FHWA R&T Now

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GENERAL/ADMINISTRATIVE

FHWA Participates in ATTRI Outreach and Stakeholder Meetings

The Federal Highway Administration (FHWA) and the Federal Transit Administration are co-leaders 

of the Accessible Transportation Technologies Research Initiative (ATTRI), which aims to enable 

independent mobility of travelers with disabilities through the use of intelligent transportation 

systems (ITS) and other innovative technologies. 

Supported by the ITS Joint Program Office and the National Institute on Disability and 

Rehabilitation Research, the initiative focuses on the needs of three stakeholder groups: people 

with disabilities, veterans, and older adults. Targeting four functional disabilities—visual, hearing, 

cognitive, and mobility—ATTRI is working to develop technological solutions to remove barriers to 

mobility and independent travel.

In November, ATTRI representatives participated in meetings with members of the National 

Robotics Initiative; the Interagency Committee on Disability Research (ICDR) and Department of 

Labor; the ICDR/Interagency Committee on Assistive Technology; and Autonomous Robotics for 

Installation and Base Operations. In December, representatives from ATTRI met with Toyota.

To improve mobility and independent travel, ATTRI solutions will leverage advances in vehicle- and 

infrastructure-based technologies, automation, robotics, and wireless communication. ATTRI will 

focus on the following five technology areas: wayfinding and navigation; assistive technologies; 

automation and robotics; data integration; and enhanced human service transportation. In fiscal 

year 2015, ATTRI will be requesting information about potential applications in these areas for 

further development.

To leverage technologies and innovations from Federal ITS and related disability research and 

development, ATTRI works cooperatively with research partners such as ICDR; the U.S. Army Tank 

Automotive Research, Development and Engineering Center; the U.S. Access Board, and other 

public and private organizations.

For more information, contact Mohammed Yousuf, 202-493-3199, mohammed.yousuf@dot.gov.

INFRASTRUCTURE

LTPP Builds Its First Warm-Mix Asphalt Project

FHWA initiated a new Specific Pavement Study (SPS) for monitoring the performance of warm mix 

A news update of research, technology, and development from the U.S. Department of Transportation (USDOT), 

Federal Highway Administration (FHWA)

January/February 2015

FHWA R&T Now
 FHWA R&T Now

technology under the Long-Term Pavement 

Performance (LTPP) Program. The SPS-10 

experiment, “Warm Mix Asphalt Overlay of 

Asphalt Pavement Study,” aims to compare the 

performance of warm mix asphalt (WMA) to hot 

mix asphalt (HMA), both in the short- and longterm. The study will shorten the current 

knowledge gap between the performance of 

WMA and HMA. FHWA is accepting nominations 

for sites from States.

The SPS-10 experiment is designed to explore 

how a set of primary factors influence pavement 

performance. These factors include: the type of 

WMA technology used, the climatic elements of 

temperature and moisture, and traffic loading. 

The SPS-10 projects are overlays of existing 

asphalt pavement. Each project consists of 500 

foot test sections with different overlay 

properties. Projects are required to have three 

core sections: HMA control, WMA produced 

using a foaming process, and WMA produced 

using a chemical additive. For the purpose of 

this study, WMA is defined as asphalt pavement 

produced at 30 degrees Fahrenheit below 

standard HMA production temperatures or 

below 275 degrees Fahrenheit.

In addition to the core sections, State 

departments of transportation may choose to 

include supplemental sections in order perform 

additional research relative to their own 

network. For example, a State may decide to 

study the effects of increased recycled asphalt 

pavement content, decreased overlay thickness, 

or other WMA production methods. All 

materials testing and performance monitoring 

related to the supplement sections will be 

performed by the LTPP team at no cost to the 

State. 

The first SPS-10 project was constructed in the 

fall of 2014 along westbound Interstate 40 in 

central New Mexico, near Santa Rosa in 

Guadalupe County. The project included the 

three core sections as well as two supplemental 

sections selected by the New Mexico 

Department of Transportation. 

For more information, contact Jack Springer, 

202-493-3144, jack.springer@dot.gov. 

