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UNPAVED ROAD Chemical Treatments
State of the Practice Survey

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Publication No. FHWA-CFL/TD-13-002
January 2013

Central Federal Lands Highway Division
12300 W. Dakota Ave.
Lakewood, CO 80228

Front Materials

Report cover


The Federal Highway Administration (FHWA) encourages programs that protect both the environment and the life of the roadway. Fugitive dust from unpaved roads threatens air, soil and water quality and roadside flora and fauna. This loss of material cause road surface deterioration , increases maintenance cost, and adds to the complexity of managing a network of unpaved roads.

This FHWA report called Unpaved Road Chemical Treatments, State of the Practice Survey provides insights into how road managers at various levels of municipal, county, state, federal and tribal government, private industry and academic institutions approach unpaved road management regarding the use of chemical treatments.

Signature - Michael Davies

Michael Davies, P.E., Director of Project Delivery
Federal Highway Administration
Central Federal Lands Highway Division


This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement

The FHWA provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. The FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Technical Report Documentation Page

1. Report No.
2. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle
Unpaved Road Chemical Treatments State of the Practice Survey
5. Report Date
January 2013

6. Performing Organization Code

7. Author(s)
Angela Kociolek
8. Performing Organization Report No.
9. Performing Organization Name and Address
Western Transportation Institute
P.O. Box 174250
Bozeman, MT 59717-4250
10. Work Unit No. (TRAIS)
11. Contract or Grant No.
12. Sponsoring Agency Name and Address
Federal Highway Administration
Central Federal Lands Highway Division 12300 W. Dakota Ave.
Lakewood, CO 80228
13. Type of Report and Period Covered
Final Report,
December 2009 - February 2010
14. Sponsoring Agency Code
15. Supplementary Notes
COTR: Roger Surdahl, FHWA-CFLHD. This project was funded under the FHWA Federal Lands Highway Coordinated Technology Implementation Program (CTIP).
16. Abstract

This report documents survey results regarding the state of the practice of using chemical treatments on unpaved roads. It provides insights into road manager choices and challenges and is useful supplementary reading to the accompanying Unpaved Road Dust Management, A Successful Practitioner's Handbook by Jones et al. (2013).

Roughly 80% of the survey respondents used chemical treatments for six or more years. Ninety eight percent (98%) of those indicated it was to control (fugitive road) dust, in part, to comply with federal regulations, for human and livestock health, in response to public complaints, or as a courtesy to the public. Other top reasons were to reduce maintenance costs and extend grader maintenance intervals.

The most common treatment method was spray-on surface application with the top three chemical treatments being magnesium chloride, calcium chloride, and lignin sulfonate, respectively.
17. Key Words
18. Distribution Statement
No restriction. This document is available to the public from the sponsoring agency at the website
19. Security Classif. (of this report)
20. Security Classif. (of this page)
21. No. of Pages
22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Symbol When You Know Multiply By To Find Symbol
in inches 25.4 Millimeters mm
ft feet 0.305 Meters m
yd yards 0.914 Meters m
mi miles 1.61 Kilometers Km
in2 square inches 645.2 Square millimeters mm2
ft2 square feet 0.093 Square meters m2
yd2 square yard 0.836 Square meters m2
ac acres 0.405 Hectares ha
mi2 square miles 2.59 Square kilometers km2
fl oz fluid ounces 29.57 Milliliters mL
gal gallons 3.785 Liters L
ft3 cubic feet 0.028 cubic meters m3
yd3 cubic yards 0.765 cubic meters m3
NOTE: volumes greater than 1000 L shall be shown in m3
oz ounces 28.35 Grams g
lb pounds 0.454 Kilograms kg
T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t")
  TEMPERATURE (exact degrees)  
°F Fahrenheit 5 (F-32)/9 Celsius or (F-32)/1.8 °C
fc foot-candles 10.76 Lux lx
fl foot-Lamberts 3.426 candela/m2 cd/m2
lbf poundforce 4.45 Newtons N
lbf/in2 poundforce per square inch 6.89 Kilopascals kPa
Symbol When You Know Multiply By To Find Symbol
mm millimeters 0.039 Inches in
m meters 3.28 Feet ft
m meters 1.09 Yards yd
km kilometers 0.621 Miles mi
mm2 square millimeters 0.0016 square inches in2
m2 square meters 10.764 square feet ft2
m2 square meters 1.195 square yards yd2
ha Hectares 2.47 Acres ac
km2 square kilometers 0.386 square miles mi2
mL Milliliters 0.034 fluid ounces fl oz
L liters 0.264 Gallons gal
m3 cubic meters 35.314 cubic feet ft3
m3 cubic meters 1.307 cubic yards yd3
g grams 0.035 Ounces oz
kg kilograms 2.202 Pounds lb
Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T
  TEMPERATURE (exact degrees)  
°C Celsius 1.8C+32 Fahrenheit °F
lx lux 0.0929 foot-candles fc
cd/m2 candela/m2 0.2919 foot-Lamberts fl
N newtons 0.225 Poundforce lbf
kPa kilopascals 0.145 poundforce per square inch lbf/in2

*SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380 (Revised March 2003)

Table of Contents

List of Figures

List of Tables


The author wishes to thank Roger Surdahl of the FHWA-CFLHD for the sponsorship and leadership.

For their help in promoting the survey, the author thanks Tina Barbaccia of Better Roads Magazine, Michele Beck of the Montana Local Technical Assistance Program (LTAP), Lorie Cover of the Idaho Technology Transfer (T2) Center, Mike Fitch of the Ohio Department of Transportation, Anthony Giancola of the National Association of County Engineers, John Kiefer of Michigan LTAP, Terry McNinch of Michigan LTAP, Russell Merle Jr. of the Clark County Department of Air Quality & Environmental Management, David Page of the Florida T2 Center, Carrie Plasters of EnviroTech Services, Dan Ratermann of the Missouri Association of County Transportation Officials, Bob Raths of the Association of Oregon Counties, Richard Rolland of the Tribal Technical Assistance Program, Mike Long, Chairman of the Transportation Research Board's Low-Volume Roads Committee, and others who may have regretfully been missed. The author is also very grateful to everyone who took the time to participate in the survey.

Finally, thanks to the staff at the Western Transportation Institute for their administrative support.

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