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United States Department of Transportation United States Department of Transportation

Public Roads - January/February 2015

Date:
January/February 2015
Issue No:
Vol. 78 No. 4
Publication Number:
FHWA-HRT-15-002
Table of Contents

Communication Product Updates

Communication Product Updates

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
5301 Shawnee Road
Alexandria, VA 22312
Telephone: 703–605–6000
Toll-free number: 1–888–584–8332
Web site: 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
13710 Dunnings Highway
Claysburg, PA 16625
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 Web site at www.fhwa.dot.gov, the FHWA Research Library at www.fhwa.dot.gov/research/library (or email fhwalibrary@dot.gov), or the National Transportation Library at ntl.bts.gov (or email library@dot.gov).

 

Intelligent Compaction (TechBrief)

Publication Number: FHWA-HIF-13-053

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Intelligent compaction is an innovative pavement construction technology that equips conventional rollers with instrumentation to monitor and control the material compaction process. The technology, which is applicable to both soil/subbase and pavement compaction, provides graphical information that roller operators can use to better manage their operations. This ensures that the entire process provides a uniform compacted area that is achieved more efficiently. This technical brief offers information on the field application of the technology for asphalt pavements.

Thirteen States participated in the study, Accelerated Implementation of Intelligent Compaction Technology for Embankment Subgrade Soils, Aggregate Base, and Asphalt Pavement Materials. Sponsored by FHWA and the Transportation Pooled Fund, the study took place between 2008 and 2010 and aimed to demonstrate and evaluate intelligent compaction technologies. Of the 13 States, 10 participated in the field demonstration of asphalt pavement projects: Georgia, Indiana, Maryland, Minnesota, Mississippi, New York, Pennsylvania, Texas, Virginia, and Wisconsin.

The use of intelligent compaction was a success in all 10 States. Researchers found that intelligent compaction is very effective at achieving the target level of compaction for asphalt pavements while also increasing the uniformity of the compacted material. The roller demonstrations showed that intelligent compaction rollers could track and determine the optimum number of roller passes, monitor the surface temperature of asphalt pavements, and report measurements back to the operator to better control the compaction process. Also, researchers determined that a key factor in achieving uniform compaction in the final product is uniformity in compaction in the underlying layers.

This technical brief is available to download at www.fhwa.dot.gov/pavement/pub_details.cfm?id=920. Printed copies are available from the PDC.

 

Design Criteria for Adaptive Roadway Lighting (Report)

Publication Number: FHWA-HRT-14-051

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About 50 percent of all fatal crashes occur at night, despite nighttime volumes representing approximately 25 percent of all traffic. Roadway lighting is a proven crash countermeasure on highways. With the development of new lighting technologies and a push to reduce the overall energy and environmental impact of lighting, adaptive lighting has become a new movement in the roadway industry.

Adaptive lighting is a design methodology in which the light output of a system adjusts as traffic conditions change. The level of lighting dims when there is little or no traffic on highways, sidewalks, or both. This report provides an approach to selecting and adjusting light levels based on the needs of the driving environment. The document also reviews the background and analysis used to develop criteria for implementing an adaptive lighting system for roadways.

Researchers collected lighting data from thousands of miles of roadway and compared the varying illumination levels, roadway characteristics, and traffic volumes with crash history information. A robust statistical analysis of the underlying relationships among these data revealed the effects and limits of lighting on overall roadway safety.

The researchers found that the relationship between actual lighting levels and safety was not as strong as in situations with no lighting. In other words, current lighting levels may be higher than required for safety on the roadway. By adapting the framework from existing international standards for lighting selection, researchers developed a method to provide both selection criteria for lighting levels and a method for determining how to implement adaptive lighting.

Researchers expect that the results will assist jurisdictions in making sound, safety-based decisions when considering adaptive lighting approaches. This analysis of real-world lighting data is intended to serve as the foundation for future analyses of roadway lighting.

This report is available to download at www.fhwa.dot.gov/publications/research/safety/14051/index.cfm. Printed copies are available from the PDC.

 

Correction

On page 31 in the July/August 2014 issue of Public Roads, a State Farm logo was removed from the photo of a New York State Department of Transportation H.E.L.P. truck without the express permission of the photograph’s owner, Dexter Davis of Travelers Marketing, Inc. Following is the original photo.

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