PUBLIC ROADS

www.fhwa.dot.gov Autumn 2019

Evolution or 

Revolution?

Alternative Cementitious Materials

Also in this issue:

SHRP2 Eases Utility Challenges

U.S., South Korea Share Knowledge

EDC-4 Advances Innovation
PUBLIC ROADS

Autumn 2019 www.fhwa.dot.gov Vol. 83, No. 3

—featuring developments in Federal 

highway policies, programs, 

and research and technology—

ARTICLES

Alternative Cementitious Materials: 

An Evolution or Revolution?  

by Kimberly Kurtis, Prasanth Alapati, and Lisa Burris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Taking new approaches to using ACMs will help to develop durable nextgeneration infrastructure as economically as possible.

Meet the SHRP2 Utilities Bundle  

by Maggie Kasperski . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Utility conflicts can present major delays, costs, and headaches for transportation 

agencies, but avoiding them just got easier.

Are You an Innovation Champion?  

by Julie Zirlin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

State and local agencies embrace new norms throughout the fourth round 

of Every Day Counts.

Learning from International Perspectives  

by Jihan Noizet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

The United States and the Republic of Korea have a long-standing program 

to exchange transportation knowledge and ideas.

Speeding Up Bridge Deck Evaluations  

by Hoda Azari and Mehdi Rashidi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

FHWA researchers developed a robotic air-coupled acoustic system to reduce 

traffic delays and increase safety when collecting data to assess condition.

PAGE 10 

PAGE 16 

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DEPARTMENTS

Guest Editorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Hot Topic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Innovation Corner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Along the Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Internet Watch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Training Update . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Communication Product Updates . . . . . . . . . . . . . . . . . . .27

COVER—To find ways to identify new infrastructure applications, FHWA performed various studies on alternative cementitious materials. Those materials are proving to be an 

area of interest for potential use in transportation construction and maintenance. For more information, see “Alternative Cementitious Materials: An Evolution or Revolution?” 

on page 4 in this issue of Public Roads.

Petrographic images © Robert Moser, U.S. Army Engineer Research and Development Center, Vicksburg, MS. 

Microscope image © iStock.com/Kkolosov.
PUBLIC ROADS • AUTUMN • 2019 • 1

U.S. Department of Transportation

Elaine L . Chao, Secretary

Federal Highway Administration

Nicole R . Nason, Administrator

Office of Research, Development, and Technology

David Winter, Acting Associate Administrator

Shana Baker, Director, Office of Corporate 

Research, Technology, and Innovation Management

Maria Romstedt, Editor-in-Chief

Lisa A . Shuler, Distribution Manager

Editorial Board: 

T . Everett, T . Hess, H . Kalla, M . Knopp, 

A . Lucero, G . Shepherd, C . Walker, D . Winter 

Editorial Contractor:

Arch Street Communications (ASC), 

Publication Management 

N . Madonick, A . Jacobi, A . Martinez, 

K . Vangani , C . Ibarra

Editorial Subcontractor:

ICF, Editorial 

C . Boris, A . Sindlinger, J . Sullivan

Design Contractor:

Schatz Strategy Group, Layout and Design 

R . Nemec, L . Sohl, C . Williams

Public Roads (ISSN 0033-3735; USPS 516-690) 

is published quarterly by the Office of Research, 

Development, and Technology, Federal Highway 

Administration (FHWA), 6300 Georgetown Pike, 

McLean, VA 22101-2296 . The business and editorial 

office of Public Roads is located at the McLean address 

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to the article.

GUEST EDITORIAL 

A Century of 

Accomplishment

As summer heat gives way to changing 

leaves and cooler temperatures, we are 

 easing back into the season of 

pumpkin spice lattes, trick-or-treating, and 

the end of daylight saving time. Autumn is 

an appropriate time to look back with pride 

on all that FHWA has achieved—not just this 

year, but over the last 100 years. 

On July 7, 1919, a convoy of Army trucks 

left Washington, DC, bound for the Presidio 

in San Francisco, CA. The purpose of the 

trip was to test whether the country’s roads 

could handle long-distance emergency movements of motorized Army units across 

the Nation. After 62 days and 3,251 miles (5,232 kilometers), the convoy—which 

included a young Lt. Col. Dwight D. Eisenhower—made clear the need for a system 

of well-built, well-maintained roads and bridges. The official report of the U.S. War 

Department chronicled 230 motor incidents of the convoy and concluded that the 

existing roads were “absolutely incapable of meeting the present day traffic require

ments.” Decades later, President Eisenhower’s experience on that grueling journey 

led to the creation of the Interstate Highway System.

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A century after that historic journey, we continue to find new ways of improving 

our roads, including a host of technological advances that promise to make the U.S. 

highway system safer and more efficient. 

This issue of Public Roads highlights many such innovations. From alternative 

cementitious materials (see “Alternative Cementitious Materials: An Evolution or 

Revolution?” on page 4) to robotic air-coupled acoustic arrays (see “Speeding Up 

Bridge Deck Evaluations” on page 19) and the unprecedented success of the 

Cooperative Automation Research Mobility Applications (CARMASM) initiative (see 

“FHWA Grows Its CARMA Vehicle Fleet by Four” on page 2), FHWA is building 

pathways to the future.

In July 2019, FHWA representatives met with industry leaders to discuss 

CARMA, which is a multiparty effort to get automated vehicles to work together. 

Since July 2018, when FHWA first made it available as open-source software on 

GitHub, CARMA has been making it possible for academia, industry, and public 

agencies to work together on problems they cannot solve alone. While proprietary 

information is still protected, seeing onetime competitors teaming up to address 

challenges is encouraging. 

This issue of Public Roads also showcases innovations that will shape the 

future of the Nation’s roads and advances that got us to this point, such as those 

featured in round four of the Every Day Counts program (see “Are You an 

Innovation Champion?” on page 12) and the second Strategic Highway Research 

Program (SHRP2). 

FHWA’s SHRP2 program makes tools available to help transportation 

professionals manage their utility programs more effectively. Utility Investigation 

Technologies, Identifying and Managing Utility Conflicts, and 3D Utility Location 

Data Repository are SHRP2 products that help transportation agencies nationwide 

address the challenges of underground utilities. For more information, see “Meet 

the SHRP2 Utilities Bundle” on page 10.

The accomplishments of the last century are just the beginning. We can take 

pride in our advancements and anticipate with excitement the successes that await 

us in the years ahead.

Thomas D. Everett

Executive Director

Federal Highway Administration
HOT TOPIC

FHWA recently expanded its CDA fleet by four new passenger 

vehicles. The four different makes and models are shown below. 

All use the third phase of CARMA (CARMA3).

Source: FHWA.

2 • PUBLIC ROADS • AUTUMN • 2019

FHWA Grows Its CARMASM Vehicle Fleet by Four 

by Taylor Lochrane and Laura Dailey 

Automation is transforming mobility. Cooperative driving 

automation (CDA) supports and enables automated vehicles 

to cooperate through communication between vehicles, 

infrastructure devices, and road users, such as pedestrians, 

bicyclists, and scooters. CDA has the potential to improve 

transportation efficiency, facilitate freight movement, increase 

productivity, and save billions of dollars in the reduced need 

to increase roadway facilities. Most importantly, CDA has the 

potential to reduce crashes caused by human error and 

save lives.

The U.S. Department of Transportation is committed to 

facilitating this new era of transportation innovation and 

safety. To this end, the Federal Highway Administration 

developed the Cooperative Automation Research Mobility 

Applications PlatformSM and CARMA CloudSM (collectively 

referred to as CARMASM). CARMA supports the research and 

development of CDA features in support of transportation 

systems management and operations (TSMO).

Enabling Cooperative Driving Automation

CARMA is a multimodal effort among FHWA, the Federal 

Motor Carrier Safety Administration, the Intelligent 

Transportation Systems Joint Program Office, the Maritime 

Administration, and the Volpe National Transportation 

Systems Center. Together, the agencies work to facilitate 

collaboration, research, and testing in cooperative automation.

The CARMA Platform enables cooperative research 

functionality for an automated driving system. CARMA Cloud 

makes it possible for the roadway to provide information to 

support safe operation for new TSMO strategies.

Developed to be vehicle and technology agnostic, CARMA 

uses open-source software and an agile software development 

process. The latest version of CARMA is available on GitHub, 

a web-based repository and version control system for 

computer code that includes features for code review, 

documentation, and collaboration. CARMA supports industry 

collaboration and expands upon existing automation 

capabilities to reduce research and development time and 

advance cooperative automated driving technology.

Automated Vehicles Working Together 

Over the summer, FHWA added four new passenger vehicles 

to its CDA fleet. These vehicles use the third phase of 

CARMA (CARMA3), which was released in mid-July 2019. 

CARMA3 features:

• AutowareTM, open-source software designed for 

autonomous driving, which provides capabilities for 

localization, motion planning, and obstacle detection 

and avoidance.

• Mobileye®-integrated roadway sensing devices, as well as 

environment sensing with light detection and ranging 

(LiDAR), radar, and video.

• Level 2 automation steering and speed control while 

maintaining lane position.

• Basic safety message (BSM) broadcasts using 

CARMA data.

• Operation on three different types of passenger vehicles 

with three different brands of controller modules.

The CARMA3 vehicle fleet includes two sport utility 

vehicles, one minivan, and one mid-size sedan. These four 

vehicles expand FHWA’s testing capabilities and demonstrate 

how connected automated vehicles can work together through 

communication and cooperation. The vision of CARMA is to 

transform transportation, improving efficiency and safety 

through automated vehicles working together.

The additional vehicles expand FHWA’s ability to 

research transportation systems management and 

operations use cases.”

‘‘

— Brian Cronin, director of FHWA’s Office of Safety and 

Operations Research and Development

The CARMA3 vehicles will hit the road in 2020 to conduct 

further research, testing, and demonstrations.

For more information, visit https://highways.dot.gov/research 

/research-programs/operations/CARMA.

Taylor Lochrane, Ph.D., P.E., is a technical 

program manager for enabling technologies in 

FHWA’s Office of Operations R&D. Laura Dailey

is a contracted communications manager at FHWA’s 

Saxton Transportation Operations Laboratory. 

Preview the new vehicle fleet at the Transportation Research 

Board’s Annual Meeting in January 2020. 
PUBLIC ROADS • AUTUMN • 2019 • 3

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INNOVATION CORNER

Filling Funding Gaps

by Mark Sullivan 

Value capture recovers a portion of increased land values from landowners who 

benefit directly, resulting in a more equitable distribution of the monetary benefits 

of well-performing transportation facilities. 

Source: FHWA.

Current conditions and changing demands across the Nation 

necessitate innovative thinking to finance infrastructure 

improvements that are vital to helping communities thrive. 

Value capture helps communities complete projects before 

they otherwise might be able to and is one method for State 

and local highway agencies to pay for infrastructure needs. 

“Freight traffic is on the rise, connected and autonomous 

vehicles will become a reality soon, and communities are 

demanding accommodations for all mobility modes such as 

walking, biking, automobiles, and transit,” says Thay Bishop, 

senior program advisor for the Federal Highway 

Administration’s Center for Innovative Finance Support. 

“These demands require forward-thinking approaches to 

financing transportation projects.” 

Value capture is the process of capturing a portion of 

the value generated by an infrastructure investment to pay 

for some of that investment or to reinvest those funds for 

constructing and maintaining new infrastructure. Transpor

tation improvements often increase the value of nearby land, 

benefitting landowners and developers. Value capture tech

niques harness a portion of the increased property values to 

pay for the improvement or for future transportation 

investment.

“FHWA is working to help State and local highway 

agencies fill funding gaps by increasing awareness of the 

potential use of value capture approaches that can provide 

funding for transportation investments,” says Bishop.

How Value Capture Works

When the link between transportation improvement and the 

ability to monetize the value it creates is possible, State and 

local highway agencies can employ value capture techniques. 

Essentially, value capture is a financial real estate (land-use) 

and transportation opportunity transaction.

Value capture techniques take several forms. The most 

common mechanisms in the United States are air rights, 

impact fees, joint development, land value tax, negotiated 

exactions, sales tax districts, special assessments, tax increment 

finance (TIF), and transportation utility fees (TUFs). 

In any form, value capture enables the public sector to 

share in a portion of the increased land value to build, 

maintain, or reinvest in the transportation system. Public 

investment in transportation assets that improve access and 

make surrounding locations more desirable benefits owners 

of adjacent properties through greater land value and other 

economic impacts.

Value Capture in Action 

Many States—such as California, Colorado, Florida, Georgia, 

Massachusetts, Missouri, Ohio, Oregon, Pennsylvania, Texas, 

Virginia, and the District of Columbia—are using value 

capture options successfully. 

In Oregon, for example, the City of Newberg was one of 

the first agencies in the Nation to fund pavement maintenance 

projects through TUF. TUF is a financing mechanism that 

treats the transportation system like a utility in which residents 

and businesses pay fees based on their use of the transporta

tion system rather than taxes based on the value of property 

they occupy. The City of Newberg had planned reconstruction 

of four blocks of East Fifth Street from River Street to 

Wynooski Street. However, by 2016, available annual revenues 

of $600,000 from existing State gas tax receipts and Federal 

funds exchange fell far short of the projected $2.5 million 

needed. In response, the city adopted a TUF in May 2017 to 

generate an estimated $1.2 million annually to help close the 

$1.9 million gap.

