U.S. Department of Transportation
Federal Highway Administration
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Washington, DC 20590
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
This magazine is an archived publication and may contain dated technical, contact, and link information.
|Publication Number: FHWA-HRT-11-004 Date: May/June 2011|
Publication Number: FHWA-HRT-11-004
Issue No: Vol. 74 No. 6
Date: May/June 2011
Below are brief descriptions of communications products recently developed by the Federal Highway Administration’s (FHWA) 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).
When ordering from NTIS, include the NTIS publication number (PB number) and the publication title. You also may visit the NTIS Web site 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
5285 Port Royal Road
Springfield, VA 22161
Toll-free number: 800–553–NTIS (6847)
Web site: www.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
13710 Dunnings Highway
Claysburg, PA 16625
For more information on R&T communications products available from FHWA, visit FHWA’s Web site at www.fhwa.dot.gov, the National Transportation Library’s Web site at http://ntl.bts.gov, or the OneDOT information network at http://dotlibrary.dot.gov.
Publication No. FHWA-HRT-10-075
In January 2010, experts from government agencies, universities, and regulatory and market agencies participated in a workshop to discuss how buying and selling ecosystem services could ultimately lead to a more resilient and sustainable planet. The workshop, Ecosystem Service Markets and Associated Performance Measures, was supported by the FHWA Exploratory Advanced Research (EAR) Program. The fundamental concept of ecosystem service markets (ESM) is that many services an ecosystem provides, such as water quality, flood control, and habitat for endangered species, can be assigned a value and then bought and sold on an open market.
In ESM, the ecosystem services result in a tradable commodity, such as tons of carbon or phosphorus, or a risk management tool, such as insurance against extinction of a species. Some of the workshop participants' long-term vision of ESM is that service providers and buyers can meet in a virtual marketplace that is regulated and approved by agencies with legal authorities under legislation such as the Endangered Species Act and the Clean Water Act.
This fact sheet summarizes the workshop's topics of discussion, including ESM background, benefits, and implementation, and development of a valued ecosystem. The fact sheet also includes information on how advancing ESM could potentially provide the transportation industry with an alternative means of compliance with environmental laws that result in faster permitting, as well as less expensive and better performing mitigation. However, many issues of policy and science must be addressed before such a one-stop shopping market will come to fruition.
Printed copies of the fact sheet are available from the PDC.
Publication No. FHWA-HRT-10-064
More than 25,000 people die each year in the United States in crashes caused by a vehicle drifting or veering out of its lane. Preventing such crashes through a more accurate and reliable lane-keeping system is the challenge addressed in an EAR project launched in 2008: Intelligent Multi-Sensor Measurements to Enhance Vehicle Navigation and Safety Systems. This fact sheet discusses driver-assisted and automated lane keeping, integration of systems data, the key challenge to combining measurements of lane-keeping systems, and future research efforts.
Recognizing the potential of positioning technologies to prevent thousands of highway deaths, FHWA continues to support efforts to improve their reliability and accuracy. In this project, FHWA is attempting to integrate data from a variety of onboard sensing equipment, such as lane detection cameras, micro-electromechanical systems inertial sensors, high-accuracy nationwide differential global positioning systems, and advanced light detection and ranging systems. Although each of these technologies can contribute data to lane-keeping systems, each also has performance limitations. Project researchers are working to fuse the data from a range of sensors to compensate for those deficiencies. The key challenge is that researchers must correct each sensor's specific, individual error source before they can combine the different but complementary measurements.
Following a successful demonstration of enhanced lane-positioning capability, the project will produce a test methodology for industry use. FHWA's goal is to refine and optimize the data integration algorithms for various driving conditions.
Printed copies of the fact sheet are available from the PDC.
Publication No. FHWA-HRT-10-062
Fiscally responsible, safe, life-cycle management of the Nation's bridges depends on reliably predicting their health over time. The goal of the EAR project Development and Demonstration of Systems-Based Monitoring Approaches for Improved Infrastructure Management Under Uncertainty is to create a new framework for infrastructure management and advance the reliability of bridge assessment. This fact sheet discusses development of the new framework, data gathering and integration, use of advanced systems-based analysis methods, and future efforts regarding predicting bridge health.
Effectively managing bridge maintenance, repair, and replacement requires a deeper understanding of how bridges and their components respond to environmental conditions and increased traffic loads. Researchers are using state-of-the-art data mining and analysis techniques to integrate information generated during the design, construction, and maintenance of structures with continuously updated data from a network of monitoring sensors. To monitor bridge components, researchers are using sensor technologies for measuring strain, temperature, displacement, tilt, and vibration, and technologies not traditionally used in bridge monitoring such as video imaging, infrared sensing, pressure gauges, and microphones.
This research could lead to significant cost efficiencies in managing transportation structures, while also reducing the cost of information processing and analysis through automated data collection and evaluation processes. Perhaps most important, FHWA expects the structural health monitoring framework to accelerate advances in performance-based assessments of the condition of transportation infrastructure.
The fact sheet is available at www.fhwa.dot.gov/advancedresearch/pubs/10062/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-10-037
Step frequency ground penetrating radar (SF GPR) technology offers unprecedented subsurface three-dimensional imaging capabilities. Through previous evaluations and reports, FHWA has determined that SF GPR can be applied to evaluate subsurface infrastructure problems. However, due to SF GPR operating principles, system electromagnetic emissions testing is required to ensure the device will not interfere with other systems that use the electromagnetic spectrum (such as the Federal Aviation Administration's radar tracking or radio astronomy). This report provides a comprehensive emissions characterization and evaluation of an SF GPR system.
For this report, researchers characterized and evaluated an SF GPR system to determine whether it can be operated safely in a proposed configuration that includes frequency notching to remove emissions in specific frequency bands. This emissions testing was conducted with several notching configurations turned on and then turned off to enable researchers to evaluate both scenarios.
