of images to its clients. ConnDOT enlisted Fugro-Roadware to reconfigure its ARANs with improved photolog technology. The previous camera system produced a limited image resolution of 640 x 480 pixels. The HDTV camera chosen for the upgrade produces images at a resolution of 1920 x 1080 pixels, yielding detail fine enough for reliable identification of road signs, bridge numbers and utility pole numbers, and stunning overall picture quality.
Another advantage to the HDTV system is the increase in the horizontal field of view. The HDTV camera produces an approximate 90 degree field of view, whereas ConnDOT’s previous digital camera, only an approximate 45 degree field of view. This allowed ConnDOT to eliminate the low resolution, dual camera system previously used in favor of the single HDTV camera. The result was a superior image, with a decrease in imaging equipment, and the number of the collected images cut by half.
ConnDOT’s DigitalHIWAY system distributes the images for desktop viewing across the Department’s local area network to approximately 400 clients including DOT, State Police, and FHWA state headquarters personnel. The Department has realized a significant cost savings, as the use of HDTV photolog images reduces the number of field trips required by personnel.
ARAN’s modular design has allowed ConnDOT to upgrade several times through the years. Most recently, chassis swap upgrades were performed in 2007-2008 to replace aging vehicles, and line scan (1 mm cracking resolution) pavement video will be added in 2008-2009. Additional systems include GPS, POS LV, roughness, rutting, overhead obstruction measurement, and WiseCrax automated distress analysis.