In another example, the Pennsylvania Department of 

Transportation leveraged several funding mechanisms such as 

private contributions and TIF to construct a new interchange 

along Pennsylvania Route 33 in Palmer Township. TIF is a 

value capture revenue tool that uses taxes on future gains in 

real estate values to pay for new infrastructure improvements. 

A development agreement set out responsibilities for payment 

of the improvements with approximately $13.6 million paid by 

the private developer and $27.4 million in public improve

ments. The public improvements were financed in part by 

bonds issued against a tax increment levied on the properties 

within the improvement district.

In round five of Every Day Counts (EDC-5), FHWA is 

providing support and technical assistance to State and local 

public agencies interested in pursuing financing options 

available through value capture. For profiles of real-world 

projects, see www.fhwa.dot.gov/ipd/value_capture/project_profiles.

For more information, visit www.fhwa.dot.gov/ipd 

/value_capture, or contact Thay Bishop at 404–562–3695 

or thay.bishop@dot.gov.

Mark Sullivan is director of the Center for Innovative Finance 

Support in FHWA’s Office of Innovative Program Delivery. 
4 • PUBLIC ROADS • AUTUMN • 2019

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An Evolution or Revolution? 

Taking new approaches to using ACMs will help to develop durable 

next-generation infrastructure as economically as possible.

by Kimberly Kurtis, Prasanth Alapati, and Lisa Burris

The Nation’s deteriorating infrastructure 

requires an estimated investment of 

$2 trillion, according to the American 

Society of Civil Engineers. With close to 

$100 trillion needed to address global 

infrastructure demands, a revolutionary 

approach to infrastructure design, 

construction, and maintenance is 

critical. Because of its wide availability 

at low cost and its use in a vast range 

of infrastructure applications—includ

ing roadways and bridges, pipes and 

spillways, nuclear power structures and 

dams, among others—concrete will 

play a central role in meeting the infrastructure needs for future generations. 

The need for infrastructure investment represents an enormous 

opportunity to rethink concrete 

design and construction. Will this 

be an evolution or a revolution? 

Increasingly, non-portland cements, 

or alternative cementitious materials 

(ACMs), are of interest because of their 

potential to reduce the environmental 

footprint of concrete and their poten

tially advantageous special properties. 

Traditionally, transportation engineers 

largely used ACMs in specialty applica

tions that take advantage of the materi

als’ unique performance characteristics. 

Examples include use in small-scale 

repairs where rapid set and strength 

development are needed, for winter con

struction where high heat of hydration 

is advantageous, and in industrial settings 

where chemical resistance is required. 

The special properties of ACMs, which 

vary depending on composition, can 

also facilitate new construction methods 

and significantly increase service life, 

achieving enhanced durability under a 

range of aggressive environments. 

“It’s important for the transporta

tion industry to examine the evolution 

of ACMs from materials used in niche 

applications to materials that can be 

scaled up and used as alternatives to 

traditional portland cement concrete,” 

says Richard Meininger, a research highway engineer with the Federal Highway 

Administration’s Pavement Materials 

Team in the Office of Infrastructure 

Research and Development. “ACMs 

also have potential for some revolution

ary applications—applications that 

go beyond conventional construc

tion. These opportunities are ripe 

for advancement of ACM usage in 

next-generation infrastructure.” 

Specimen 1 Specimen 2

Specimen 3 Specimen 4

FHWA performed both laboratory and field studies on ACMs. These images are from the petrographic 

analysis of the test specimens, which aimed to identify any internal damage, discoloration, freeze/thaw 

action, or other modes of deterioration.

© Robert Moser, U.S. Army Engineer Research and Development Center, Vicksburg, MS.

What are ACMs? 

Agreement on a comprehensive def

inition for binders used as alterna

tives to portland cement has been an 

evolutionary process itself. In defining 

“alternative cementitious materials,” some 

of the questions the technical commu
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PUBLIC ROADS • AUTUMN • 2019 • 5

nity tackled included: Should this term 

encompass materials that are produced 

without any heat-treatment or without 

calcination? Should it include binders 

that do not include hydrated minerals 

among their reaction products, as con

ventional cements do? Should the term 

encompass blended cements that contain 

portland cement as a component, along 

with other mineral phases not typically 

found in portland cement? What about 

blends of phases found in portland 

cement, but at different proportions? 

An American Concrete Institute 

(ACI) committee on ACMs has determined the answer to each of these ques

tions is “yes.” ACI now broadly defines 

an alternative cement as “an inorganic 

cement that can be used as a complete 

replacement for portland or blended 

hydraulic cements, and that is not 

covered by applicable specifications for 

portland or blended hydraulic cements.” 

By the ACI definition, ACMs in

clude: (1) clinkered materials, such as 

calcium aluminate cement (CAC) and 

calcium sulfoaluminate cement (CSA), 

which are thermally processed similarly 

to conventional portland cement; (2) 

calcined materials, such as magnesium 

phosphate cement (MPC) and magne

sium oxychloride cement (MO), which 

require lower production temperatures 

that do not result in new phase forma

tion during manufacture; and (3) nonclinkered materials, such as alkali- or 

chemically-activated silicates or aluminosilicates (AA), including geopolymers. 

Calculated phase compositions for ordinary portland cement (OPC) 

compared with six commercially available ACMs: two calcium aluminate 

cements (CAC), one ternary blend containing CAC, two calcium 

sulfoaluminate (CSA) cements, and one magnesium phosphate cement 

(MPC). The ACM compositions characterized here are examples and do 

not represent in a general way the compositions of the entire class of that 

type of ACM or ACMs in general.

© Prasanth Alapati, Georgia Institute of Technology (Georgia Tech).

These micrographs of four commercially produced ACMs show 

microstructures for the unreacted powders (left) and pastes after 56 

days of reaction (right) for (a) a calcium aluminate cement, (b) a calcium 

sulfoaluminate cement, (c) a magnesium phosphate cement, and (d) a 

chemically activated aluminosilicate (fly ash). Notations show common 

phases and oxides identified in each material. The magnification varies 

from 250 times to 600 times.

© Prasanth Alapati, Georgia Tech.

Chemical Compositions 

And Reactions

ACMs encompass a broad range of 

compositions and can include materials 

and mineral phases not found in conven

tional portland cement, as well as those 

containing typical portland cement phases 

at different relative quantities. A phase 

is a homogeneous substance that has a 

fixed composition and uniform chemical 

and physical properties. For example, a 

recent Exploratory Advanced Research 

(EAR) project funded by FHWA exam

ined phase compositions for six com

mercially available ACMs, among others, 

and compared them to ordinary portland 

cement (OPC). Some key research results 

for ACM concrete produced from a 

subset of these cements are as follows. 

In general, like portland cement, 

clinkered and calcined ACMs react 

with mix water over time to 

form various products that 

lead to set and ultimately 

bind the aggregates together. 

While OPC is dominated by 

tricalcium silicate (C3S) with 

more minor amounts of 

calcium aluminate phases and 

hydrates (reacts with water) to 

form calcium silicate hydrates 

(C-S-H) as the primary binding 

phase, ACM products fluctuate 

considerably because of 

their varying composition. 

Generally, CACs are mainly 

calcium aluminate (CA) 

and react to form hydrated 

calcium aluminate phases. 

CACs can also be combined 

with OPC, typically along 

with some calcium sulfate, in 

a ternary blended cement. 

CSA cements contain 

relatively large fractions of 

ye’elemite (C4A3S), along with 

phases also found in OPC, 

including belite (b–C2S) and 

calcium sulfates. Like portland 

cements, CSA cements react 

to form C-S-H and ettringite, 

but the relative amount of 

ettringite formed in CSAs is 

considerably greater and the 

reaction to form C-S-H occurs 

more slowly. This is why 

researchers found unhydrated 

belite persisting in the reacted 

cement paste microstructure 

at 56 days of moist curing. 

Finally, MPC can have a 

wide range of magnesium-rich 

compositions. The MPC in 

the EAR study was dominated 

by magnesium oxide and 

potassium phosphate, but 

also contained Wollastonite 

(CaSiO3). That MPC reacted 

very rapidly to form potassiumstruvite (K-struvite), a hydrated 

mineral phase (KPM2H12). 

In activated systems, 

the mix water conveys ions 

that promote dissolution of 

minerals and reprecipitation of 

products. The products of the 

reaction may or may not be 

hydrated. ACMs that rely on 

chemical or alkali activation, 

rather than thermal processing, 

are typically largely composed 
6 • PUBLIC ROADS • AUTUMN • 2019

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of reactive silicates or aluminosilicate 

phases (for example, fly ash, ground 

glass, calcined clay, and slag) that are 

finely divided and contain glassy or 

amorphous phases. These precursor 

materials vary greatly in composition 

and may or may not contain calcium. 

In addition, many precursors are 

byproduct materials, which contribute 

to the sustainability of activated ACM 

concrete. In one example from the EAR 

study, a precursor based on Class C 

fly ash, a coal-combustion byproduct, 

was reacted to form sodium-containing 

aluminosiliceous gels (N-A-S-H) with 

some containing calcium (C-N-AS-H) derived from the fly ash. These 

products bind aggregate together and 

provide strength and impermeability 

in activated systems, which is similar 

to the way C-S-H functions in OPC. 

In all ACMs, as in OPC, reactions 

occur over time and contribute to 

setting, strength development, and im

permeability. The reaction rate depends 

on ACM fineness, composition, and 

environmental conditions. The products 

formed and resulting microstructure 

depend on these parameters, as well as 

the water-to-binder ratio. Appropriate 

water-to-binder ratio to achieve desired 

performance varies by material. Because 

the specific gravity of ACMs may be 

lower or higher than OPC—a range 

of 2.53 to 3.13 was measured—select

ing an appropriate water-to-binder 

ratio requires strong consideration. 

Mix proportions by volume may be 

more appropriate for ACM concrete.

For more details on the chemical 

composition and reaction of the various 

common ACMs, see www.fhwa.dot.gov 

/publications/research/ear/16017/index 

.cfm or www.fhwa.dot.gov/publications 

/research/ear/16017/16017.pdf.

Contributions to Sustainable Construction

Many ACMs have an advantage over 

OPC with respect to their environmental 

footprint because of their variances 

in composition and processing. For 

example, manufacturing CSA and CAC 

cement clinker can result in perhaps 

15 to 50 percent reductions in carbon 

dioxide (CO2) emissions, compared 

with OPC, based on the differences 

in their composition. The reductions 

derive from decreases in the relative 

amount of calcium carbonate feedstock and from lower temperatures 

during clinkering or calcining, or the 

avoidance of thermal processing. 

Blending with other less energyintensive mineral phases (for example, 

calcium sulfates, or limestone)—such 

as in CSA or ternary blends of CAC, 

OPC, and calcium sulfate (CACT)—may 

result in further reductions in embodied 

CO2 because of dilution. Other ACM 

formulations, such as geopolymers or 

other activated aluminosilicates, do 

not require calcination. As a result, the 

embodied CO2 in these systems can be 

quite variable, even among ACM classes. 

The embodied CO2 for these mixtures 

is primarily a function of the activating 

solution, which varies considerably based 

on type and quantity of aluminosilicate 

precursors (and whether they include 

byproduct or recycled materials). 

Additional opportunities exist to 

further enhance the sustainability of 

next generation infrastructure through 

the use and development of ACMs. For 

example, advances in the manufactur

ing and composition of ACMs can 

lead to further savings in greenhouse 

gas emissions and energy required to 

produce ACMs. More immediately, 

increased strength can result in de

creased section size, with a potential for 

decreased materials usage. In addition, 

increased durability further contributes 

to enhanced sustainability and can 

help offset initially higher materials 

costs through longer service life.

ACM Properties

The special properties of ACM compositions vary considerably by material. 

Rapid setting, rapid strength develop

ment, higher ultimate strength, improved 

dimensional stability, reduced heat of 

hydration, and increased durability in 

aggressive environments are some of 

the special properties found in ACMs. 

For example, alkali-activated materi

als are known for their thermal stability 

and fire resistance, and MPCs exhibit 

rapid set and high early strength. Some 

CAC formulations are known for their 

superior resistance to acid, sulfate attack, 

and mechanical abrasion. Some CSA 

systems are associated with improved 

dimensional stability and resistance to 

freeze-thaw and sulfate attack. Other 

ACMs, such as some CSAs rich in belite, 

may exhibit substantially slower strength 

development than OPC. However, 

some ACMs may not possess adequate 

corrosion, carbonation, or sulfate 

resistance, and so users must be aware 

of the associated strengths and weak

nesses of each cement in addition to 

the needs of the project at hand. 

FHWA expects to publish a project 

report that will provide substantial new 

information on ACM performance 

later in 2019. The information will aid 

materials and transportation engineers 

in the selection of appropriate 

ACMs for specific applications.

