Federal Transportation Agencies Research Articles

Application of Satellite-Based Remote Sensing for the Management of Pavement Infrastructure Assets

The long-term monitoring of transportation infrastructure assets at a lower cost and with short mobilization time is of significant interest to both state and federal transportation agencies in the U.S. Because of the significant improvement in spatial and temporal resolution of synthetic aperture radar (SAR) remote sensing systems and a notable reduction in the cost of data acquisition, SAR has now become a viable method to provide economic and rapid condition assessment of transportation assets. A research study was developed and performed to comprehensively perform the inspection and characterization of a pavement surface based on the amplitude of backscattering of an X-band radar. In situ characterization of the test site was first performed using traditional inertial profilers and aerial photogrammetry with unmanned aerial vehicle (UAV) surveys. The results from these in situ methods were compared with the corrected amplitude of the SAR data, which indicated that the distribution of surface roughness values computed from the inertial profiler, UAV, and SAR exhibited similar probability densities at various segmental lengths considered in this study. This suggested that the problematic areas that are evident during in situ characterization can be delineated and quantified based on the normalized radar cross section of the pavement surface. Overall, the outcome of this research exhibits the potential of SAR for future transportation asset management undertakings, and the systematic framework developed as a part of this research could be of significant interest to engineers and transportation practitioners.

Development of Dust Storm Modeling for Use in Freeway Safety and Operations Management: An Arizona Case Study

Extreme weather conditions such as strong winds, hail, heavy rainfall, heavy snowfall, and high air temperature impact roads, traffic, and operational decisions. Strong winds in arid regions may pick up fine dust particles and create massive blowing plumes dramatically reducing the visibility. This reduced visibility severely impairs driving ability causing catastrophic crashes. The purpose of this research was to investigate the impacts of dust storms on freeway safety and operations. Interstates 8, 10, 15, 17, 19, and 40 running through Arizona were studied in relation to dust loading and crash risks. To achieve this, nine severe Arizona dust storms (2009–2016) were modeled using Weather Research and Forecasting (WRF) model coupled with a chemistry module (WRF-Chem). WRF is a mesoscale numerical weather prediction system with a software architecture allowing for parallel computation. When coupled with a chemistry module (WRF-Chem), it could be used to model the fate and transport of the particulate matter. Dust hot spots were calculated based on Getis-Ord Gi* statistical method and were correlated to dust storm caused crashes. It was shown that a positive Gi* accompanied by dust loading of at least 50 kgm–2 will result in a crash with a 90% confidence level. The outcome of this research could be used by local and federal transportation agencies to communicate warnings to drivers for improved safety.

Assessing the utility of TAM, TPB, and UTAUT for advanced driver assistance systems

Advanced Driver Assistance Systems (ADAS) are intended to enhance driver performance and improve transportation safety. The potential benefits of these technologies, such as reduction in number of crashes, enhancing driver comfort or convenience, decreasing environmental impact, etc., have been acknowledged by transportation safety researchers and federal transportation agencies. Although these systems afford safety advantages, they may also challenge the traditional role of drivers in operating vehicles. Driver acceptance, therefore, is essential for the implementation of these systems into the transportation system. Recognizing the need for research into the factors affecting driver acceptance, this study assessed the utility of the Technology Acceptance Model (TAM), the Theory of Planned Behavior (TPB), and the Unified Theory of Acceptance and Use of Technology (UTAUT) for modelling driver acceptance in terms of Behavioral Intention to use an ADAS. Each of these models propose a set of factors that influence acceptance of a technology. Data collection was done using two approaches: a driving simulator approach and an online survey approach. In both approaches, participants interacted with either a fatigue monitoring system or an adaptive cruise control system combined with a lane-keeping system. Based on their experience, participants responded to several survey questions to indicate their attitude toward using the ADAS and their perception of its usefulness, usability, etc. A sample of 430 surveys were collected for this study. Results found that all the models (TAM, TPB, and UTAUT) can explain driver acceptance with their proposed sets of factors, each explaining 71% or more of the variability in Behavioral Intention. Among the models, TAM was found to perform the best in modelling driver acceptance followed by TPB. The findings of this study confirm that these models can be applied to ADAS technologies and that they provide a basis for understanding driver acceptance.

Primer on Patentability and Use of Ideas Developed by Contractors Performing Work for State and Federal Transportation and Local Planning Agencies

The U.S. patent system has a number of implications for federal, state, and local departments of transportation (DOTs) and other transportation agencies. For example, contractors who develop inventions with the use of federal funds are typically allowed to patent the inventions, but the federal government retains a license to use the invention, or to have another contractor use the patented invention on behalf of the federal government. This statutory framework allows federal transportation agencies to directly fund an invention, and then later hire different contractors to use or improve the invention, without paying royalties to the original contractor, who may have patented the invention. Furthermore, even when the federal government does not own a license to a particular invention, the federal government can authorize its contractors to use patented inventions, and the patent owner’s only remedy is to seek a reasonable royalty in the U.S. Court of Federal Claims, as the federal contractor is immunized from infringement claims. Different schemes apply to state and local DOTs, which may be authorized to obtain patent protection for inventions developed by their contractors or employees. Where federal grant funds are used in the performance of a state or local contract, the federal scheme probably applies — granting patent rights to the contractor and a nontransferable license to the federal government. However, there are unique considerations when an invention is made on a federally funded state DOT contract, because it is the state DOT (rather than the federal funding agency) who has contracted with the inventor, and the contracting state DOT may be more likely than the federal funding agency to need a license for its other contractors to use or improve the invention on behalf of the state DOT. The fact that the federal government obtains a license to use an invention does not mean that the invention can be used royalty-free on future federally funded projects by the state DOT whose contractor invented it, or by other state DOTs. Furthermore, unlike federal transportation agencies, state and local DOTs do not have the ability to authorize infringing use by their contractors. As a result, contractors for state DOTs are vulnerable to infringement lawsuits by patent owners, even as the state DOT itself is immune from suit. This article summarizes these and other patent law topics as they apply to federal, state, and local transportation agencies.

Citizen Activism and Freeway Revolts in Memphis and Nashville

In the 1950s, the Tennessee State Highway Department planned Interstate-40 segments through Overton Park in Memphis and a central city black community in Nashville. Although slow to develop, freeway revolts emerged in both cities by the mid-1960s. Citizen activists in each city battled local municipal regimes and downtown business allies, Tennessee state road engineers, and bureaucrats in several federal transportation agencies. In Memphis, the anti-freeway organization Citizens to Preserve Overton Park, led by relentless activist and park preservationist Anona Stoner, outwitted opponents for years with appeals, demands for reviews or modifications, and eventually litigation that ended up, successfully, in the U.S. Supreme Court. In Nashville, the Interstate-40 Steering Committee, a group of black professionals led by Fisk University professor Flournoy Coles, cobbled together an opposition movement at the last moment. Their legal argument that the I-40 expressway through the North Nashville black community represented racial discrimination against an entire community seemed logical in Nashville but failed in the Supreme Court. The goal of this article, then, is to reflect on the impact of the Interstates on American cities, as well as to analyze how and why one anti-freeway movement succeeded and another failed.