LTPP InfoPaveTM 2015 Released at TRB Meeting

In January 2015, at the 94th TRB Annual 

Meeting, the LTPP program launched the 2015 

LTPP InfoPaveTM Web portal. First released in 

January 2014, LTPP InfoPave allows users to 

easily tap into the wealth of pavement data 

available from the LTPP program. It also offers 

findings from data analyses and extensive 

documentation for the many aspects of LTPP 

experimental designs, data acquisition, quality 

control, and data dissemination. 

To reach out to users of the pavement 

engineering community, the LTPP team formed 

an LTPP InfoPave Champions group, which 

consists of representatives from academia, 

industry, and the private sector research

community (stakeholders who stand to gain the 
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most from the Web-based system). Based on 

inputs from the InfoPave Champions group as 

well as other users, the 2015 improved version 

features many enhancements, including:

 Topic-specific visual data selection.

 Improved filters for identifying LTPP test 

sections of interest.

 Section timeline that includes major 

construction events and monitoring 

actions. 

 Visualization of the pavement layer 

properties and distress data over time.

 Access to the C-LTPP data.

 Interactive LTPP Data Analysis Strategic 

plan and research reports.

 Enhanced presentation of LTPP 

documents, tools, and media.

For more information, contact Aramis López, 

202-493-3145, aramis.lopez@dot.gov.

Researchers Complete Forensic Investigation, 

Present Results 

Researchers at TFHRC have completed a forensic 

study into the cause of slippery conditions on an 

asphalt ultra-thin bonded wearing course. On 

December 3, 2014, Terry Arnold and Nelson 

Gibson of FHWA’s Office of Infrastructure 

Research and Development presented findings 

to the Great Smoky Mountains National Park 

Service (GSMNPS). Those attending included 

Alan Sumeriski, GSMNPS Chief of Maintenance; 

Clay Johnson, GSMNPS Acting Chief Ranger; and 

Laurin Lineman, Director of Project Delivery for 

Eastern Federal Lands. 

The research showed that the operational 

deficiency was a result of the aggregate 

properties as well as the application of an 

excessive amount of tack coat. Although the 

aggregate had passed the Micro-Deval abrasion 

test, the study determined the aggregate 

exhibited a propensity for polishing. 

For more information, contact Jack Youtcheff, 

202-493-3090, jack.youtcheff@dot.gov. 

FHWA Discusses UHPC Connections at DDOT 

Workshop

On December 18, 2014, Ben Graybeal, who 

heads FHWA’s Structural Concrete Research 

Program, conducted a workshop for the District 

of Columbia Department of Transportation 

(DDOT). Requested through DDOT’s local 

division office, the workshop focused on ultrahigh performance concrete (UHPC) connections 

for prefabricated bridge elements. Graybeal 

delivered a hands-on presentation, introducing 

the technology, discussing lessons learned, and 

demonstrating common entry points deployed 

by departments of transportation over the past 

decade. 

About 25 individuals attended, including the 

designer and general contractor for a project 

aimed at redecking the 16th Street Bridge over 

Military Road. Currently underway, the work will 

feature accelerated bridge construction 

methods and use prefabricated superstructure 

units. The plan had been to use conventional 

grouted deck-level connections, but the bridge 

owner is now considering a revised connection 

detail that uses UHPC technology, offering the 

benefits of simpler fabrication and construction, 

as well as enhanced long-term performance. 

DDOT learned about the benefits of using UHPC 

technology at an Every Day Counts summit in 

October. 

For more information, contact Ben Graybeal, 

202-493-3122, benjamin.graybeal@dot.gov.

Technical Brief: Nondestructive Inspection 

Protocol for Reinforced Concrete Barriers 

This technical brief summarizes a response to a 

recommendation from the National 

Transportation Safety Board to “expand the 

research and development of nondestructive 

evaluation technologies to develop bridge 

inspection methods that augment visual 

inspections; offer reliable measurement 

techniques; and are practical, both in terms of 

time and cost, for field inspection work; and 

promote the use of these technologies by bridge 

owners.” 
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Researchers considered four nondestructive 

evaluation technologies, including groundpenetrating radar, low-frequency ultrasonic 

tomography, infrared thermography, and digital 

radiography. They conducted laboratory testing 

on two concrete barrier configurations used in 

the Washington, DC, metropolitan area: the Fshape bolt down barrier and the New Jersey 

free standing portable barrier. 