CO2 Emissions for ACM and Other Binder Technology Relative to OPC 

Cement or Binder Relative CO2

Emissions Source

Portland Cements 1 Scrivener, 2004

Calcium Sulfoaluminate Cements 0.5–0.85 Roux, 2013 and Chen, 2012

Calcium Aluminate Cements 0.53 Bizzozero, 2014

Magnesium Phosphate Cement* 0.55 Wagh, 2013

Activated Aluminosilicate Binders** 0.44–0.64 Mclellan, 2011

*High emissions associated with dead-burned magnesia products result from the very high calcination 

temperatures required (2800°C), as well as the large quantity of carbon dioxide resulting from chemical 

transformation of MgCO3 precursor material into MgO. However, magnesia cements derived from other raw 

materials sources may result in reductions in carbon dioxide emissions, even relative to portland cement. 

**Emissions result from chemical activator manufacture and transportation only. 

Evolutionary Applications 

In a survey conducted by the American 

Association of State Highway and 

Transportation Officials in 2014, 

about half of the State departments 

of transportation (DOTs) responding 

reported they had field experience using 

ACMs. CSA cements were the ACM 

most commonly used, as reported, and 

applications primarily were for repair 
PUBLIC ROADS • AUTUMN • 2019 • 7

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The California Department of Transportation (Caltrans) placed ACM pavement on 

California State Route 60W to the State Route 71S interchange in 1997. After 17 years 

of continual heavy traffic loads, the ACM pavement showed good performance. 

Caltrans noted some surface wear and minor joint spalling in some sections. 

© Kimberly Kurtis, Georgia Tech.

as patches, closure pours, joint repairs, 

partial to full-depth concrete pavement 

repair, and overlays. These applications 

take advantage of the rapid set and 

shrinkage compensation effects associ

ated with many CSA formulations. 

According to the same survey, CACs 

were the next most commonly used 

ACMs. Example CAC applications in

cluded full-depth pavement replacement 

and joint replacement—applications 

facilitated by CAC’s rapid strength de

velopment. However, States considering 

using CAC for high-strength applica

tions should exercise caution. Unlike 

OPC, which gains strength over time, 

CAC early strength can be decreased 

by half. This significant strength loss 

is because of conversion of original 

metastable hydration products to more 

stable hydration products, leading to an 

increase in porosity and permeability.

Some State DOTs also reported 

using MPCs and AAs, primarily for 

repair because of their rapid set 

characteristics (that is, their ability to 

set more rapidly than OPC). MPCs 

are among the most expensive of the 

ACMs, and therefore, some States 

reported a preference for other ACMs 

in applications where feasible. 

Generally, most DOTs respond

ing to the survey reported that their 

ACM repairs were performing well. 

For example, full-depth CSA concrete 

pavements placed in the Los Angeles, 

CA, area showed only minimal abra

sion and joint spalling after 17 years in 

service. However, some DOTs noted 

cracking and scaling issues in some 

locations. Because the DOTs primarily 

used the materials in repair applications, 

it is difficult to assess if the observed 

distresses are related to the material 

itself or to underlying design, overload

ing, site, or environmental issues. 

More recently, ACM use in trans

portation infrastructure has evolved, 

beyond the relatively small-scale and 

repair applications most common in 

recent decades. For example, research

ers from the University of Arkansas 

and University of Oklahoma have cast 

structural prestressed concrete sections 

with CSA cement. The cement’s rapid 

early strength development makes earlier 

prestress release possible, providing time 

savings that could translate into faster 

bed turnover. Improved dimensional 

stability with CSA cements can also 

benefit prestressed concrete construc

tion by minimizing prestressing losses 

associated with shrinkage in OPC. 

Others have explored ACM use 

in ultra-high performance concrete 

(UHPC). CAC in UHPC is envisioned 

for applications requiring high tem

perature resistance. As an example, 

foamed geopolymer concrete has been 

developed in the lab and deployed in 

the field using similar technology as 

used for foaming OPC concrete. The 

highly aerated geopolymer provides 

good fire resistance and acoustic 

properties with the potential for 

operational energy savings and a lower 

environmental footprint com pared 

to conventional foamed concrete. 

Revolutionary Applications

Special properties found in ACMs also 

have facilitated exploration of more 

revolutionary applications. For example, 

ACMs with advantageous rheological 

properties (such as high viscosity, highyield stress, and shear thickening), rapid 

set, and rapid strength development may 

be well-suited for emerging construction 

methods such as three-dimensional (3D) 

printing. CSAs, CACs, and geopolymers 
8 • PUBLIC ROADS • AUTUMN • 2019

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have each been used in 3D printing 

demonstrations in concrete and mortars. 

Some MPCs show good biocompat

ibility, and researchers are exploring 

3D printing approaches to develop 

synthetic bone scaffolds with them. 

Shortages and increasing variability 

in fly ash supplies may require alternative 

means for enhancing durability in new 

construction. In particular, additional 

means are needed to guard against alkalisilica reaction (ASR) and ACMs may play 

an important role. Despite containing 

substantial amounts of alkali as reac

tants, geopolymers have demonstrated 

resistance to ASR. To mitigate damage in 

an existing ASR-affected bridge deck in 

Alaska, contractors placed 

a 0.75-inch (1.9-centime

ter) MPC overlay on top 

of the damaged concrete. 

Because of the very 

rapid—almost instanta

neous—set associated 

with MPC, the contractors 

employed a specialized 

pumping and mixing 

setup for the installation. 

In addition, ACMs 

may play a role in meet

ing infrastructure needs 

as humans become a 

multiplanet species. The 

National Aeronautics and 

Space Administration 

(NASA) has already 

funded research, performed by astronauts 

aboard the International 

Space Station, exploring 

how OPC hydration is 

affected in microgravity. 

NASA recently concluded a nationwide 

3D printed habitat challenge, inspiring 

university-based teams to conceptualize 

and demonstrate concrete construction 

on other planets. Many of the teams 

formulated their concrete composi

tions to make use of the available 

extraterrestrial minerals, including 

silicon-rich basalt, magnesia, and al

kalis common in the Martian crust. 

This graph shows the compressive strength development in CAC, CSA, 

and AA concrete mixtures compared to OPC.

© Prasanth Alapati, Georgia Tech. 

ACMs with Varying Dosages of Set Modifiers

Cement or Binder Retarder (dosage) Setting Time (minutes)

Initial Final

Portland Cement - 105 250

Calcium Sulfoaluminate Cement - 16 28

Citric acid (0.5%) 67 125

Calcium Aluminate Cement - 456 550

Magnesium Phosphate Cement - 11 15

Sodium borate (14%) 60 105

Researchers added retarding admixtures, including citric acid and sodium borate, to slow hydration in CSA and 

MPC formulations to meet the desired 1-hour set time. CAC required no retardation.

© Prasanth Alapati, Georgia Tech.

Upscaling ACMs 

The recent FHWA EAR study explored 

more “earthbound” expanded ap

plications for ACMs. In this project, 

researchers comprehensively assessed 

and compared commercially available 

CSA, CAC, MPC, and AA to OPC. 

The researchers compared the materials 

in terms of their early age behavior, 

mechanical properties, and durabil

ity. The objective of the project was 

the upscaling of ACM concrete for 

transportation infrastructure applica

tions, particularly where construction 

could be possible using conventional 

batching, transportation, placement, 

and finishing methods to minimize the 

need for additional capital investments.

Performance goals for more 

than a dozen commercial ACMs 

that researchers initially considered 

included: (1) at least 1 hour working 

time before set, (2) maintaining 3-inch 

(7.6-centimeter) slump after 1 hour of 

mixing, and (3) a 3500 psi minimum 

compressive strength at 7 days and 

at least 5000 psi at 28 days of age. 

Extending set to at least 1 hour 

proved challenging for some formula

tions. Extending set time is important 

for use of conventional, rather than 

volumetric, mix trucks and for trans

portation of fresh concrete from batch 

facilities to job sites. Some ACMs, 

such as some of the CACs considered, 

set after 1 hour, without the need for 

set-retarding admixtures. For other 

ACMs, with appropriate admixture use, 

researchers were able to achieve the set 

and slump retention goals for CSA, AA, 

and MPC materials. All ACM concrete, 

with the exception of MPC, achieved 

the target slump. Overall, the MPC 

required substantial intervention to slow 

its very rapid hydration kinetics, making 

it challenging to achieve all performance 

metrics with the same mixture design. 

Rate of compressive strength devel

opment varied considerably among the 
PUBLIC ROADS • AUTUMN • 2019 • 9

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materials examined, but all six materials 

that met the workability requirements 

also met the required strength targets at 

both 7 and 28 days. CAC achieved the 

highest early strength, as well as highest strength until 28 days. The slightly 

lower CAC strength at 56 days signals 

the onset of the conversion reaction, 

which will lead to substantial strength 

loss over time in CAC. Conversion oc

curs when the initially formed hydration 

products revert to more stable, more 

dense phases, leading to increases in 

porosity, which is detrimental to strength 

and increases permeability. The AA 

composition was most similar to the 

OPC in strength development, both in 

terms of rate and in ultimate strength. 

CSA formulations showed the greatest 

variability, likely because of the varied 

proportions of ye’elemite, belite, and 

calcium sulfate among the CSAs tested.

Constructability: ACM 

Concrete Slump

Researchers tested the ACM 

concrete slump for these seven 

specimens, which include OPC, 

two CSAs, CACT, two CACs, 

and MPC.

© Prasanth Alapati, Georgia Tech. 

Future Outlook for ACM Usage

Magnesia-based ACMs, such as Sorel 

cements, have existed since the mid1800s. But, advances in low-energy 

magnesia-based cement production are 

among the most promising developing 

ACM technologies. The dichotomy 

between the historical use of ACMs 

and the potentially “game-changing” 

innovative uses demonstrate the intrinsic 

conflict for growing utilization of all 

ACMs. That is, while ACMs are familiar, 

they are also ever-changing, with new 

formulations facilitating advances in 

rheology and mechanical properties, 

in durability, and in sustainability. 

The technological advances increase 

the value for ACM usage in a broader 

range of applications, including those 

involving emerging construction 

methods and in extremely aggressive 

environments. These advances then 

facilitate new applications—even poten

tially in extraterrestrial environments. 

What is holding back the broader 

acceptance and application of ACMs? 

For conventional infrastructure applica

tions, ACM usage is limited because 

it is not well-addressed in existing 

standardized tests or in design guidelines, standards, specifications, or 

codes. Until ACMs are addressed by 

these means, the risk associated with 

their use will limit their application to 

conventional small-scale applications 

and to demonstration and pilot projects. 

“The growing acceptance of 

performance-based specification is one 

avenue for broader acceptance and uti

lization of ACMs,” says Gina Ahlstrom, 

leader of the Pavement Materials Team 

in FHWA’s Office of Infrastructure, 

Office of Preconstruction, Construction, 

and Pavements. “With the information 

gathered from FHWA’s EAR project 

and ACI’s ACM committee and ASTM 

International’s new subcommittees addressing ACM usage, there’s promise 

that new ACM technology will increas

ingly find a more facile path to applica

tions in infrastructure construction.” 

Richard Meininger, Pavement Materials 

Team, Office of Infrastructure R&D, 

is the FHWA point of contact for this 

research. For more on ACM, contact 

Richard.Meininger@dot.gov or 202-493-3191.

Kimberly Kurtis is a professor in 

Georgia Tech’s School of Civil and 

Environmental Engineering and 

School of Materials Science and 

Engineering. Kurtis leads the FHWA 

EAR project described in this article. 

Prasanth Alapati is a Ph.D. candidate in 

the School of Civil and Environmental 

Engineering at Georgia Tech.

Lisa Burris, Ph.D., is an assistant 

professor in the Department of 

Civil, Environmental, and Geodetic 

Engineering at Ohio State University. 

The authors gratefully acknowledge the 

contributions of EAR team members 

Tyler Ley at Oklahoma State University, 

Robert Moser at the U.S. Army Engineer 

Research and Development Center, 

and Neal Berke at Tourney Consulting 

Group, along with their teams.

Please contact Richard Meininger or 

Kimberly Kurtis for a list of available 

publications, including reports, execu

tive summaries, and technical papers. 

Kimberly Kurtis can be reached at 

kkurtis@gatech.edu. 
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The Oregon Department of Transportation (ODOT) 

used Multi-Channel Ground Penetrating Radar 

instrumentation as part of the SHRP2 R01B Utility 

Investigation Technologies product.

© ODOT.

MEET THE SHRP2 UTILITIES BUNDLE

Utility conflicts can present major delays, costs, and headaches for transportation agencies, but avoiding them just got easier.

by Maggie Kasperski

Each time a shovel hits the ground 

on a transportation project, a 

utility strike is possible. After all, 

more than 35 million miles (56 million 

kilometers) of known underground 

utilities exist in the United States 

and many more remain unidentified. 

Telephone and internet cables, electric 

and gas lines, and pipes (both large 

and small) are all at risk when a trans

portation agency digs into the earth. 

The best way for a transportation 

agency to avoid utility strikes is to 

know exactly what lies underground at 

a given location. Agencies need every 

possible advantage to detect and manage utility conflicts. Enter the second 

Strategic Highway Research Program 

(SHRP2), which created a collection 

of tools for transportation agencies 

that address common transportation 

challenges—including utility loca

tion—through a partnership between 

the Federal Highway Administration, 

the American Association of State 

Highway and Transportation Officials, 

and the Transportation Research Board. 

