Below are brief descriptions of reports recently published by the Federal Highway Administration's (FHWA) Office of Research, Development, and Technology. All of the publications are available from the National Technical Information Service (NTIS). In some cases, limited copies of the publication are available from the Research and Technology (R&T) Report Center.

Please Note: Contact NTIS for current pricing at www.ntis.gov or at Telephone: (703) 605-6000.

When ordering from NTIS, include the NTIS PB number (or publication number) and the publication title. You may also 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 asking price. Address requests to:

National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: (703) 605-6000

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

R&T Report Center, HRTS
Federal Highway Administration
9701 Philadelphia Court, Unit Q
Lanham, MD 20706
Telephone: (301) 577-0906
Fax: (301) 577-1421

For more information on research and technology publications coming from FHWA, visit the Turner- Fairbank Highway Research Center's (TFHRC) Web site at www.fhwa.dot.gov/research/tfhrc/, FHWA's Web site at www.fhwa.dot.gov, or the OneDOT information network at http://dotlibrary.dot.gov/.

Rest Area Forum: Summary of Proceedings
Publication No. FHWA-RD-00-034

More than 70 representatives attended the Rest Area Forum in Atlanta, Ga., in June 1999. Representatives from federal and state departments of transportation, the motor carrier industry, the private truck stop industry, and commercial drivers and safety advocates attended the forum. The purpose of the meeting was to identify issues and find solutions to provide adequate, safe parking for commercial drivers and their vehicles.

Forum participants discussed issues such as safety and security, parking needs at privately owned truck stops, alternative parking sites, locations of public rest areas and privately owned truck stops, financial support of truck stops, time limits, and trucker education about driver fatigue. Participants made recommendations to address each of these issues.

The NTIS number is PB2000-103836.

Common Characteristics of Good and Poorly Performing AC Pavements
Publication No. FHWA-RD-99-193

This report documents the analysis and findings of a study conducted to identify the site conditions and design/construction features of flexible pavements that lead to good performance and those that lead to poor performance. Data from the Long Term Pavement Performance (LTPP) test sections were used, along with findings from previous and ongoing analyses of LTPP data.

Since there was no known criteria for identifying performance expectations over time, a group of experts convened to establish criteria. Separate criteria were developed for performance with regard to roughness (IRI), rutting, transverse cracking, and fatigue cracking.

The NTIS number is PB2000-102377.

Extrapolation of Pile Capacity From Non-Failed Load Tests
Publication No. FHWA-RD-99-170

Load testing a static pile to failure is the ultimate way to examine the capacity and integrity of deep foundations. Since the procedure is expensive and time-consuming, it is often substituted for the application of a load to a certain factor (most often two) times the contemplated design load. This method is not preferred because only a proof test is carried out, while the ultimate capacity and actual factor of safety remains unknown. Therefore, researchers need to find an easier, accurate way to reliably estimate the ultimate bearing pile capacity for non-failed load tests.

Researchers proposed a practical analytical method that is capable of extrapolating the measured load-settlement relations beyond the maximum tested load. The proposed procedure, along with two other possible methods, was evaluated. The procedures are examined through a database of 63 driven piles load-tested to failure.

The NTIS number is PB2000-102368.

LTPP Pavement Maintenance Materials: PCC Partial-Depth Spall Repair Experiment, Final Report
Publication No. FHWA-RD-99-153

The Strategic Highway Research Program (SHRP) H-106 maintenance experiment and the FHWA Long- Term Monitoring (LTM) of Pavement Maintenance Materials Test Sites project studied the repair of partial- depth spalls in concrete pavements.

The purpose of partial-depth spall repair is to restore a pavement's structural integrity, improve its ride quality, and extend its serviceable life. This report documents the entire portland cement concrete (PCC) partial-depth spall repair study, including the installation of 30 unique repair types (i.e., combinations of patching material and patching method) at four different test sites, the laboratory testing of experimental repair materials, and the seven-year performance monitoring of the various partial-depth repairs. It also discusses the results of comprehensive statistical analyses conducted on material performance and laboratory testing data. The results of a detailed cost-effectiveness analysis are also presented.

The NTIS number is PB2000-100915.

LTPP Pavement Maintenance Materials: SPS-4 Supplemental Joint Seal Experiment, Final Report
Publication No. FHWA-RD-99-151

The SHRP Specific Pavement Studies (SPS)-4 preventive maintenance experiment was established to determine the benefits and cost-effectiveness of concrete maintenance activities, such as joint sealing and slab undersealing. Since 1989, several test sites have been constructed throughout the United States for this purpose. This report documents the entire SPS-4 supplemental joint seal study, including the installation of 29 unique joint seal treatments, the laboratory testing of experimental sealant materials, and the multi-year performance monitoring of the various joint seal treatments. It also discusses the results of comprehensive statistical analyses conducted on sealant material performance.

The NTIS number is PB2000-100914.

Time to Corrosion of Reinforcing Steel in Concrete Containing Calcium Nitrite
Publication No. FHWA-RD-99-145

In 1996, Florida DOT received 18 slabs of concrete from FHWA. These slabs were cast in 1980 using predetermined amounts of calcium nitrite in chloride-contaminated reinforced concrete. These specimens were compared to reinforced slabs with no admixed calcium nitrite. The upper and lower steel mats were connected and remained connected until 1996. Various tests were conducted on these slabs until June 1987, after which all testing was terminated and the slabs remained outdoors. The findings of this study indicated that calcium nitrite is effective in slowing the onset of corrosion in chloride-contaminated reinforced concrete as long as the ratio of chloride to nitrite does not exceed 0.9.

The NTIS number is PB2000-102363.

Crash Models for Rural Intersections: Four-Lane by Two-Lane Stop-Controlled and Two-Lane by Two-Lane Signalized
Publication No. FHWA-RD-99-128

This report describes the collection, analysis, and modeling of crash and roadway data for intersections on rural roads in California and Michigan for the years 1993-1995. Three classes of intersections are considered: (1) three-legged intersections with major road four-lane and minor leg two-lane stop- controlled; (2) four-legged intersections with major road four-lane and minor legs two-lane stop-controlled; and (3) signalized intersections with both major and minor roads two-lane. Data were acquired from the Highway Safety Information System, state and federal photologs, and field work at all intersections. The field work included morning and evening traffic counts by movement and vehicle type, as well as alignment measurements out to 244 meters along the major road. The final data sets consist of 84 three- legged intersections, 72 four-legged intersections, and 49 signalized intersections. Other variables collected include Roadside Hazard Rating, number of driveways, channelization, intersection angles, and speed limits.

The NTIS number is PB2000-102367.

Modern Computational Environment for Seismic Analysis of Highway Bridges
Publication No. FHWA-RD-99-114

This report describes the architecture, design, and implementation of ALADDIN, a new high-level scripting language and tool kit for interactive matrix and finite element analyses of structures. In ALADDIN, finite element computations are viewed as a specialized form of matrix computation, matrices are viewed as rectangular arrays of physical quantities, and numbers are viewed as dimensionless physical constants.

ALADDIN's programming language uses only a small number of keywords, supports a variety of familiar looping and branching constructs, and links to libraries of matrix and finite element functions. It has been designed so that files are readable and consist of a friendly, intuitive syntax rather than a table of numbers. Engineers are provided with the flexibility of modifying problem parameters and problem- solving algorithms without recompiling source codes.

The NTIS number is PB2000-102375.