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January/February 2001
Internal FHWA Partnership Leverages Technology and Innovation (continued)
Collaboration in Pavement Studies and Construction
There has also been a great deal of cooperation in pavement studies. The Pavement Surface Analysis (PSA) Laboratory at TFHRC developed ROSAN (Road Surface Analyzer) for research in the area of general pavement surface texture measurement.One variant of ROSAN, ROSANv, combines a high-speed, high-resolution laser sensor, distance pulser, bumper-mounting hardware, data acquisition card, and a notebook computer in one neat portable package. The hardware is controlled by a TFHRC-written, Windows-based program. ROSAN is mounted on the bumper, and it can measure macrotexture and record other features, such as faulting, tining, grooves, and joints. ROSANv can collect sample data at one-millimeter intervals at almost 100 kilometers per hour (60 mi/h). In its very first field trial to ascertain if the system was reliable, end-of-load aggregate segregation was unexpectedly identified on some asphalt pavement. ROSANv has since been used in aggregate segregation, tire/pavement-texture noise generation, and texture/skid number studies.
ROSANv is a portable, vehicle independent, 12-volt powered, high-speed, noncontact, pavement macrotexture measurement system developed at TFHRC. ROSANv exceeds the requirements of ASTM E1845-96, Standard Practice for Calculating Pavement Macrotexture Mean Profile Depth" using laser based systems. The entire package, excluding the notebook computer, fits in a wheeled protective case than can be checked as baggage. ROSANv package consists of the wheeled protective case, SELCOM 2008 laser Optocator, interface module electronics box, PCMCIA data acquisition card, cables, mounting bracket, temporary bumper hitch, small inverter (in place of battery operation of computer), and 3-way power splitter. Commercial version includes an accelerometer for profile measurement as input to smoothness (PRI) and roughness (IRI and RN) indices in addition to macrotexture measurements. TFHRC and Surfan Engineering and Software Inc. had a Cooperative Research and Development Agreement (CRADA) to continue research, development, and implementation of a commercial ROSAN device (ROSANprofile). Surfan has expanded ROSAN's capabilities beyond texture measurements to include road profiling for smoothness and roughness measurements.
Like many states, FLH is developing performance-related specifications for pavements. ROSAN is a natural fit for FLH because it is easily transported, vehicle independent, and addresses multiple aspects of pavement surface condition. FLH is currently evaluating the ROSANprofile software and is working with Surfan to customize ROSANprofile to fully meet FLH's requirements.
"Federal Lands has benefited directly from the ROSAN research initiated by the PSA Lab," said Dennis Sixbey, PSA Lab manager and ROSAN project manager. "First, ROSANprofile will likely become one of Federal Lands' standard devices for smoothness, roughness, and texture measurements. Secondly, through close interaction with Surfan in evaluation and customization of ROSANprofile, Federal Lands has become more intimately knowledgeable on noncontact measurements and simulation/analysis algorithms used in texture, smoothness, and roughness measurements to a greater degree than most end-users of texture and profiling equipment. Third, the safety and productivity of field staff are increased because no traffic control is needed and results are available almost in real time. Objectivity, accuracy, repeatability, and speed of processing of the data are increased by multiple orders of magnitude."
The ROSAN team for FLH includes (from left) Cal Frobig (WFL), Laurin Lineman (EFL), Kim Pellegrini (EFL), Keith Wong (EFL), Beau Williams (CFL), and Roger Surdahl (CFL). Not pictured is Bruce Wasill (WFL)
The U.S. Park Service has a pavement problem at the intersection of 15th Street and Constitution Avenue in Washington, D.C. The standard asphalt mix for the District of Columbia is failing at this intersection, and the pavement is rutting prematurely. The Park Service asked FLH to help, and FLH requested the assistance of RD&T.
"TFHRC took the D.C. mix design and evaluated it using accelerated performance tests," said Tom Harman, RD&T's Asphalt Pavement Team leader. "With the data from the evaluation, we convinced the District and Federal Lands to try a modified asphalt mix for the first time."
"We can do research in an ivory tower, but taking and applying research in the real world and having the opportunity to try what we think are best practices is very beneficial to us," Harman added.
Other Articles in this Issue:
Safe Plowing - Applying Intelligent Vehicle Technology
Improving Roadside Safety by Computer Simulation
Using the Computer and DYNA3D to Save Lives
LS-DYNA: A Computer Modeling Success Story
Preservation of Wetlands on the Federal-Aid Highway System
Internal FHWA Partnership Leverages Technology and Innovation
New Applications Make NDGPS More Pervasive
Center for Excellence in Advanced Traffic and Logistics Algorithms and Systems (ATLAS)
National Work Zone Awareness Week (April 9 to 12) - Enhancing Safety and Mobility in Work Zones