After years of research, 63 products 

were born out of SHRP2, each tested 

by State departments of transportation 

(DOTs) through the Implementation 

Assistance Program (IAP). The IAP 

provided States with financial as

sistance and technical expertise to 

see if SHRP2 products helped save 

time, money, and lives by addressing 

common transportation problems.

Often, the inability to properly lo

cate utilities costs State DOTs time and 

money because of related delays and 

inaccuracies. To help solve the utility 

location issue, SHRP2 created a suite 

of tools to correctly identify, map, and 

manage utilities. This set of tools in

cludes three separate products, often 

referred to as the “utilities bundle” when 

combined, that can help State DOTs 

and other transportation agencies miti

gate potential negative effects related 

to utilities and transportation projects. 

Utility Investigation 

Technologies

The first SHRP2 utilities product, Utility 

Investigation Technologies (R01B) 

(previously called Utility Locating 

Technologies), consists of two geo

physical technologies that can help 

transportation agencies gather more 

detailed information about subsurface 

conditions, position, and depth of 

utilities. SHRP2 research and imple

mentation partners identified the MultiChannel Ground Penetrating Radar 

(MCGPR) technology first, but users 

found it did not perform well in clayrich soils. SHRP2 partners then intro

duced Time Domain Electromagnetic 

Induction (TDEMI) as an alternative 

technology. TDEMI works in any geo

logic setting, but it cannot detect nonmetallic utilities without a tracer wire.

Six State DOTs (Arkansas, California, 

Indiana, Montana, Ohio, and Oregon) 

tested the R01B product technologies 

as part of the SHRP2 IAP. The IAP 

States generally found the benefits to 

be worth the effort. Most IAP States 

identified the technologies as a costeffective way to augment the subsurface 

utility engineering (SUE) process of 

locating utilities. State DOTs reported 

saving time, increasing accuracy, and 

improving the overall success rates 

of defining utilities during the design 

phase of a transportation project. 

“Historically, one of our largest 

sources of construction cost overruns 

and time delays has been utility con

flicts,” says Christopher Pucci, project 

surveyor with the Oregon Department 

of Transportation (ODOT). “[We got 

involved in R01B with] the hope that 

spending some money upfront doing a 

more thorough utility investigation could 

save a lot of money in construction. 

[After using these technologies,] we can’t 

continue the way we had been going, 

knowing what we know now. We can 

get better utility locations, we can avoid 

a majority of utility conflicts through 

more informed design, and we can save 

time and money in construction.”

ODOT also identified some lessons 

learned when working with R01B. In its 

10 • PUBLIC ROADS • AUTUMN • 2019
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final report, ODOT stated that the tech

nology is complicated and requires “con

siderable time and skill to process and 

evaluate” the data, integrate the existing 

SUE information, and evaluate the com

bined results into a 3D model. ODOT 

also pointed out the importance of 

knowing whether the project requires 3D 

deliverables or 2D deliverables because 

the cost difference may be significant.

A contractor uses a pipe and cable locator to mark 

underground utilities.

© ODOT.

Identifying and Managing 

Utility Conflicts

The second product in the utilities 

bundle, Identifying and Managing Utility 

Conflicts (R15B), includes several tools 

transportation agencies can incorporate 

into existing business practices to iden

tify and resolve utility conflicts. These 

tools include a stand-alone template 

for utility conflict lists, a utility conflict 

data model and database, and a 1-day 

utility conflict management training 

course. Eighteen State DOTs partici

pated in the IAP for R15B. Participating 

States included California, Delaware, 

Indiana, Iowa, Kentucky, Maryland, 

Michigan, Montana, New Hampshire, 

Oklahoma, Oregon, Pennsylvania, 

South Carolina, South Dakota, Texas, 

Utah, Vermont, and Washington.

The benefits of R15B include time 

savings through earlier identification and 

solutions, more effective management 

of conflicts through the project develop

ment and delivery process, fewer contractor change orders and delay claims, 

a reduction of costs stemming from 

delays, better communication between 

transportation agencies and utilities, a 

reduced impact on the traveling public, 

and improved safety for workers.

“We realized significant improvements 

in our utility accommodations process as 

a result of the SHRP2 R15B product,” 

says Charon Williams, director of the 

utility portfolio at the Texas Department 

of Transportation (TxDOT) Right 

of Way Division. “We experienced 

estimated savings of $10 million and 

about 38 months on our five pilot 

projects. So, we are definitely encouraged 

by the results. We are planning statewide 

implementation of R15B in the fall.”

States interested in implementing 

R15B should begin with the lessons 

learned from other State DOTs. One 

lesson is that standardization of util

ity conflict management is critical, as 

consultants, contractors, and utility 

owners frequently operate across dis

trict boundaries. In addition, TxDOT 

found that the 1-day utility conflict 

management training course was im

portant in obtaining buy-in from 

stakeholders for the R15B product.

This diagram demonstrates the life cycle of utility data management at a State DOT. The SHRP2 3D Utility Location 

Data Repository (R01A) is a state-of-the-art 3D storage and retrieval data model.

© Texas A&M Transportation Institute.

3D Utility Location 

Data Repository

Lastly, the 3D Utility Location Data 

Repository (R01A) is a state-of-the-art 

3D storage and retrieval data model 

that provides the horizontal and verti

cal location of the facility as well as the 

type of utility. The product provides 

benefits in the design, field data collec

tion, and construction areas of trans

portation projects. Designers may alter 

their designs to accommodate extensive 

utility locations, which saves money by 

avoiding costly utility moves. Collecting 

data in a single operation also cuts 

costs. Eleven State DOTs took advan

tage of the SHRP2 IAP for R01A.

“Having a centralized, enterprise-level 

utility data repository offers significant 

advantages and potential compared to 

the stand-alone concept that existed 

prior to the R01A implementation,” says 

Donna Fanelli Rodrick, transportation 

surveyor with the California Department 

of Transportation (Caltrans), which 

used all three SHRP2 utility products. 

“We plan to use the utility database 

to store, retrieve, and update data and 

make it part of the utility verification 

process we use on each project.”

Caltrans and other IAP State partici

pants agreed that the most important 

lesson they took away from implemen

tation is to obtain and maintain buy-in 

from the agency’s administration, as lead

ership is often unaware of the impor

tance of managing utility data effectively. 

The State DOTs also suggested first 

pursuing a relatively simple utility data 

repository approach, focusing on “lowhanging fruit” while learning the process. 

As SHRP2 wound down during 

summer 2019, many IAP States planned 

to continue the work they began during 

the program by carrying these utility 

products forward. 

“We have revised our schematic contracts to include utility coordination and 

conflict identification in the preliminary 

phases of design,” says Anna Pulido, 

utility manager with TxDOT. “This is 

just the beginning of many more things 

to come.”

Maggie Kasperski is the communica

tions and marketing manager with the 

American Association of State Highway 

and Transportation Officials. She holds 

a bachelor’s degree in public relations 

from the State University of New York 

at Fredonia, and two master’s degrees 

(in public relations and international 

relations) from Syracuse University. 

For more information, see http 

://shrp2.transportation.org/Pages 

/UtilityRelatedProducts.aspx or contact 

Julie Johnston, utilities and value 

engineering program manager with 

FHWA, at julie.johnston@dot.gov.

PUBLIC ROADS • AUTUMN • 2019 • 11
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12 • PUBLIC ROADS • AUTUMN • 2019

The Pulaski Skyway deck replacement in New Jersey 

is the largest use of ultra-high performance concrete 

(UHPC) on a single project. UHPC is one of 11 

innovations FHWA promoted in EDC-4.

© WSP USA.

Are You an 

Innovation Champion?

State and local agencies embrace new norms throughout the fourth round of Every Day Counts.

by Julie Zirlin

Transportation agencies find 

effective ways to deliver programs and projects that meet 

the public’s need for safe and efficient 

travel through the Federal Highway 

Administration’s Every Day Counts 

(EDC) program. EDC is a State-based 

model that promotes rapid deployment 

of proven but underutilized innova

tions to shorten the project delivery 

process, enhance roadway safety, reduce 

traffic congestion, or integrate automa

tion. During the fourth round of EDC 

(EDC-4), which began in 2017, States 

selected from 11 promoted innovations 

to best meet their needs and established 

2-year goals to demonstrate, assess, or 

institutionalize the innovations.

EDC-4 deployment had a significant 

positive impact on the adoption of new 

technologies and practices within the 

transportation community. Technical 

assistance provided by teams of experts 

and incentives offered through the 

State Transportation Innovation 

Council (STIC) incentive programs and 

Accelerated Innovation Deployment 

(AID) Demonstration grants helped 

States reach their goals. Six of the 

EDC-4 innovations are now in use in 

more than 40 States.

“Every Day Counts inspires State and 

local governments to adopt cutting-edge 

technologies and practices in their ongo

ing quest to save lives, shorten project de

livery, and minimize cost to the taxpayer,” 

says Nicole Nason, FHWA administrator.

What follows are highlights of five 

successfully deployed EDC-4 innovations. 

Strengthening Bridges

The nationwide growth of using ultrahigh performance concrete (UHPC) to 

connect prefabricated bridge elements 

and systems (PBES) illustrates the ef

fectiveness of EDC’s rapid deployment 

process. UHPC is a steel fiber-reinforced, 

portland cement-based material that de

livers performance far exceeding that of 

conventional concrete. Built offsite and 

moved to the project location for instal

lation, prefabricated bridge elements 

(PBEs) shorten onsite construction time, 

enhance safety, and offer superior durabil

ity. Field-cast UHPC creates connections 

between PBEs that use less concrete and 

provide better long-term performance 

than typical connections.

The EDC Deployment team set a goal 

for at least 30 transportation agencies to 

use UHPC on a minimum of 100 highway bridges in the country. As of January 

2019, approximately 31 agencies have 

used UHPC on 203 bridges. In addition 

to construction projects, transportation 

agencies have developed standards and 

guidelines for using UHPC, and more 

than 18 agencies have or are currently 

conducting their own research on UHPC 

materials or applications. 

In 2018, the New Jersey Department 

of Transportation (NJDOT) completed 

the 3.5-mile (5.6-kilometer)-long Pulaski 

Skyway deck replacement. This project 

is currently the largest to use UHPC 

in North America, using more than 

5,000 cubic yards (3,800 cubic meters) 

of UHPC to connect nearly 1 million 

square feet (93,000 square meters) of 

deck panels. The State selected UHPC in 

conjunction with PBEs, in part, because 

it provides a durable deck with the lon

gest service life and least maintenance. 

In addition, the elimination of cast-inplace concrete for the bridge simplified 

the onsite operations for the project. 

The skyway has served as an important 
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and informative example for other agen

cies since selection of UHPC for the 

project in 2012.

NJDOT completed five other bridges 

with UHPC in 2018, bringing the State’s 

total to nine bridges using UHPC. 

Taken at the Eel River in Indiana, this two-dimensional 

hydraulic modeling graphic depicts the hydraulic 

conditions at a bridge crossing, including a more 

accurate depiction of flow splits, flow velocity 

magnitude, and direction. 

© Indiana Department of Transportation; 

Aerial image © Earthstar Graphics. 

Improving Traffic 

Signal Operations 

How well the Nation’s 330,000-plus traf

fic signals perform used to be a difficult 

question to quantify. Now, transportation 

agencies in more than 30 States have 

access to automated traffic signal perfor

mance measures (ATSPMs), a suite of 

performance measures, data collection 

tools, and analysis tools.

ATSPMs transform signal mainte

nance and operations from reactive to 

proactive. While citizen complaints are 

typically the primary performance mea

sure for most signals, ATSPMs provide 

the information needed to manage traf

fic signal maintenance and operations in 

a data-driven and cost-effective way. The 

cost to retime signals is approximately 

$4,500 per intersection, and typically 

agencies do this on a 3- to 5-year cycle. 

During EDC-4, States implemented 

ATSPMs to improve traditional retiming 

processes by providing continuous per

formance monitoring capability. By the 

end of EDC-4, 31 States had attained 

demonstration, assessment, or institu

tionalized stages of implementation. 

The Colorado Department of 

Transportation (CDOT) implemented 

ATSPMs on about 50 traffic signals on 

6 arterial corridors in the Denver area. 

CDOT is updating infrastructure at 100 

additional signal locations to collect and 

analyze high-resolution data logs from 

signal controllers and to generate reports 

to evaluate the benefits.

CDOT reports improved response 

times and cost savings from proactively 

addressing signal operation and mainte

nance issues. Public complaints on sig

nals in optimized corridors decreased by 

as much as 30 percent.

Encouraging Next Generation

Hydraulic Engineering

Hydraulic modeling tools used for 

nearly 60 years apply assumptions that 

can lead to overly conservative, inad

equate, or inaccurate project designs. 

The Collaborative Hydraulics: Advancing 

to the Next Generation of Engineering 

(CHANGE) initiative encourages States 

to shift from the use of one-dimensional 

modeling to implementing two-dimen

sional (2D) modeling and graphical visu

alization tools. 

