Below are brief descriptions of communications products recently developed by the Federal Highway Administration's Office of Research, Development, and Technology. All of the reports are or will soon be available from the National Technical Information Service (NTIS). In some cases, limited copies of the communications products are available from FHWA's Research and Technology (R&T) Product Distribution Center (PDC).

Compiled by Lisa A. Shuler of FHWA's Office of Corporate Research, Technology, and Innovation Management

When ordering from NTIS, include the NTIS publication number (PB number) and the publication title. You also may visit the NTIS website at www.ntis.gov to order publications online. Call NTIS for current prices. For customers outside the United States, Canada, and Mexico, the cost is usually double the listed price. Address requests to:

National Technical Information Service
5301 Shawnee Road
Alexandria, VA 22312
Telephone: 703–605–6050
Toll-free number: 1–888–584–8332
Website: www.ntis.gov
Email: customerservice@ntis.gov

Requests for items available from the R&T Product Distribution Center should be addressed to:

R&T Product Distribution Center
Szanca Solutions/FHWA PDC
700 North 3rd Avenue
Altoona, PA 16601
Telephone: 814–239–1160
Fax: 814–239–2156
Email: report.center@dot.gov

For more information on R&T communications products available from FHWA, visit FHWA's website at www.fhwa.dot.gov, the FHWA Research Library at www.highways.dot.gov/resources/research-library/federal-highway-administration-research-library (or email fhwalibrary@dot.gov), or the National Transportation Library at ntl.bts.gov (or email library@dot.gov).

Leveraging Augmented Reality for Highway Construction
Publication Number: FHWA-HRT-20-038

Augmented reality (AR) is an immersive technology combining computer-generated information with real-world imagery in real time. AR enhances the user’s perception of reality and enriches information content. Challenges in highway construction management and field operations include the lack of real-time and integrated information, gaps between planned solutions and practical implementations, quality assurance, and effective project communications. Three-dimensional (3D) model-based design and construction workflows are becoming more common on highway projects, and the Federal Highway Administration is promoting these and other innovations through its Every Day Counts program and Building Information Modeling efforts.

The increased use of 3D model-based workflows and rapid advancement in computer interface design and hardware make AR a tool for overcoming these construction challenges. Enriched content can help project managers and engineers deliver projects faster, safer, and with greater accuracy and efficiency. This study focused on documenting current AR technologies and applications, with an emphasis on the state of the practice for using AR technologies in design, construction, and inspection applications for highways, and includes a literature review and interviews with researchers and vendors.

The publication is available at www.fhwa.dot.gov/publications/research/infrastructure/pavements/20038/20038.pdf.

Utilizing Mobile Ad Hoc Networks to Enhance Road Safety
Publication Number: FHWA-HRT-20-046

Analyses by the National Highway Traffic Safety Administration concluded connected vehicle innovations could reduce crashes, injuries, and fatalities by 50 percent. There are places and times, however, where there will be a need to supplement connected vehicle systems—for example, in rural areas where there may not be enough traffic for connected vehicle systems to be viable, or during events when crowds may overwhelm systems working well during normal operations.

FHWA’s Exploratory Advanced Research Program supports studies investigating the use of mobile ad hoc networks (MANETs) to enhance road safety for all users. MANETs are a way to communicate on the fly with available hardware and software. MANETs require minimal infrastructure and can be created autonomously as desired. They have been used primarily in military applications and in disaster relief efforts, but have not yet been used for transportation safety.

One scenario involves smartphones from nonmotorized travelers directly sending automatic, periodic geographical broadcast messages via a mobile application to nearby vehicles, which, in turn, send the information to following vehicles. This method eliminates the need to ping other vehicles about the nonmotorized traveler"s location and alerts vehicles to their location more quickly.

Researchers at the University of Virginia are exploring how to deploy MANETs in areas and scenarios with less infrastructure, such as when pedestrians and bicyclists cross at the mid-block and in more rural or remote settings. At the University of Wisconsin—Madison, researchers look to harness MANETs to alert vehicles to pedestrian and bicyclist crossings at intersections through a mobile application.

The publication is available at www.fhwa.dot.gov/publications/research/ear/20046/20046.pdf.

Evaluation of Holes Fabricated Using Plasma Arc Cutting
Publication Number: FHWA-HRT-20-056

This report documents fatigue and tensile test results of steel plates with round holes fabricated using plasma arc cutting. Bridge owners, designers, and fabricators have shown interest in using plasma arc cutting as a more economical alternative to traditional hole fabrication methods. However, a lack of experimental data demonstrating the behavior of plasma-cut holes under fatigue and tensile loading has hindered their use in steel bridge design and fabrication. FHWA initiated the study to categorize the fatigue and static tension resistance of plasma-cut holes in steel bridge members.

Modern plasma-cutting equipment and techniques can produce high-quality holes more economically than drilling and punching. However, design and construction specifications from the American Association of State Highway and Transportation Officials do not permit the use of plasma-cut holes in primary bridge members because of a lack of experimental data demonstrating their fatigue and tensile strength. Additionally, it is uncertain if holes fabricated using plasma arc cutting meet the AASHTO requirements for accuracy of hole size.

This research establishes the design fatigue resistance and assesses the fracture behavior of steel members with plasma-cut holes. Researchers evaluated multiple plasma-cutting processes. Results showed that the fatigue resistance of plasma-cut holes is lower compared to current hole-making methods. The researchers found that open holes fabricated using plasma arc cutting are an AASHTO category E fatigue detail, representing lower fatigue resistance compared to drilled or punched holes. Tensile testing showed certain plasma-cutting processes could cause brittle failure modes in tension members with plasma-cut holes.

