James R. Mekemson, Ph.D., P.E.
Senior Research Engineer
Dr. Mekemson has 33 years of experience as a transportation research engineer. He has worked 13 years in the area of vehicle based data acquisition system design for various pavement and roadway measurement systems and in the development of techniques for analysis of the acquired data. Much of the work was conducted under contract to the Federal Highway Administration within the Turner-Fairbank Highway Research Center. Development projects have included FHWA’s Digital Highway Measurement van, Ultra-Light Inertial Profiler, PRORUT2 (Research Profiler), and ROSAN (Road Surface analyzer). These systems have been used in a number of research, demonstration, and applied projects and applications.
Selected projects:
DHM: A developer of the FHWA Digital Highway Measurement (DHM) vehicle data acquisition system, and post-processing modules for roadway alignment measurement, pavement marking analysis, edge of pavement, and roadside profile. Sensors include NDGPS, Inertial Navigation Unit (Commercial aircraft quality), scanning laser, macrotexture lasers, profiling lasers, accelerometers, infrared sensors, optical triggers, DMI, encoders, high resolution cameras and others. First vehicle based system able to measure 3D roadway alignment at highway speed to accuracy sufficient for rehabilitation design. In addition to the use of the system for research purposes, the DHM was used by FHWA in a number of FHWA Federal Lands Highway Division (FLHD) research application projects. With the addition of two IR cameras and a step-frequency GPR, the system was used for an FHWA Office of Pavement Technologies research application project for a state where distresses were appearing in two-year old pavement on an interstate highway.
ULIP: Developed the FHWA ULIP series (Ultra-Light Inertial Profiler) based on a SEGWAY Human Transporter. One system has been in use for over three years in the measurement of texture at Auburn University’s National Center for Asphalt Technology. Latest version is for the measurement of sidewalks for America with Disabilities Act (ADA) compliance. Sensors include GPS, vertical gyroscope, height/texture laser, accelerometers, optical triggers, and DMI. City of Bellevue Washington is using it to measure all 336 sidewalk miles for compliance to the ADA. Critical measurements include cross slope, grade, and surface profile for bump analysis. Currently adding a scanning laser for 3D texture measurements.
Accelerometer sensitivity study: Developed the hardware and data acquisition and analysis software for the FHWA FLHD sponsored inertial profiler accelerometer sensitivity study involving a number of different accelerometers operating at a wide range of vehicle speeds. Laboratory and extensive field studies were conducted. Results of study were used by an ETG group in their work to develop inertial profiling provisional standards for AASHTO and to identify future research needs in inertial profiling.
Warp and Curl: Developed the Windows-based PCC Warp and Curl data acquisition and basic analysis software for measuring at highway speeds pavement slab shape changes (sub-millimeter) due to diurnal temperature changes using the FHWA PRORUT2 (Inertial Profiler) system hardware with a pavement temperature sensor added. Dr. Mekemson’s colleague, Dr. Gagarin, performed the subsequent signal analysis to extract the data required for the data mining effort. Received Best Conference Paper Award at the 7th International Conference on Concrete Pavements – Orlando, Florida, USA – September 9-13, 2001.