These 2D tools enable users to create 

better representations of the often com

plex interaction between transportation 

assets and river or coastal environments. 

These representations provide planning 

and design teams with better data to 

improve project quality. Ultimately, the 

results of these techniques enable more 

INNOVATION DEPLOYMENT 

ASSISTANCE

FHWA offers assistance and resources 

to help States and their partners deploy 

the innovations in the Every Day 

Counts program.

FHWA assembles deployment teams 

for each EDC innovation to provide 

the transportation community with 

information, technical assistance, and 

training, including workshops and peer 

exchanges. Visit www.fhwa.dot.gov 

/innovation/everydaycounts/contacts.cfm for 

a list of experts to call for assistance on 

innovations in current and past rounds 

of EDC. For more details on the EDC 

program, contact Julie Zirlin, program 

coordinator for the FHWA Center for 

Accelerating Innovation (CAI), at 

julie.zirlin@dot.gov.

AID Demonstration program 

This program awards funding up to 

$1 million for projects that use proven 

innovations in any project phase. 

Visit www.fhwa.dot.gov/innovation/grants 

/projects for an overview of 92 

projects that received more than 

$66 million in AID Demonstration 

grants. For more details on the AID 

Demonstration program, contact Fawn 

Thompson, CAI program coordinator, 

at fawn.thompson@dot.gov.

STIC Incentive Program The 

STIC program provides up to $100,000 

a year per State to help STICs make 

innovations standard practices. Visit 

www.fhwa.dot.gov/innovation/stic 

/incentive_project for examples of how 

STICs are using incentive funds. For 

information on the STIC Incentive 

program, contact Sara Lowry, CAI 

program coordinator, at sara.lowry 

@dot.gov.

Another option is the use of an 

increased Federal share of up to 5 

percent for projects that use new 

innovative project delivery methods. 

This option incentivizes the use of 

innovation to help deliver projects 

more efficiently and deploy proven 

solutions that make a difference. 

For more information, visit www.fhwa 

.dot.gov/innovation/resources/increased 

_federal_share.cfm or contact Sara 

Lowry, CAI program coordinator, 

at sara.lowry@dot.gov.

PUBLIC ROADS • AUTUMN • 2019 • 13
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accuracy in estimating flow conditions 

and paths, evaluating hydraulic consider

ations, and assessing extreme events and 

evaluating resilience.

By the end of EDC-4, 9 States had 

institutionalized the use of collaborative 

hydraulics, and another 34 were demon

strating and assessing the innovation. 

CDOT successfully used 2D modeling 

to design repairs to river channel bank 

revetment around bridges that protect 

bridge foundations after a flood in 2013. 

Use of the 2D modeling analysis saved 

CDOT more than $9 million in con

struction costs on the project along the 

Big Thompson River between Loveland 

and Estes Park, CO. Overall, CDOT has 

documented $13.5 million in construction 

material savings by applying these meth

ods to reduce risk and uncertainty.

The MSAR app helped the Texas Department of 

Transportation obtain approval for Federal recovery 

funds faster after Hurricane Harvey.

Source: FHWA.

Going Paperless

In e-Construction and Partnering: A 

Vision for the Future, States use paperless technologies to enhance partnership 

among stakeholders on construction 

projects, improving communication 

and workflows while streamlining 

project delivery.

e-Construction is the digital creation, 

review, approval, distribution, and stor

age of highway construction documents. 

It uses readily available technology to 

improve construction document manage

ment, saves time by decreasing delays 

seen in paper-based project administra

tion, and creates a collaborative environ

ment between transportation agencies, 

contractors, and other stakeholders. 

Return on investment for construction 

management, project collaboration, mobile devices, and electronic bidding tools 

using e-Construction, ranges from 200 

to more than 700 percent. The use of 

e-Construction and Partnering creates 

a collaborative environment that im

proves efficiency in project management 

and delivery. 

By the end of EDC-4, 15 States insti

tutionalized the use of e-Construction 

and Partnering, and another 31 were 

demonstrating and assessing 

e-Construction. 

The Florida Department of Transpor

tation (FDOT) has used e-Construction 

for all construction contracts since July 

2016. FDOT provides its field staff with 

mobile devices for use in the paperless 

process, which enables instantaneous data 

collection and the ability to troubleshoot 

and resolve issues in the field. The agency 

estimates e-Construction saves $22 million per year.

Recently, FHWA showcased the ben

efits of e-Construction with the use of 

the Mobile Solution for Assessment and 

Reporting (MSAR) application, which 

played a key role in recent disaster recov

ery. This app replaced paper-based sur

veys and inspection reports on disaster 

damage required for FHWA’s Emergency 

Relief program.

When the Texas Department of 

Transportation (TxDOT) used the app 

after Hurricane Harvey in 2017, more 

than 500 sites were approved for Federal 

recovery funds within 7 months instead 

of up to 2 years using a paper-based 

process. Reducing clerical work and time 

needed to create reports saved TxDOT 

about $1.3 million.

STEP-ping Up Safety

Pedestrians account for more than 16 

percent of all traffic fatalities and more 

than 72 percent of pedestrian fatalities 

occur at nonintersection locations such 

as midblock areas. Safe transportation 

for every pedestrian (STEP) features 

proven, cost-effective countermeasures 

that can reduce pedestrian fatalities at 

uncontrolled crossing locations and un

signalized intersections. 

In EDC-4, FHWA encouraged 

States to incorporate one or more 

of the six safety countermeasures in

cluded in STEP to enhance pedestrian 

safety. STEP includes crosswalk vis

ibility enhancements, raised crosswalks, 

pedestrian refuge islands, pedestrian 

hybrid beacons (PHBs), road diets, and 

rectangular rapid flashing beacons.

14 • PUBLIC ROADS • AUTUMN • 2019
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Crosswalk visibility enhancements such as high-visibility markings and in-street signs help make crosswalks and 

pedestrians more visible.

Source: FHWA.

By the end of EDC-4, 42 States 

had attained demonstration, assess

ment, or institutionalized stages 

of implementation. 

The Hillsborough County Metro

politan Planning Organization identified 

Hillsborough Avenue in Tampa, FL, 

as a high-crash and high-use corridor. 

FDOT installed PHBs to control traffic 

at midblock crossings and unsignalized 

intersections. In addition to the beacons, 

FDOT upgraded roadway lighting along 

the corridor and installed pedestrian 

actuated lighting to illuminate crosswalks 

when someone presses the pushbut

ton for the PHB. In the year follow

ing the upgrades, Hillsborough Avenue 

saw a decrease in bicycle and pedestrian 

crashes—7 compared to the previous 

6-year average of 20.

Building on Success

The fifth round of Every Day Counts 

(EDC-5) promotes a set of 10 inno

vations being deployed by State agen

cies and their partners from 2019 

through 2020.

In addition to FHWA’s ongoing part

nerships and assistance through EDC, 

the national STIC Network is leveraging 

the expertise of stakeholders throughout 

the country to foster an ongoing culture 

of innovation in the transportation com

munity. STICs in each State are made 

up of public and private transportation 

stakeholders who evaluate innovations 

and champion deployment efforts. 

Working through the STICs, State de

partments of transportation can consider innovations promoted by EDC and 

by others. 

“The growing culture of innovation 

across the country is helping agencies 

deliver projects faster, more efficiently, 

and in a way that delivers cost savings 

to the taxpayer,” says Thomas Harman, 

director of the FHWA Center for 

Accelerating Innovation. “Innovation 

champions nationwide are improving the 

safety and efficiency of our transporta

tion system.”

Julie Zirlin is the program manager 

for the Every Day Counts program 

with the FHWA Center for Accelerating 

Innovation. 

For more information, see Every Day 

Counts: An Innovation Partnership With 

States—EDC-4 Final Report (FHWA19-CAI-013) at www.fhwa.dot.gov 

/innovation/everydaycounts/reports 

/edc4_final. Or contact Julie Zirlin 

at julie.zirlin@dot.gov or 202–366–9105. 

INNOVATIONS FEATURED 

IN EDC-4

Automated Traffic Signal 

Performance Measures

Collaborative Hydraulics: 

Advancing to the Next Generation 

of Engineering (CHANGE)

Community Connections

Data-Driven Safety Analysis

e-Construction and Partnering: 

A Vision for the Future

Integrating National Environmental 

Policy Act (NEPA) and Permitting

Pavement Preservation 

(When, Where, and How)

Road Weather Management – 

Weather Savvy Roads

Safe Transportation for Every 

Pedestrian (STEP)

Ultra-High Performance Concrete 

Connections for PBES

Using Data to Improve Traffic 

Incident Management

PUBLIC ROADS • AUTUMN • 2019 • 15
The United States and the Republic of Korea 

have much to offer each other during personnel 

exchanges that include annual workshops and site 

visits.

© Starcevic, Getty Images.

Learning from 

International Perspectives 

The United States and the Republic of Korea have a long-standing 

program to exchange transportation knowledge and ideas. 

by Jihan Noizet

Technology is evolving rapidly in the highway transportation 

industry. One way to help keep pace is for transportation 

agencies to share knowledge and successes—even between 

countries.

The Binational Relations Programs team of the Federal 

Highway Administration’s Office of International Programs 

facilitates and coordinates exchanging knowledge with 

transportation professionals around the globe. Governmentto-government relations between FHWA and the Republic 

of Korea’s Ministry of Land, Infrastructure, and Transport 

(MOLIT) are one such arrangement that has provided tangible 

and intangible benefits over the span of more than 2 decades.

Beginning with an agreement signed in 1995, the Federal 

road agencies of the United States and the Republic of 

Korea have exchanged innovative and time-tested ideas for 

improving roadway-related infrastructure, highway design 

concepts, planning techniques, construction procedures, 

roadway safety, and traffic operations. The program relies 

on workshops, site visits, and personnel exchanges to 

enable each nation’s technical staff to share their knowledge 

and improve their country’s transportation practices.

Workshops

Annual workshops are the cornerstone of the program 

with the Republic of Korea. During these multiday 

events, technical experts and leaders from both agencies 

present best practices and share the latest technological 

innovations. The two countries alternate hosting 

responsibilities, creating an opportunity for professionals 

to experience each country’s highway system in person. 

“Various aspects of a country, such as its culture, the 

mindset of the people, its natural environment, and economic 

situation are reflected in the roads of that country,” says Jiwon 

Oh, a visiting research engineer from the Republic of Korea.

Workshop presentations have covered a wide range 

of highway transportation topic areas, including policy, 

planning, standards, funding and financing, data analysis 

tools and methods, infrastructure design, operations, safety, 

construction and materials, maintenance, asset management, 

sustainability and resilience, and information technology 

services. Each presentation brings a unique perspective 

and inventory of knowledge that benefits the attendees. 

Workshop participants discuss new possibilities and challenges, 

brainstorm solutions and improvements, and return home 

with new ideas, methods, and concepts to further explore in 

the context of their home country’s highway system needs.

For example, during the 2015 workshop in Washington, 

DC, the attendees from the United States learned about 

MOLIT’s automated bridge inspection technology, which is 

used on the Republic of Korea’s expressway structures. The 

automated system provides safe and convenient working 

conditions, makes inspections faster and more efficient, 

ensures objectivity and reliability, and builds an integrated 

scientific database. The system uses a remote control 

16 • PUBLIC ROADS • AUTUMN • 2019
system called the Ubiquitous Bridge 

Inspection Robot System (U-BIROS), 

which generates an inspection report. 

Representatives from FHWA and MOLIT attend a 

presentation and discussion during one of the annual 

workshops. 

Source: FHWA.

Site Visits

Site visits are an essential element of 

the annual workshop, and previous 

participants identified them as the 

most practical and impactful activity. 

Through the program, participants have 

explored more than 30 engineering 

projects in both countries.

In 2016, the Korean Expressway 

Corporation organized a trip to an 

expressway where the attendees observed 

rockfall and land stabilization measures. 

The stabilization system is unique to 

the Republic of Korea, and the visit 

provided an important opportunity for 

U.S. participants to study the distinctive 

approach. The design of the reinforced 

concrete for the anchoring system could 

provide several advantages over the 

traditional reinforced concrete block 

used in the United States. U.S. engineers 

and transportation professionals took the 

knowledge home to investigate further.

Past site visits have offered handson information about infrastructure 

inspection and management, bridge 

engineering, roadway design, traffic 

operations and safety, and construction 

engineering. The experience of seeing 

onsite demonstrations, new technologies, 

and prototypes in person stimulates 

discussion on how to implement 

and improve each country’s highway 

transportation system. The face-to-face 

collaboration enables participants to 

more effectively address the nuanced 

complexity of issues faced by both 

agencies.

Personnel Exchanges

Extended interaction between 

participants of both agencies and 

exposure to each other’s working 

environments enables personnel to 

share indepth information about 

highway system-related strengths, 

challenges, and processes. During 

a personnel exchange, employees 

from FHWA and MOLIT undertake 

extended assignments in their 

counterpart’s transportation agency, 

fully immersed in the agency’s culture. 

