MPC
Research Projects (2001-02)

Identifying Number

MPC-217

Project Title

Road Dust Suppression: Effect on Maintenance, Stability, Safety and the Environment (cont.)

University

Colorado State University

Project Investigator

Dr. Thomas G. Sanders
Department of Civil Engineering
Colorado State University
(970)491-5448

External Project Contact

Mr. Dale Miller, Larimer County

Project Objective

The objectives of this continuing research project are to continue research started several years ago establishing the cost effectiveness of using chemical dust suppressants in order to increase the time between routine road maintenance on low-volume dirt roads, to determine the effect of road dust suppressants on the stability of a road base before and after chip and sealing, and to assess the environmental and safety impacts of road dust suppressants.

Project Abstract

This research project is a joint cooperative venture with the Larimer County Road and Bridge Division, Roadbind America Inc. and other dust suppressant venders. The research will be conducted on ten, half mile sections of road in Larimer County. There are two types of road bed gravel being investigated, 2.5 miles of each and five different treatments. The treatments are Magnesium Chloride, Lignon Sulfanate, a mixture of 50% Lignon Sulfanate and 50% Magnesium Chloride, a mixture of a Pennzoil and Lignon Sulfanate and a mixture of Pennzoil and Magnesium Chloride. The first three dust suppressants will be used on both gravels while the Pennzoil mixes will be applied on only one gravel type. The remaining 1/2 mile section of each gravel type will be a control, receiving no applications of dust suppressants. The county will provide all the labor and equipment for the preparation of the test sections and the venders will provide the dust suppressant. The Colorado State University Dustometer, developed in previous research supported by the Mountain-Plains Consortium, will be used to quantify the amounts of dust released into the air from all the test and control sections.

Measurements of drivebility will be defined and measured (examples of drivebility are braking distance and vibrations). A record of all accidents on the roads will be kept for the duration of the research. In addition, Larimer County records will be investigated to see if there is a relationship between the number of accidents(and fatalities) and the type of road treatment (or lack thereof) on the dirt roads. More than one county in the State may be investigated if better records are available.

Task Descriptions

• Task 1 – Find and prepare a dirt road in Larimer County which will be chipped and sealed in the next few years to be used in the tests. This was done in the Spring so that tests can be made during the summer. The road available is five miles long.(Larimer County & Sanders, completed)
• Task 2 – Apply the road dust suppressants to the one mile (changed to 1/2 mile due to the number of dust suppressants to be tested and the availability of roads) test sections and prepare the untreated control section exactly the same way except no chemical treatment. Measure at least 5 cross sections of each of the test sections and install vehicle counters. As an additional variable, two different road bases were added to the research project making a total of 10, 1/2 mile road sections to be tested, 6 of one road base and 4 of the other.(Larimer County, completed, May, 2000).
• Task 3 – Make three dust measurements per section per day once a week until a second treatment of the suppressants using the Colorado State University Dustometer. In addition drivebility measures will be made on each test section.(Student, started, May 2000 and continuing through June, 2002)
• Task 4 – Regrade the test sections without additional material and measure the same cross sections measured prior to the start of the tests.(Snow came early and put off measurements and regrading until Spring, 2001) Apply the second treatment of suppressants. (Larimer County and Student, to be completed this summer, 2001).
• Task 5 – Keep records of all road accidents during the duration of the tests and investigate county records for a relationship of road accidents and road treatments.(Student, Project beginning-April, 2002).
• Task 6 – Chip and seal test sections and the control section. (Larimer County, June, 2002)
• Task 7 – After a review and analysis of the data generated in the research a final report will be prepared and made available to all interested parties on the MPC web site. An early snow fall prevented completion of the regrading and second treatment of the suppressants (Sanders and Student, Summer, 2002).

Milestones, Dates

• Starting Date: July 1, 2000
• Project Milestones: Interim Letter Report, Summer, 2001, see above Action Items and time table
• Ending Date: June 30, 2002

Yearly and Total Budget

This is the third year of the project, although it began midway into Year 1. The budget is as follows:

• First year: $29,595 USDOT + $48,497 CSU match = $78,092 Total
• Second year: $18,000 USDOT + $40,604 CSU match = $58,604 Total
• Third year: $12,362 USDOT + $40,875 CSU match = $53,237 Total

Student Involvement

Funds are included for partial support of a graduate research assistant and for an hourly student laborer. A technical report or M.S. Thesis will result from this research.

Relationship to Other Research Projects

This research project in its second year is a continuation of a previously funded project in 1993 and 1994 by the Mountain Plains Consortium assessing the effectiveness of various road dust suppressants. In addition, the Colorado State University Dustometer, an inexpensive dust measuring device was developed during the project. This research will also complement the research on chemical additive usage on unpaved roads in the mountain plains states by Birst and Hough. Since Birst and Hough's work summarized a survey regarding the use of chemical dust control/soil stabilizers by county engineers in the six Mountain-Plain states, their results will be very helpful in the selection of suppressants to be used in this project and as source for qualitative assessments of the effectiveness of the different chemicals.

Technology Transfer Activities

The most likely beneficiaries are all the county road departments in the USA responsible for the maintenance of dirt roads.

Potential Benefits of the Project

Potential benefits of the research may change the way the majority of the low-volume dirt roads in the United States as well around the world are maintained. Our previous research has shown that it is cost effective to use dust suppressants on roads having ADT's greater that 100-120 in Colorado. We suspect that a road treated with road dust suppressants for several years prior to chip and sealing will last longer than those without treatment. If proven true, this may cause a paradigm shift in low-volume dirt road maintenance. In addition the impact to safety and the environment may be sufficient to use dust suppressants on all dirt roads regardless of ADT's. The decrease of fines in the air will reduce air pollution significantly in the rural and nearby urban environments. Visibility and road stability are improved with the use of dust suppressants which will decrease road accidents and improve safety. The results of the research will be submitted for publication in major peer review, transportation journals such as the ASCE Journal of Transportation Engineering.

TRB Keywords

Dust suppressants, environment, safety, deferred maintenance, drivability, chip & seal