Digital Highway Measurement Laboratory (DHML)

Purpose:  To support the research needs of Federal Highway Administration’s (FHWA’s) technical offices by:

• Identifying, developing, and providing in-the-field demonstrations of advanced sensor systems for the collection of data on, over, or under the road.
• Developing state-of-the-art signal processing algorithms to extract actionable information from sensor data streams.
• Identifying and developing ways to visualize sometimes very complex information so that it is useful to the practitioner.
• Technology transfer – Communicating results to the larger community through field demonstrations, and delivering presentations and papers to appropriate audiences.
• Providing independent perspective on road data collection technologies.

Laboratory Description: The DHML is located at the FHWA Turner-Fairbank Highway Research Center (TFHRC) in McLean, Virginia. It includes 1,200 square feet of general shop space, and 240 square feet of separate office space. The working area is characterized by work benches appropriate for the building and testing of electromechanical components. The lab space includes a single-width overhead door for access to a single-vehicle bay where experimental vehicles can be constructed and maintained.

Laboratory Capabilities:  Researchers in the Digital Highway Measurement Laboratory develop sensor and data processing technologies and methodologies for a wide range of data collection challenges. The DHML’s research and development portfolio includes:

• The Advanced Pavement Evaluation Vehicle uses state-of-the-art step-frequency ground penetrating radar to create three-dimensional subsurface maps with which researchers can measure pavement thickness, locate subsurface objects such as re-bar or utilities, and to detect and classify pavement distress such as delamination, voids, and fractures.
  
  

  
  
  The Advanced Pavement Evaluation Vehicle

• The evaluation of the performance limits of traditional inertial profilers.
• The creation of a formal model relating pavement-tire noise to the texture of the pavement surface.
• The Ultra-Light Inertial Profiler, a Segway™-mounted inertial profiler for use on conventional pavement assessment tasks, as well as to conduct assessments of sidewalks in accordance with the Americans with Disabilities Act.
• The Digital Highway Measurement System, an instrumented research vehicle that combined laser scanning sensors, high accuracy nationwide differential global positioning system, and an airline-quality inertial navigation unit, to measure roadway geometry accurately and to build three-dimensional (3-D) maps of features of interest on, over, or beside the road.

Laboratory Equipment:  The laboratory houses the following equipment.

• Computational resources: One Dell T3500 Intel QuadCore 64-bit workstation. Two Dell T3500 Intel QuadCore 32-bit workstations. One Dell T5500 Intel QuadCore workstation running Linux. Internet2 (1 gigabit per second) connection to Argonne National Laboratory Transportation Research and Analysis Computing Center's 1024 core cluster.
• Data "cave": 24 terabyte disk-swappable mass storage for research data.
• Development tools: PGI C++; Matlab with signal processing toolbox; LabWindows/CVI.
• Visualization tools: 3D-DOCTOR; ArcView GIS; GMT (Linux-based open source 3-D visualization software).
• Vehicle dynamics simulation software: CarSim.
• Other applications: Autocad; MathCad.

Laboratory Services: The DHM Laboratory provides sensor and signal processing development and evaluation services in support of research efforts at FHWA offices at TFHRC and elsewhere.