While an FHWA employee has 

spent time at MOLIT, the exchanges 

have primarily involved MOLIT 

representatives working in the United 

States for 18 to 24 months. These 

exchanges bring in experts with new 

and fresh perspectives, enabling both 

parties to expand their knowledge 

base by sharing experiences and 

collaborating on solutions.

For example, through the exchanges, 

FHWA has gained information 

on construction engineering and 

steel prefabricated construction 

and systems—areas where MOLIT 

has extensive expertise. An FHWA 

engineer visiting the Republic of Korea 

also learned about MOLIT’s bridge 

maintenance and preservation program.

In addition, time spent immersed 

in the transportation culture of 

another country helps both parties 

identify knowledge gaps in their 

respective programs. One example 

is the advanced connected vehicle 

programs of the United States and 

the Republic of Korea. The exchange 

engineer can provide insights and 

coordinate activities between the two 

agencies that support the development 

of global connected and autonomous 

vehicle interoperability standards. 

Engineers involved in these extended 

personnel exchanges return home with 

the ability to benchmark the capabilities 

of their transportation systems against 

those they visited. Doing so reveals 

areas where improvements are possible 

and where leveraging the knowledge 

of another transportation organization 

can assist in the improvements. 

“Transportation challenges are similar 

around the world,” says Randy Iwasaki, 

the executive director of the Contra 

Costa Transportation Authority and 

formerly the chief deputy director at the 

California Department of Transportation, 

who participated in the program under 

the auspices of FHWA as a subject 

matter expert providing a State DOT 

perspective. “This program provides 

a great opportunity to learn how our 

colleagues in the Republic of Korea are 

using innovative transportation methods 

and solutions that we can also apply to 

improve the life of our infrastructure.”

Program Benefits

Although technology has made a 

constantly changing world more 

connected than ever before, the 

ability to question, collaborate, and 

troubleshoot in person is invaluable. 

Workshops, site visits, and personnel 

exchanges enable both countries to 

collaborate, share, and grow their 

technical knowledge by providing a 

platform with a variety of benefits.

Benchmark Transportation 

Practices and Technologies

Through the program, the agencies 

can benchmark advances in every 

aspect of transportation engineering 

and infrastructure and collect ideas 

for how to improve transportation 

practices in their home countries. 

PUBLIC ROADS • AUTUMN • 2019 • 17
LEFT: Workshop participants attend a site visit in 

Chicago in 2001.

Source: USDOT.

ABOVE: Site visits, like this one in Seoul in 2002, 

are a key component of the information exchanges 

between the United States and the Republic of Korea. 

Participants highly value these onsite experiences. 

Source: USDOT.

Collaborate Face-To-Face

In-person collaboration enables 

participants to discuss technical 

hurdles, describe complex issues, 

and convey field-tested solutions to 

roadway and infrastructure challenges.

Provide In-Person 

Technical Assistance 

Site visits enable participants to 

observe each country’s state-ofthe-art practices firsthand and ask 

technical questions that would be 

difficult to communicate remotely.

Learn Hands-On 

Through Site Visits 

These in-the-field knowledge 

exchanges, which are not possible 

remotely, provide valuable insight 

that can only be gained through 

hands-on experience. During one 

visit, FHWA personnel observed 

MOLIT’s next generation of 

transportation management centers 

and how the agency handles the 

growing congestion challenge 

in its capital city, Seoul.

Immerse Engineers in Another 

Country’s Technical Environment 

Engineers from other countries 

approach problems differently. The 

exchange program enables transportation 

professionals from both countries to 

brainstorm new solutions for tackling 

problems together. Full immersion 

ensures exchange engineers are 

integrated into the hosting agency, 

enabling their unique perspectives and 

innovative ideas to have the most impact.

For example, during one residency 

in FHWA’s Office of Safety, a MOLIT 

engineer learned about FHWA’s proven 

safety countermeasures—roundabouts 

and high-friction pavement treatments 

in particular. MOLIT plans to use this 

information to broaden and improve 

the use of these countermeasures 

in the Republic of Korea.

Each element of the program offers 

unique benefits. Workshops create a 

designated time and space for the two 

countries to exchange knowledge on 

a multitude of highway transportation 

topics. Site visits offer hands-on 

opportunities for participants to learn 

about the highway features unique to 

the systems in the United States and the 

Republic of Korea. Personnel exchanges 

provide the benefit of learning through 

cultural immersion and extended 

experience in the processes and systems 

of the host nation. 

“This combination of activities 

enables the program to be broad 

enough to capture a wide array of 

transportation specialties but specific 

enough to enable engineers to dig into 

the weeds and tackle challenging 

technical issues across country 

lines,” says Alfred Logie of FHWA’s 

Office of International Programs.

Collaborating for 

Continued Success

The knowledge exchange program 

between FHWA and MOLIT has 

created a collaborative, symbiotic 

environment that benefits the 

transportation infrastructure and 

practices of both countries. These 

formal interactions have led to better 

highway transportation systems, 

stronger ties, informal exchanges, 

and greater collaboration between 

transportation professionals 

in both countries.

Myint Lwin, former FHWA 

director of bridge technology, says, 

“Learning and sharing globally will 

lead to integration of best practices in 

assuring safety to the traveling public 

and good stewardship of public funds.”

Jihan Noizet is a transportation 

specialist in FHWA’s Office of 

International Programs and oversees 

the coordination and implementation of 

cooperative program activities between 

FHWA and its foreign counterparts. She 

holds a bachelor’s degree in business 

administration from the University of 

North Texas, and a master’s degree 

in business administration from the 

University of Texas at Dallas. 

For more information, contact 

Jihan Noizet at jihan.noizet@dot.gov or 

206–366–1153, or download the Synthesis 

Report of the FHWA and the MOLIT 

Knowledge Exchange Since 1995 (FHWAPL-18-041) at https://international.fhwa 

.dot.gov/links/pubs.cfm.

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SPEEDING UP

Bridge Deck Evaluations

by Hoda Azari and Mehdi Rashidi

FHWA researchers 

developed a robotic aircoupled acoustic system 

to reduce traffic delays 

and increase safety when 

collecting data to assess 

condition.

FHWA developed this robotic air-coupled acoustic 

NDE system to speed and improve inspection of 

bridge decks.

Source: FHWA.

I

nspecting and managing more than 

600,000 bridges in the Nation’s in

ventory with limited resources is 

challenging for bridge owners. The chal

lenge is further complicated by the fact 

that the average age of these bridges is 

more than 40 years. More specifically, 

bridge decks require the most frequent 

maintenance and preservation because, 

on average, they deteriorate faster than 

all other bridge components. This is 

because of the routine application of 

deicing salts and sustained traffic load 

in addition to environmental effects.

Recently, bridge owners across the 

country worked toward implementing asset management plans and performancebased management to maintain, preserve, 

and improve the highway system. An 

essential component of this approach is 

to have reliable and quantitative informa

tion regarding the physical condition of 

structures and a greater understanding 

of their deterioration processes. The 

use of nondestructive evaluation (NDE) 

technologies is complementary to the 

current state of the practice for assess

ing the condition of structures, which is 

based on visual inspection and manual 

sounding techniques.

Over the past decade, bridge own

ers increasingly have used NDE tech

nologies as an assessment tool in bridge 

inspection because they (1) enable 

periodic assessment of 

PUBLIC ROADS • AUTUMN • 2019 • 19
20 • PUBLIC ROADS • AUTUMN • 2019

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structures without causing damage and 

compromising their structural integrity, 

and (2) provide information about de

fects invisible to the naked eye. 

The Federal Highway Administration 

is researching and developing NDE 

technologies as a solution to myriad 

challenges, including a means by which 

to use a noncontact (or air-coupled) 

acoustic array to evaluate bridge decks. 

The contactless technology, when compared to contact sensors, significantly 

speeds assessment times, reducing lane 

closure times and increasing safety for 

inspectors and highway travelers. 

An air-coupled transducer (source) and an array 

of microelectromechanical system microphones 

(receiver) hover above a section of concrete slab.

Source: FHWA.

CONTACT-BASED 

ACOUSTIC TECHNIQUES

Acoustic techniques including impact 

echo and ultrasonic surface waves, which 

are based on mechanical wave propa

gation, provide information about the 

geometry (for example, thickness) and 

mechanical properties (for example, 

elastic modulus) of a medium. Acoustic 

techniques are effective in detecting 

internal defects such as delamination, 

voids, and cracks within a structure. 

Because mechanical vibration generates 

different particle motions in different 

solid media, mechanical wave propaga

tion velocity and amplitude are related 

directly to the elastic constants of the 

material. Internal cracks, voids, delami

nation, and other internal defects cause 

variations in the measured wave.

Bridge inspectors perform contactbased acoustic methods using a source 

to generate the acoustic signal and one 

or more receivers for capturing the re

sponse. The inspectors apply a couplant 

at the contact surface between acoustic 

probes and the structure to ensure the 

proper transmission of acoustic waves 

to the testing medium. However, this 

approach limits the detection of internal 

defects in highway structures. Depending 

on the size of the structure being tested 

and the desired spatial resolution of test 

results, the scan of the structure may require thousands of measurement points. 

Furthermore, if the concrete surface has 

a rough texture, it may restrict effective 

mechanical coupling between contact 

sensors and the test surface, which can 

make the repeatability of measurements 

challenging. Overall, the process of 

pressing the sensors against the surface 

at each measurement point, detaching 

the sensors, moving them to the next 

measurement point, and ensuring adequate coupling with the surface is timeconsuming and costly.

Contact-based acoustic techniques 

increase the duration of lane closures 

and risk to workers and drivers. Besides 

safety, the longer assessment period 

required for contact-based acoustic tech

niques takes a toll on the U.S. economy 

and environment by contributing to 

traffic congestion. In 2014, U.S. highway 

travelers wasted 6.9 billion hours and 3.1 

billion gallons (11.7 billion liters) of fuel 

because of traffic delays. That resulted in 

an overall estimated cost of $160 billion. 

“Along with safety concerns, the 

negative impact on resources and the 

staggering related costs of traffic con

gestion are motivating factors for using 

technologies to speed inspections of 

highway structures,” says Jean Nehme, 

Ph.D., team leader of FHWA’s LongTerm Infrastructure Performance programs. “Therefore, any practice that can 

promote the safety of road users and 

bridge inspectors, while reducing traffic 

congestion by minimizing the duration of 

work zones and lane closures, would be 

a significant improvement to the current 

state of the practice.”

A HIGH-SPEED SOLUTION

An effective solution to the time-consum

ing inspection process using conventional 

acoustic techniques is to eliminate the 

need for physical contact between the 

sensors and a structure. Researchers at 

FHWA’s Advanced Sensing Technology 

(FAST) NDE Laboratory used a contactless acoustic source and receivers to de

velop an air-coupled (that is, no contact) 

acoustic array to evaluate bridge decks. 

The fully air-coupled system mounts on 

a robotic platform for high-speed evalua

tion of bridge decks.

In this air-coupled system, a signal 

generates through a waveform generator and feeds into an amplifier, which in 

turn sends the signal to an air-coupled 

transducer to excite the structure through 

the air medium. Microelectromechanical 

system (MEMS) microphones capture the 

response of the structure as the propa

gating wave leaks from the structure to 

the air. The resulting measurements are 

highly reliable and repeatable because 

the air-coupled system does not have 

the variability of the contact between 

the sensors and the structure, which is a 

major issue during conventional acoustic 

measurements.

The small size of the MEMS microphones (approximately 5 millimeters), 
PUBLIC ROADS • AUTUMN • 2019 • 21

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their high sensitivity, and their low cost 

(typically less than $1) enables a custom

izable array of microphones capable of 

high-resolution scanning of bridge decks 

at a low cost. To minimize the noise to 

improve the accuracy of the measure

ments, researchers at FHWA’s NDE lab 

implemented a proper shielding of the 

source from the receiver. Like conven

tional acoustic techniques, the received 

signal on a delaminated section has 

different characteristics than that on an 

intact area.

By adjusting the angle of the acoustic 

source with respect to the surface of 

the structure, the air-coupled system can 

generate both body and surface waves. 

The body waves generally can detect 

shallow and deep flaws, but their ampli

tude significantly decreases because of 

the strong interaction with the medium. 

For example, body waves are highly 

damped in reinforced concrete because 

of its heterogeneity. On the other hand, 

surface waves typically are sensitive to 

shallow flaws, but their loss of amplitude 

is less significant than body waves, and 

they travel a longer distance in a me

dium than body waves can. Most of the 

surface wave energy is contained within 

a thickness zone of approximately one 

wavelength below the surface, which 

researchers often refer to as the wave 

penetration depth. The surface waves’ 

depth of penetration in the structure 

can be adjusted by controlling the wave 

center frequency. Overall, the air-coupled 

system can estimate the concrete modu

lus through analyzing the surface waves 

and estimate the depth and size of flaws 

in bridge decks through the analysis of 

body waves.

This graph shows the numerical simulation of 

propagating leaky wave between air and concrete. 

The amplitude of leaky waves is significantly lower 

compared to other waves. 

Source: FHWA.