Results from initial emissions testing showed that the SF GPR met the National Telecommunications and Information Administration (NTIA) criteria for most frequencies, but some emissions frequencies still exceeded NTIA criteria. The researchers made some system adjustments and conducted followup emissions testing using a final system configuration that meets NTIA criteria for intentional emissions. This report describes the testing in detail, along with a proposed coordination procedure between NTIA and system users to ensure appropriate operation.
The report is available at www.fhwa.dot.gov/publications/research/operations/10037/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-10-044
Shared lane markings (also called sharrows) help convey to motorists and bicyclists that they must share the road. The markings create improved conditions by clarifying where bicyclists are expected to ride and by notifying motorists to expect bicyclists on the road. FHWA sponsored a study to evaluate the impact of several uses of shared lane pavement markings. This TechBrief provides a summary of the methodology, site-specific experiments, and findings from the research.
Researchers conducted experiments in Cambridge, MA, Chapel Hill, NC, and Seattle, WA. The experiments specifically dealt with the shared lane marking design—a road marking applied where a complete bike lane cannot be installed. The cities implemented the markings in a variety of situations and collected data on the operating behaviors of bicyclists and drivers in the traffic stream before and after installation.
According to the report, results indicate that the shared lane markings increased operating space for bicyclists. The study also recorded a decrease in the number of bicyclists riding on the sidewalks. More information is available in the corresponding main technical report of the same title (FHWA-HRT-10-041).
The document is available at www.fhwa.dot.gov/publications/research/safety/pedbike/10044/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-10-045
The high intensity activated crosswalk (HAWK) treatment, now called the pedestrian hybrid beacon, where installed at pedestrian crossings, has the potential to achieve a high rate of driver yielding to pedestrians, especially at major arterials with minor street intersections. FHWA recently sponsored a study to evaluate the safety effectiveness of the beacon treatment, and this TechBrief provides a summary of the study's background, methodology, observations, and conclusions.
At a crossing with the pedestrian hybrid beacon treatment, drivers receive multiple cues to emphasize the potential presence of pedestrians. These cues include a unique configuration of the beacon (two red lenses over a single yellow lens), high-visibility crosswalk markings (ladder-style markings as opposed to only two transverse white lines), a stop bar approximately 50 feet (15 meters) from the crosswalk, 8-inch (20-centimeter) solid lane lines between through travel lanes, illuminated "Crosswalk" signs, and school warning signs. When activated, the pedestrian hybrid beacon uses a red indication to inform drivers to stop.
Researchers studied 21 intersections in Tucson, AZ, where the devices were installed and used two reference groups to compare signalized and unsignalized sites. Since the prime objective of a pedestrian hybrid beacon is to provide pedestrians with safe crossing opportunities, researchers collected and compared data on pedestrian crashes. The study reports a statistically significant reduction in pedestrian crashes at sites with the device installed. More information is available in the corresponding main technical report (FHWA-HRT-10-042).
The document is available at www.fhwa.dot.gov/publications/research/safety/10045/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-10-046
Researchers have examined many methods to increase the likelihood of drivers yielding to pedestrians in multilane crosswalks at uncontrolled sites with relatively high average daily traffic. In this study, FHWA specifically examined the effects of side-mounted, yellow, light-emitting diode (LED) rectangular rapid-flashing beacons (RRFBs) at uncontrolled, marked crosswalks on driver yielding behavior. This TechBrief provides details on the research methodology, study results, and conclusions.
Researchers conducted a series of experiments at 22 sites in Mundelein, IL, St. Petersburg, FL, and Washington, DC, to examine the efficacy of RRFBs for increasing driver yielding behavior. The researchers also compared the RRFB with a traditional overhead yellow flashing beacon and a side-mounted traditional yellow flashing beacon. Additional variations of the treatment included mounting more units on a median or pedestrian refuge island and aiming the RRFB system to maximize brightness at a target site.
The results showed that RRFBs are an effective tool for increasing the number of drivers who yield right-of-way to pedestrians in crosswalks at sites where drivers previously did not regularly yield to pedestrians.
The document is available at www.fhwa.dot.gov/publications/research/safety/pedbike/10046/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-10-067
Crosswalk markings provide guidance for pedestrians crossing roadways by defining and delineating paths on approaches. To help identify the relative visibility and driver behavior effects of varying styles and patterns of crosswalk markings, FHWA studied the relative daytime and nighttime visibility of three crosswalk marking patterns: transverse lines, continental markings, and bar pairs. This TechBrief includes information on the background, study approach, results, and recommendations.
For this study, 78 participants drove an instrumented vehicle through a predetermined route on the Texas A&M University campus in College Station, TX. The route provided an open road environment that included portions in a typical college setting (such as sidewalks, buildings, and a sports arena) and roads through the agricultural area of the campus, which are more rural in feel. Roadway lighting was present at each of the crosswalk locations. Using the special vehicle instrumentation, researchers measured and recorded various driving performance data.
The research found that participants gave the continental markings and bar pairs similar ratings, both in the daytime and at night. However, the transverse marking ratings showed a difference based on the light level. The participants gave transverse markings lower ratings during daylight conditions and gave them slightly better ratings, although still worse than continental or bar pairs markings, during the nighttime.
The document is available at www.fhwa.dot.gov/publications/research/safety/pedbike/10067/index.cfm. Printed copies are available from the PDC.
Corrections: In a photo caption in the article "A Majestic Showcase" in the March/April 2011 issue, Governor Jan Brewer should have been listed as a Republican from Arizona. In the article "Sustainable Streets" in the March/April 2011 issue, David Carlson's email address should have been listed as email@example.com. We regret the errors.