This document is available at 

www.fhwa.dot.gov/publications/research/infras

tructure/structures/14071/index.cfm. For more 

information, contact Hamid Ghasemi, 202-493-

3042, hamid.ghasemi@dot.gov.

Technical Note: Design and Construction of 

Field-Cast UHPC Connections 

Ultra-high performance concrete (UHPC) 

exhibits mechanical and durability properties 

that make it an ideal candidate for use in 

developing new solutions to pressing concerns 

about highway infrastructure deterioration, 

repair, and replacement. Field-cast UHPC details 

connecting prefabricated structural elements 

used for bridge construction have proven to be 

an application that has captured the attention 

of owners, specifiers, and contractors across the 

country. These connections can be simpler to 

construct and can provide more robust longterm performance than connections 

constructed through conventional methods. 

This technical note provides guidance on the 

design and deployment of field-cast UHPC 

connections. It covers common UHPC 

connection concepts; design of field-cast UHPC 

connection details; material and construction 

specifications; construction engineer inspection; 

and a case study featuring the construction of I81 bridges in Syracuse, NY. 

This document is available to download at 

www.fhwa.dot.gov/publications/research/infras

tructure/structures/14084/index.cfm. For more 

information, contact Ben Graybeal, 202-493-

3122, benjamin.graybeal@dot.gov.

Report: The Use of Phosphoric Acid to Stiffen 

Hot Mix Asphalt Binders 

Phosphoric acid exists in different strengths or 

concentrations, with physical forms ranging 

from a clear odorless colorless liquid or a 

transparent solid, depending on the 

concentration and temperature. This report 

offers guidelines for the use of phosphoric acid 

to stiffen asphalt binders for hot mix paving 

applications. Phosphoric acid can be used in 

different ways to modify asphalt binders. It is 

used as an additive to increase the high 

temperature performance grade. It can also be 

used to reduce the amount of styrene butadiene 

styrene polymer needed to meet the Strategic 

Highway Research Program Superpave Plus 

specifications, especially for binders that are 

marginal on the rolling thin film oven test. 

Dispersion of some polymers in asphalt can be 

facilitated by the addition of phosphoric acid. 

The guidelines in this report will be useful to 

producers of asphalt binders, hot mix paving 

contractors, State departments of 

transportation, and local highway agencies.

The document is available at 

www.fhwa.dot.gov/publications/research/infras

tructure/pavements/14086/index.cfm. For more 

information, contact Terry Arnold, 202-493-

3305, terry.arnold@dot.gov.

SAFETY

FHWA Hosts NCUTCD at Turner-Fairbank

On January 9, 2015, the Human Factors Team in 

FHWA’s Office of Safety Research and 

Development hosted the National Committee 

on Uniform Traffic Control Devices (NCUTCD) at 

the Turner-Fairbank Highway Research Center in 

McLean, VA. This biennial meeting brought 

together more than 50 individuals from local 

and Federal agencies, academia, and industry. It 

included presentations from FHWA staff on 

research activities, including FHWA Traffic 

Control Device Pooled Fund Study projects. 

Following the presentations, attendees were 

offered tours of the Human Factor’s Highway 
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Driving Simulator, Field Research Vehicle, 

MiniSimTM, Sign Lab, and the Saxton 

Transportation Operations Laboratory. These 

laboratories have all seen significant upgrades 

since NCUTCD’s last visit in 2012. 

NCUTCD assists in the development of 

standards, guides, and warrants for traffic 

control devices and helps develop practices 

used to regulate, warn, and guide traffic on 

streets and highways. NCUTCD provides 

recommendations to FHWA and other 

appropriate agencies on proposed revisions and 

interpretations to the Manual on Uniform 

Traffic Control Devices (MUTCD) and other 

accepted national standards. 

NCUTCD also develops public and professional 

awareness of the principles of safe traffic 

control devices and practices and provides a 

forum for qualified individuals with diverse 

backgrounds and viewpoints to exchange 

professional information.

For more information, contact Jim Shurbutt, 

202-493-3420, jim.shurbutt@dot.gov. 

OPERATIONS

FHWA Displays Research Vehicle at TRB Annual 

Meeting

FHWA’s Office of Operations Research and 

Development (R&D) recently displayed a vehicle 

from its research fleet at the Transportation 

Research Board’s (TRB) Annual Meeting in 

Washington, DC. One of five Cadillac SRX 

Crossover vehicles, the vehicle is equipped with 

a technology platform to guide connected 

automation research over the next 5 to 10 

years.