ROBOTIC ASSISTANCE 

INCREASES EFFECTIVENESS

The bridge community is increasingly 

using robotic platforms for the NDE 

of highway structures. Under the LongTerm Bridge Performance (LTBP) 

Program, FHWA funded a research 

project to develop a Robotic Assisted 

Bridge Inspection Tool (RABITTM). The 

RABIT, which is now commercialized, 

measures electrical, electromagnetic, and 

acoustic properties of reinforced con

crete structures to estimate the state of 

damage. 

The process of data collection using 

RABIT is faster and less labor intensive 

than collecting data in a manual fashion. 

However, RABIT uses contact sensors 

for measuring the acoustic properties 

of the medium, so the condition assess

ment of bridge decks is still a timeconsuming task. Given the large number 

of measurement points required to scan 

a bridge deck, implementation of the 

air-coupled technologies on the RABIT 

can generate scans with a higher spatial 

resolution for bridge evaluation, save 

hours, and reduce the economical and 

environmental impacts of traffic conges

tion from lane closures. 

“With promising preliminary results 

from the air-coupled system, we hope 

for fast and reliable field measurements 

in the near future,” says Nehme. “The 

potential combination of the RABIT 

and the air-coupled acoustic system 

could present a huge step toward more 

efficient bridge deck inspections.” 

Hoda Azari is the manager of the 

NDE Research Program and Laboratory 

at FHWA’s Turner-Fairbank Highway 

Research Center. She holds a Ph.D. in 

civil engineering from the University of 

Texas at El Paso.

Mehdi Rashidi is a National Research 

Council research associate at FHWA’s 

Turner-Fairbank Highway Research 

Center. Rashidi is conducting research 

in NDE of highway structures. He 

holds a Ph.D. in civil engineering from 

Georgia Tech.

For more information, contact 

Hoda Azari at hoda.azari@dot.gov 

or 202–493–3064.

This circuit board contains four microelectromechanical system microphones and an amplifier. The 

system is not much larger than a quarter.

Source: FHWA.
22 • PUBLIC ROADS • AUTUMN • 2019

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ALONG THE ROAD

Along the Road is the place to look for information about current and upcoming activities, developments, trends, and items of 

general interest to the highway community. This information comes from U.S. Department of Transportation sources unless 

otherwise indicated. Your suggestions and input are welcome. Let’s meet along the road.

Public Information and 

Information Exchange

Federal Grants Help Modernize 911 Services

In August 2019, the U.S. Department of Transportation and 

the U.S. Department of Commerce announced more than 

$109 million in grants to 34 States and 2 Tribal nations as part 

of the 911 Grant Program. The grants will help 911 call 

centers upgrade to Next Generation 911 (NG911) capabilities.

The funding will power basic improvements such as 

providing digital and network capabilities to 911 emergency 

call centers and will assist implementation of advanced 

mapping systems that will make it easier to identify a 911 

caller’s location. NG911 will help 911 call centers manage call 

overload, as call takers will be able to transfer calls, messages, 

and data between interconnected, networked public safety 

answering points. The 911 Grant Program also provides 

funding for training costs directly related to NG911 

implementation.

The program made grants available to States, territories, 

Tribal nations, and the District of Columbia, provided that 

they successfully submitted a State 911 plan and project 

budget, designated a 911 coordinator, and certified that they 

did not use funds designated for 911 systems for other 

purposes in the past 180 days. The complete list of grant 

recipients is available at www.transportation.gov/briefing-room 

/departments-commerce-and-transportation-announce-109 

-million-grants-modernize-911.

The 911 Grant Program is jointly administered by the 

Department of Commerce’s National Telecommunications 

and Information Administration and the Department 

of Transportation’s National Highway Traffic Safety 

Administration. 

For more information, visit 911.gov and www.ntia.doc.gov 

/category/next-generation-911.

USDOT Selects Two New University 

Transportation Centers

USDOT recently announced $15 million in grants to two new 

national University Transportation Centers (UTCs) to advance 

research and education programs that address critical transpor

tation challenges facing the Nation. The University of South 

Florida and Washington State University will each receive 

$7.5 million.

“These investments in transportation research will help 

address our country’s congestion and durability challenges,” 

says U.S. Secretary of Transportation Elaine L. Chao.

USDOT received 51 competitive grant applications for the 

two new national UTCs. The centers will help develop answers 

to two key problems facing U.S. drivers: congestion and 

deteriorating infrastructure. The University of South Florida 

will focus on “Congestion Relief,” and Washington State 

University will focus on “Improving the Durability and 

Extending the Life of Transportation Infrastructure.”

UTCs advance U.S. technology and expertise in transporta

tion’s many modes and disciplines, and address workforce 

needs for the next generation of transportation leaders. 

For more information, visit www.transportation.gov/utc 

/fast-act-utc-grantees.

Colorado DOT Unveils Truck Safety Program for 

Mountainous Driving

The Colorado Department of Transportation (CDOT) 

recently launched a safety program geared toward truckers 

who travel over mountainous terrain. 

The Mountain Rules, launched in August 2019, is a safety 

initiative meant to educate trucking companies and drivers 

about the challenges of driving through mountainous areas. 

The program is a partnership among CDOT, the Colorado 

State Patrol, the Colorado Motor Carriers Association, and 

driver alert providers PrePass Safety Alliance and Drivewyze.

CDOT will implement the pilot program 

for the Mountain Rules on I–70.

Source: CDOT.

CDOT established the partnership after recent runaway 

truck incidents resulted in fatalities. Colorado’s high elevation, 

topography, and severe weather can present challenges for 

drivers, especially those maneuvering trucks. Long and heavy 

vehicles moving along a mountain corridor can sometimes 

experience brake failure.

The Mountain Rules will involve infrastructure and 

operational improvements, including signage displaying brake 

check locations along a portion of eastbound I–70, the 

primary east-west route in Colorado. CDOT will restripe an 

exit ramp at the Genesee Park interchange off I–70 and turn 

the space into a short-term truck parking area so that drivers 
PUBLIC ROADS • AUTUMN • 2019 • 23

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can allow their overheated brakes to cool and also perform 

equipment checks before entering the Denver area.

The program also will create a subscription-based, in-cab 

alert system that will warn truckers about specific areas where 

there are steep grades and provide locations for brake check 

areas and runaway truck ramps. Runaway truck ramps alongside highways are meant to give drivers a place to slow down 

when a vehicle loses its brakes while traveling downhill at a 

high speed. The Mountain Rules will gather information on 

the feasibility of new ramps and measures to mitigate 

runaway trucks.

The initial pilot for the program will take place on the I–70 

Mountain Corridor, which stretches between Glenwood 

Springs and the Denver metropolitan area. CDOT plans to 

expand the program to other mountainous locations.

Source: CDOT.

PennDOT Innovations Challenge 

Combats Roadway Litter

The Pennsylvania Department of Transportation (PennDOT) 

and the Pennsylvania Department of Environmental 

Protection recently announced that students in grades 9 

through 12 are invited to participate in the third PennDOT 

Innovations Challenge. The annual program encourages 

students to use their problem-solving, creative, and strategicthinking abilities to solve real-world transportation challenges 

in a competition among their peers. 

This year’s Innovations Challenge asks students to look at 

cost-effective technologies and innovative solutions that can be 

developed in the next 5 to 10 years to help PennDOT more 

efficiently, effectively, and safely control litter along roadways. 

Last year, PennDOT spent nearly $13 million cleaning up 

roadside litter across Pennsylvania. 

Regional Innovations Challenge winners will be invited to 

compete in Harrisburg for the State championship. This year, 

the Pennsylvania Chapter of the American Traffic Safety 

Services Association and the Keep Pennsylvania Beautiful 

organization are providing a combined total award of $3,000 

to be divided among the first-, second-, and third-place 

statewide winning teams. The deadline for submissions is 

December 20, 2019.

For more information, visit www.penndot.gov/innovation. 

Source: PennDOT.

This year’s PennDOT Innovation Challenge 

asks students to find innovative solutions to 

the problem of litter on roadways.

© Vitali Chesnokov / Shutterstock.com.

U.S. Secretary of Transportation Elaine L. Chao, center, is joined by representatives 

from 19 Latin American and Caribbean countries at the first-ever Americas 

Transportation Summit in June 2019.

Source: USDOT.

Secretary Chao Co-hosts First Americas 

Transportation Summit 

U.S. Secretary of Transportation Elaine L. Chao co-hosted the 

first-ever Americas Transportation Summit with InterAmerican Development Bank (IDB) President Luis Alberto 

Moreno in Washington, DC. The summit brought together 

delegations from 19 Latin American and Caribbean countries, 

including 9 Transport Ministers. The summit discussed vision

ary leadership to safely integrate innovation in transportation. 

The Americas Transportation Summit engages both the 

public and private sectors in exploring innovative practices to 

advance competitive, safe, and secure transportation services. 

The event gathered ministerial authorities from the region’s 

transport sector, recognized international experts, and repre

sentatives of the private sector. 

At the summit, Secretary Chao spoke with Latin American 

and Caribbean Ministers of Transport about the Department’s 

number one priority—safety—along with infrastructure 

improvements, investments, and emerging technology such as 

unmanned aerial systems (drones), autonomous (self-driving) 

vehicles, and commercial space. The leaders shared and 

exchanged information and best practices to address common 

transportation challenges. The historic summit was the firstever meeting between these Ministers of Transport, IDB, and 

the U.S. Department of Transportation.

To read Secretary Chao’s remarks from the summit, visit 

www.transportation.gov/briefing-room/remarks-americas 

-transportation-summit.
24 • PUBLIC ROADS • AUTUMN • 2019

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INTERNET WATCH

Crowdsourcing to Improve Traveler 

Information and Operations

by James Colyar

Travelers routinely turn to mobile applications and social 

media sources to help plan their trips and find information 

about traffic incidents, weather conditions, work zones, and 

more. Crowdsourcing turns transportation system users into 

traffic sensors, generating data that improve real-time opera

tions and enhance the overall management of transportation 

systems. By leveraging crowdsourced data from mobile apps 

and social media in combination with traditional data sources, 

State and local agencies can improve traveler information, 

traffic incident and work zone management, weather response, 

and more. 

“Crowdsourcing is a low-cost, powerful tool to overcome 

gaps in field instrumentation, data latency, and limitations 

inherent in traditional real-time monitoring,” says Valerie 

Briggs, director of the Federal Highway Administration’s 

Office of Transportation Management. “That’s why 

Crowdsourcing for Operations was selected as one of the 

innovations for round five of Every Day Counts.”

Crowdsourced data are available wherever and whenever 

people travel, offering visibility into suburban and rural 

networks where roadway sensor technology is cost-prohibitive. 

More than half of all State and many local transportation 

agencies already use some form of crowdsourcing. 

The Utah Department of Transportation’s (UDOT) Citizen Reporter app enables 

the public to submit hazardous road conditions. Mobile apps are one example of 

successful crowdsourcing methods being used across the country.

© UDOT.

Combining Data Sources

Some agencies have successfully applied an approach that 

integrates crowdsourced and traditional data to improve 

agency operations. For example, the Kentucky Transportation 

Cabinet (KYTC) has data-driven performance measures for 

winter operations by integrating multiple sources of crowdsourced data with traditional sensor and automated vehicle 

location data. This has resulted in improved snow and ice 

operations through better identification of corridors to treat 

and more effective distribution of treatment materials, and 

overall better use of taxpayer dollars.

KYTC’s traffic management center operators receive email 

notifications based on events from certain mobile apps to 

improve incident detection and response. Operators also use 

the integrated data to monitor work zones in real time and 

support research on traffic control performance. KYTC 

maintenance divisions use the data to identify and respond to 

issues ranging from potholes to missing signs. Planning, traffic, 

and environmental groups also rely on these data for improved 

analyses at lower cost.

Improving Traveler Information

To improve safety and increase information available to 

travelers, some States provide their data directly to crowdsourcing apps, or report crowdsourced data through State apps 

and websites. For example, the Port Authority of New York & 

New Jersey makes real-time work zone and incident informa

tion available to navigation platforms including Waze, Google 

Maps, and Apple Maps. The Michigan Department of Transport

ation has automated workflow at its traffic management 

centers to report crowdsourced incident data through the 

State’s traffic data systems, improving timeliness of traveler 

information. 

Other State departments of transportation have developed 

or are developing automated filtering and prioritization of 

crowdsourced data for management center operators. The 

Indiana Department of Transportation uses its Traffic Ticker 

tool to identify dramatic changes in speed, which enables 

quicker identification of incidents and congestion hotspots. 

Traffic management center operators note crowdsourcing 

brings incidents to their attention 10 or more minutes sooner 

than other methods and helps capture incidents that might 

otherwise go unnoticed.

For more information, contact James Colyar at 

james.colyar@dot.gov or Paul Jodoin at paul.jodoin@dot.gov. 

James Colyar is a transportation specialist on the 

Innovative Operations Strategies Team in FHWA’s 

Office of Transportation Management.
26 • PUBLIC ROADS • AUTUMN • 2019

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TRAINING UPDATE

Ensuring Quality 

Through Inspection

by Gay Dugan, Vanessa Almony, and Amber Clark

Proactive inspection of pavement at every stage of construction helps ensure the 

best outcomes for roadway surface conditions.

© DoublePHOTO Studio / Shutterstock.com.