The publication is available at www.fhwa.dot.gov/publications/research/infrastructure/structures/bridge/20056/20056.pdf.

Learning About Driver and Pedestrian Behaviors Through Connected Simulation Technology
Publication Number: FHWA-HRT-20-059

As the Nation’s roadways increase in connectivity and complexity, a challenge emerges to maintain road safety and mobility for all roadway users. Examining how vehicles and pedestrians share the road is one key way to improve road safety, especially considering increased pedestrian deaths by motor vehicle crashes. In 2018, there were 6,283 reported pedestrian fatalities due to car crashes, the most since 1990. This report provides a description of the research carried out to improve the understanding of connected simulated technology and how to expand the study of interactions between drivers and pedestrians, impacting the creation of technologies involving safety and mobility.

FHWA’s Exploratory Advanced Research Program has been supporting research examining simulated traffic interactions between drivers and pedestrians to better understand how they communicate with each other and the resulting impacts on driver and pedestrian behaviors. The University of Iowa conducted a research project using real-life drivers and pedestrians along with simulated vehicles and pedestrians in a connected driving simulation. The researchers successfully created a connected simulation environment, linking a pedestrian simulator and a driving simulator by bridging differing software systems—a large technical challenge of the project.

Based on the connected simulation technology, the researchers explored the relationship between glances and gestures pedestrians may make toward oncoming traffic as they attempt to cross a roadway. This study was facilitated using 3D avatars, which the Iowa team customized for the research project. The project resulted in the development of mixed-mode technology with connected driving and pedestrians through the use of graphical avatars, representing the live actions and movements of drivers and pedestrians.

Additionally, the study yielded new methods of scenario control and data analysis suited for multiparticipant simulation research. Although participants stated that most of the time they could not distinguish the real participants from the simulated ones, the results suggest real study participants do behave differently with each other than with simulated pedestrians and vehicles.

The publication is available at www.fhwa.dot.gov/publications/research/ear/20059/20059.pdf.

Coating Performance on Existing Steel Bridge Superstructures
Publication Number: FHWA-HRT-20-065

Steel corrodes when exposed to moisture and oxygen. If left unprotected, some steel used in highway bridge superstructures is highly susceptible to corrosion when exposed to the environment. The corrosion process is significantly accelerated in the presence of salts. Corrosion on highway bridges is predominantly caused by chloride ions from either deicing salts or natural chlorides present in certain environments.

This study evaluated the performance of four coating systems applied on chloride-contaminated steel substrates. The purpose of the study was to identify coating systems that can provide extended service life for steel bridges with minimal surface preparation at a much-reduced cost. The study helps estimate the amount of chloride contamination coating systems can tolerate without significant premature failure.

The chloride contamination levels tested in this study were 0, 20, and 60 micrograms per cubic centimeter. The coating systems tested were two three-coat systems (one with inorganic zinc-rich primer and the other with organic zinc-rich primer), a two-coat system with carbon nanotubes in its zinc-rich primer, and a one-coat system of high-ratio calcium sulfonate alkyd. Coated panels were exposed to two conditions: accelerated laboratory testing and outdoor natural weathering. The three-coat systems had the best corrosion protection performance among the tested specimens. The inorganic zinc primer performed slightly better than the organic zinc primer. The two-coat system demonstrated the highest adhesion strength over all levels of chloride contamination.

The publication is available at www.fhwa.dot.gov/publications/research/infrastructure/structures/bridge/20065/20065.pdf.

To Alert or Assist: Comparing Effects of Different Lateral Support Systems on Lane-Keeping
Publication Number: FHWA-HRT-20-068

Road-departure crashes, in which a vehicle inadvertently drifts off the road, are among the most severe types of crashes, making up 37 percent of highway fatalities. Lateral support systems have the potential to reduce road-departure crashes by decreasing the probability that a vehicle will leave its intended travel lane. Two lateral support systems on the market are lane-departure warning (LDW) and lane-keeping assist (LKA). LDW systems issue a visual, audible, or haptic warning to alert the driver when the vehicle has crossed a lane boundary. LKA systems actively move the vehicle back into its lane by either applying steering torque or light differential braking.

This publication describes an experiment examining the effect of lateral support systems on driving behavior and user acceptance of lateral support systems. The research team used a driving simulator to compare lane-keeping behavior when drivers controlled the vehicle without lateral assistance (manual control) or were assisted by LDW or LKA systems. The goal of the study was to assess the effect of each type of lateral support system on drivers’ lane-keeping ability in different situations and examine driver acceptance of lateral support technology.

This study assessed the influences of lateral support systems on lane-keeping. Participants were divided into three conditions: LDW, LKA, and manual driving. The experiment used simulated wind gusts to induce lane departures throughout the drive. Participants in the LDW condition spent less of the drive outside of their lane, returned to their lane more quickly when a lane departure occurred, and held a more constant position while in their lane. Lane-keeping for drivers in the LKA condition did not match those in the better lane-keeping LDW condition, but the group showed reduced lane-departure durations relative to those in the manual driving condition. Participants in the manual driving condition also showed reduced travel speeds relative to those in the LDW or LKA conditions, suggesting that the difference in lane-keeping was not due to a lane-keeping/speed tradeoff. In fact, participants in the LKA condition maintained similar levels of lane-keeping compared to participants in the manual condition while driving more quickly, indicating LKA improved drivers’ lane-keeping ability. The findings speak to the potential usefulness of lateral support systems for reducing lane departures.

The publication is available at www.fhwa.dot.gov/publications/research/safety/20068/20068.pdf.