Project 0-6663 Phase 2 involved evaluation of the TxDOT automated visual distress 3D laser system van and three automated systems developed by automated visual distress data collection vendors. The research team selected 20 test sections in the Austin and Waco Districts comprising asphalt concrete pavement, surface treatments, portland cement concrete, and continuously reinforced concrete pavements. Each of the 550-ft-long test sections were subsectioned at 50-ft intervals and were evaluated manually by an experienced Long Term Pavement Performance (LTPP) manual distress rating team and a TxDOT Pavement Management Information System (PMIS) manual distress rating team. In each case the manual raters followed the LTPP or PMIS Rating Manual protocols to identify and measure distress on each test section. In addition, cross slope was measured with the FACE® Dipstick; texture was measured with the circular track meter; and digital crack map images were obtained by manually marking each crack using different colors related to three width categories and then photographing selected 50-ft subsections using a high-end digital camera. These manual measurements provided a baseline for comparison with the TxDOT and vendor automated system data output. The four participants collected automated distress, cross slope, texture, and crack map images during late July and August, finishing on August 30, 2013. Based on previous discussions with TxDOT and the vendors during a webinar held on January 30, 2013, data was reported by TxDOT and the vendors for three time intervals: 1) immediately after data collection with no manual post processing; 2) within 2 business days with minimal post processing; and 3) within 4 weeks with full, manual post processing. The last set of completed data was received in early October, 2013. These data sets were used by the research team to conduct both analytical and visual comparative analysis of output from the four automated systems presented in this report. (Author/publisher)
Samenvatting