Helping the Nation’s transportation workforce recognize and 

address significant causes of early asphalt pavement distress is 

a critical goal of the Federal Highway Administration’s Office 

of Infrastructure, Pavement Materials Team. To address this 

growing need and help achieve that goal, the National 

Highway Institute (NHI) developed the new instructor-led 

training, Constructing and Inspecting Asphalt Paving Projects 

(course 131139).

A Proactive Approach 

During the 2-day classroom training, individuals learn con

struction and inspection techniques that meet quality standards 

and technical specifications for asphalt paving projects. The 

course focuses on the importance of a proactive approach to 

managing and inspecting construction projects at every stage. 

Participants identify and solve associated problems, implement 

corrective actions, and document communications between the 

agency and contractor. An indepth review of the inspection 

process enables learners to leave the classroom ready to apply 

the knowledge and skills they need on site to maximize quality 

in construction projects. 

“We cover the gamut in this course—from typical precon

struction to the most important elements of laydown opera

tions and compaction including emphasis on joints,” says 

Jason Dietz, a pavement and materials engineer in FHWA’s 

Resource Center. “Not only does this course prepare partici

pants to identify best construction practices before, during, 

and after asphalt pavement placement, it also encourages them 

to consider minor to severe consequences that could result 

from poor construction practices.”

NHI developed Constructing and Inspecting Asphalt 

Paving Projects with a single goal in mind: quality. To achieve 

high-quality results on a project, inspectors must be know

ledgeable and proactive at resolving construction concerns and 

avoiding future problems with the pavement by insisting upon 

proper methods before and during construction on each 

project.

Who Should Participate

NHI recommends this course for individuals who are involved 

in the planning, construction, and review of asphalt paving 

projects and who must ensure that projects are built to 

required specifications. Participants may be relatively new to 

asphalt or general project inspection. However, those with 

broader experience also will find value in the course as they 

learn about innovations in asphalt pavement construction 

technology and share successful practices with their peers. 

Participants must complete a 5-minute online pre-assessment 

to identify their familiarity with their agency’s asphalt pave

ment construction and inspection standards.

This instructor-led training costs $525 per person and 

awards 1.3 continuing education units upon the successful 

completion of the course’s 13 hours of instructional time. 

For more information or to register for this course, visit 

www.nhi.fhwa.dot.gov. To sign up for alerts when a course 

session is scheduled, visit the individual course description 

page and select the “Sign Up for Session Alerts” link.

How to Host or Attend a Training Course

NHI invites professionals interested in earning continuing 

education units or professional development hours to visit 

www.nhi.fhwa.dot.gov to browse the complete digital course 

catalog, which lists more than 400 courses spanning 18 

program areas. Interested hosts can submit a Host Request 

Form or find more information about hosting NHI 131139.

NHI is approved as an Accredited Provider by the International 

Association for Continuing Education and Training (IACET). As 

an IACET Accredited Provider, NHI offers continuing education 

units for its programs that qualify under the ANSI/IACET 

Standard. Gay Dugan is an NHI training program manager. Vanessa 

Almony and Amber Clark are contractors for NHI. 
PUBLIC ROADS • AUTUMN • 2019 • 27

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COMMUNICATION PRODUCT UPDATES 

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 https://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).

Long-Term Pavement Performance (LTPP) Program Specific 

Pavement Studies (SPS) Development of Experiment Design: 

SPS-11 Asphalt Concrete Pavement Preservation Study 

Publication Number: FHWA-HIF-18-063

Pavement preservation represents a 

proactive approach to maintaining 

and extending the life of existing 

highways. Research findings over the 

past few years prove that pavement 

preservation can be a cost-efficient 

approach to extend pavement’s 

effective service life and improve 

safety and service condition.

This report documents the 

recommended experimental design 

for the Long-Term Pavement Performance (LTPP) SPS-11 

Asphalt Concrete Pavement Preservation Study. Researchers 

designed the study to establish the impact of selected preser

vation treatments on pavement performance under different 

loading and environmental conditions through a field study of 

inservice pavements starting from construction of the 

preservation treatments under consideration. The experiment 

focused on determining the best time to apply a preservation 

treatment on asphalt concrete pavement. 

The document is available to download at www.fhwa.dot.gov 

/publications/research/infrastructure/pavements/ltpp/18063 

/index.cfm.

Long-Term Pavement Performance (LTPP) Program Specific 

Pavement Studies (SPS) Development of Experiment Design: 

SPS-12 Portland Cement Concrete Pavement Preservation Study 

Publication Number: FHWA-HIF-18-064

This report documents the recom

mended experimental design for the 

LTPP study, SPS-12 Portland Cement 

Concrete Pavement Preservation. 

Researchers designed the study to 

establish the impact of selected 

preservation treatments on pavement 

performance under different loading 

and environmental conditions 

through a field study of inservice 

pavements starting from construction 

of the preservation treatments under consideration. 

The underlying concept of this experiment was to apply 

the same preservation treatment, at different times, on the 

same pavement structure to determine the effectiveness of a 

single application of a treatment as a function of pavement 

condition and time. The study will enable development and 

implementation of important pavement preservation products 

and tools, such as the addition of pavement preservation 

considerations to the American Association of State Highway 

and Transportation Officials’ (AASHTO) MechanisticEmpirical Pavement Design Guide and associated software. 

The experiment and this project report can be adopted and 

adapted by interested highway agencies to achieve the 

stated benefits.

The document is available to download at www.fhwa.dot.gov 

/publications/research/infrastructure/pavements/ltpp/hif18064 

/index.cfm.

Lightweight Concrete: Transfer and Development 

Length of Prestressing Strands

Publication Number: FHWA-HIF-19-018 

Advancements in concrete materials have led to significant 

enhancements in the performance of lightweight concrete. 

However, decades-old performance perceptions continue to 

hinder wider use of lightweight concrete. 

From 2007 through 2015, FHWA conducted a longrunning experimental study to investigate the structural 

performance of modern lightweight concretes. The overall 

study engaged the academic, public sector, and private sector 
28 • PUBLIC ROADS • AUTUMN • 2019

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communities to compile the body of 

knowledge on lightweight concrete 

while also conducting nearly 100 

full-scale structural tests on lightweight concretes.

This report presents the results of 

transfer length measurement and 

development length tests on pre

stressed girders made with highstrength, lightweight concrete, as well 

as a compilation of data available 

from the literature. It also provides potential revisions to the 

AASHTO Load and Resistance Factor Design Bridge Design 

Specifications, with a focus on transfer and development 

length of prestressing strands in lightweight concrete.

The document is available to download at www.fhwa.dot.gov 

/publications/research/infrastructure/structures/bridge/19018 

/index.cfm.

Lightweight Concrete: 

Transfer and Development 

Length of Prestressing Strands

Publication FHWA-HIF-19-018 February 2019

Research, Development, and Technology

Turner-Fairbank Highway Research Center

6300 Georgetown Pike 

McLean, VA 22101-2296

Simulator Assessment of Alternative Lane 

Grouping at Signalized Intersections 

Publication Number: FHWA-HRT-19-025

Simulator Assessment of Alternative

Lane Grouping at Signalized Intersections 

PUBLICATION NO. FHWA-HRT-19-025 MARCH 2019

Research, Development, and Technology

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101-2296

FHWA is focused on improving 

highway design by increasing knowl

edge of how intersection design 

affects operational efficiency and 

safety. Two intersection configura

tions designed to increase capacity 

without adding lanes are the dynamic 

reversible left-turn lane at diamond 

interchanges and the contraflow 

left-turn lane at signalized intersec

tions. FHWA researchers explored 

these configurations in the project “Simulator Assessment of 

Alternative Lane Grouping at Signalized Intersections.” This 

project consisted of two studies, both conducted in the 

Highway Driving Simulator at FHWA’s Turner-Fairbank 

Highway Research Center (TFHRC), which assessed driver 

behavior and comprehension in response to signs and symbols 

used to convey reversible-lane operations. 

Findings show that signs and markings used in both studies 

will work well in a real-world environment. The publication 

includes recommendations for additional and modified signs 

and markings on the approach sides of dynamic reversible 

left-turn and contraflow left-turn intersections to improve 

comprehension and comfort of drivers who may see opposing 

traffic in their lane while waiting for a green signal.

This report will be of interest to engineers, planners, and 

transportation professionals concerned with implementing 

signs and pavement treatments for alternative intersections and 

responsible for highway design and public safety.

The document is available to download at www.fhwa.dot.gov 

/publications/research/safety/19025/.

Formation Factor Demystified and Its Relationship to Durability

Publication Number: FHWA-HRT-19-030 

TURNER-FAIRBANK HIGHWAY

RESEARCH CENTER https://highways.dot.gov/research/

WHAT IS ELECTRICAL RESISTIVITY AND WHY IS IT MEASURED?

Electrical resistivity is a property that indicates the material’s resistance to the passage 

of electrical charges at a defined temperature. Concrete is a porous material and the 

porosity in concrete consists of a system of nano- and microscopic pores, interconnected 

at different degrees. In concrete, resistivity is directly proportional to the resistivity of the 

pore solution, and inversely proportional to the volume and connectivity of the pores. This

means that:

• The more pores and the more these pores are connected, the lower the resistivity

(Figure 1).

• The higher the concentration of ions in the pore solution, the lower the resistivity.

In other words, concrete resistivity depends on the pore structure and on the pore 

solution. While concrete resistivity measurements are used as a surrogate test by many 

state DOTs and commercial labs for durability testing and quality assurance purposes, 

these tests fail to capture the influence of the pore solution. 

Source: FHWA

Figure 1. Illustration. Applied charges through concrete with a) high connectivity

and b) reduced connectivity between macroscopic pores. 

i SES Group and Associates. ii SES Group and Associates.

iii FHWA contact: Ahmad.Ardani@dot.gov, 202–493–3422. 

FORMATION FACTOR DEMYSTIFIED AND ITS RELATIONSHIP TO 

DURABILITY

Jussara Tanesi, PhD., FACI, (i) Luca Montanari,(ii) and Ahmad Ardani, P.E.(iii)

(a) (b)

Electrical resistivity is a property 

that indicates the material’s resis

tance to the passage of electrical 

charges at a defined temperature, 

and many transportation depart

ments and commercial labs use 

concrete resistivity in durability 

testing. However, the formation 

factor can provide a better measure 

of durability by including consider

ation of the concrete pore volume 

and pore connectivity. 

This TechBrief aims to help practitioners understand 

concrete electrical resistivity—how it is measured, its limita

tions, and its relationship with durability—and explores the 

use of the formation factor as an alternative for testing 

durability. The publication discusses how the formation factor 

is obtained, the options to determine the pore solution 

resistivity (one of the necessary inputs for calculation of the 

formation factor), and the “bucket test,” an alternative to 

simplify the process.

The TechBrief highlights research currently being conducted at FHWA’s TFHRC. Researchers are working on 

closing the gaps for the reliable determination of the for

mation factor, focusing on aspects related to pore solution 

resistivity.

The document is available to download at www.fhwa.dot.gov 

/publications/research/infrastructure/pavements/19030/index.cfm.

Reporting Changes of Address

Public Roads has several categories of subscribers. Find your category below to learn how you can update your contact information.

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individuals who receive complementary copies and have an address change should send the complete previous mailing address and the complete new address to our 

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readers. The Public Roads editorial office maintains the mailing list for this group. Subscribers in this category can update their contact information by sending the complete 

previous email address and the complete new email address to our distribution manager, Lisa Shuler, via email (lisa.shuler@dot.gov), telephone (202–493–3375), or mail 

[Lisa Shuler, Public Roads Distribution Manager (HRTM), Federal Highway Administration, 6300 Georgetown Pike, McLean, VA, 22101-2296].
These CARMA3 vehicles are equipped

with the CARMA platform, which enables 

communication between vehicles and 

roadway infrastructure. Source: FHWA. 

Collaborate with 

FHWA’s software platform is facilitating a transportation 

transformation through automated vehicles. 

The Cooperative Automation Research Mobility 

Applications (CARMA) platform equips vehicles with 

the ability to interact and cooperate with roadway 

infrastructure and other vehicles—ultimately improving 

efficiency and safety and transforming transportation 

systems management and operations. 

CARMA is an open source software platform that runs 

on a computer installed in a vehicle. The computer 

interacts with the vehicle’s devices to enable 

cooperative automated vehicle maneuvers. 

Join the Collaborative 

The CARMA Collaborative is a growing 

community of CARMA users invested in 

developing intelligent transportation solutions. 

Please share this information with your 

professional associates. 

FHWA created the platform to be vehicle and 

technology agnostic, enabling a wide range of 

participants in the transportation industry to test 

it on their own vehicles. CARMA’s innovative 

approach and design encourages collaboration with 

industry, academia, and other public agencies on 

cooperative automation applications. 

For more information, visit https://highways.dot.gov 

/research/research-programs/operations/CARMA or 

contact Taylor Lochrane at Taylor.Lochrane@dot.gov. 
U.S. Department 

of Transportation

Federal Highway 

Administration

Attn: HRTM

1200 New Jersey Avenue, SE 

Washington, DC 20590

Official Business

Penalty for Private Use $300

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ADMINISTRATION

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