The platform enables fully automatic control of 

acceleration and braking, with the flexibility to 

support steering controls for future connected 

automation research. The platform provides 

researcher-friendly access to longitudinal 

control of the vehicle and manufacturerequipped sensors, and it supports software 

development with common tools such as 

MathWorks Simulink and MATLAB. In addition, 

the platform supports vehicle-to-vehicle (V2V) 

and vehicle-to-infrastructure (V2I) 

communications using dedicated short-range 

communications and cellular communications.

Cooperative Adaptive Cruise Control (CACC) is 

the first operational concept to be tested using 

the five-vehicle fleet. Researchers will leverage 

the longitudinal control capabilities and a data 

elements library provided by the platform to 

deliver and implement speed and torque 

commands. The vehicles will also use V2V 

communications to share speed, heading, 

location, and gap information to achieve 

smoother operation in a five-vehicle platoon. 

The resulting CACC functionality of the research 

vehicles can be leveraged by future projects to 

study additional operational, connected vehicle, 

and automation concepts and applications.

For more information, contact Taylor Lochrane, 

202-493-3293, taylor.lochrane@dot.gov.
 FHWA R&T Now

FHWA Initiates Next Phase of Speed 

Harmonization Research

During the summer of 2014, FHWA’s Office of 

Operations R&D led a speed harmonization field 

test with three vehicles in live traffic. Speed 

harmonization is an infrastructure-to-vehicle 

communications method by which speeds of 

vehicles approaching a bottleneck are slightly 

decreased in order to smooth traffic flow, 

reduce stop and go traffic, and slow the onset of 

major congestion.

Under a new project, “Speed Harmonization 

Fundamental Research,” researchers will build 

on experiences and lessons learned from the 

field test. The objective of the task is to develop 

new speed harmonization concepts for testing 

and identify ancillary technologies required for 

testing. The new speed harmonization concepts 

will demonstrate that vehicles can safely 

operate in an automated fashion to provide 

cooperative speed harmonization and provide 

insight into the potential performance benefits 

if more vehicles are equipped with automated 

longitudinal control.

In order to accomplish these objectives, the 

team will revise the speed harmonization 

algorithms developed for the field test and 

conduct additional testing using FHWA’s fivevehicle research fleet. Testing phases will 

include: closed-course verification at TFHRC at 

slow to moderate speeds; a “shadow mode” 

phase in which the vehicles will receive speed 

guidance in live traffic but automated 

longitudinal control will not be applied; and a 

fully automated control phase in which the 

vehicles will receive speed guidance in live 

traffic and automated longitudinal control will 

be applied to adjust speeds.

The FHWA project team for this task includes 

Leidos, California Partners for Advanced 

Transportation Technology, Texas A&M 

Transportation Institute, TORC Robotics, and 

Virginia Tech Transportation Institute.

For more information, contact Dan Dailey, 202-

493-3395, daniel.dailey.ctr@dot.gov.

RECENT PERIODICALS

Public Roads—November/December 2014

This issue includes: A New Approach to 

Improving Travel Times; One Size Doesn't Fit All; 

An Evolving Partnership; Bracing for Hard Times 

Ahead; and Surviving an Interstate Bridge 

Collapse.

It is available online via 

www.fhwa.dot.gov/publications/publicroads/14

novdec/index.cfm.

For more information, contact TaMara McCrae, 

tamara.mccrae@dot.gov.

Innovator: Accelerating Innovation for the 

American Driving Experience—

November/December 2014

This issue includes: VERG Tells Stories with 

Visuals; First Responders Trained Tops 50,000 

Goal; States Innovate!; Aid Demonstration 

Grants Go to Six Projects; Every Day Counts 

Makes Its Mark; and Calendar. 

The issue is available online via 

www.fhwa.dot.gov/hfl/innovator/eversion/issue_45/.

For more information, contact Kathleen 

Bergeron, kathleen.bergeron@dot.gov. 

Links:

Turner-Fairbank Highway Research Center: 

http://www.fhwa.dot.gov/research/

Resource Center: 

http://www.fhwa.dot.gov/resourcecenter/

National Highway Institute: 

http://www.nhi.fhwa.dot.gov/home.aspx

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