MPC
Research Projects (2000-01)

Identifying Number

MPC-197

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 roadbed gravel being investigated, 2.5 miles of each and five different treatments. The treatments are magnesium Chloride, Lignon Sulfanate, a mixture of 50 percent Lignon Sulfanate and 50 percent Magnesium Chloride, a mixture of a Pennzoil and Lignon Sulfanate and a mixture of gravels while the Pennzoil mixes will be applied on only one gravel type. The remaining one-half 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 vendors will provide the dust suppressant. The Colorado State University Dustometer, developed in previous research supported by the MPC, will be used to quantify the amounts of dust released into the air from all the test and control sections. Measurements of drivability will be defined and measured (examples of drivability 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 five 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 March 2000)
• Task 2 – Apply the road dust suppressants to the one mile (changed to one-half 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, one-half 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, drivability measures will be made on each test section. (Student - started May-November 2000)
• Task 4 – Regrade the test sections without additional material and measure the same cross sections measured prior to the start of the tests. Apply the second treatment of suppressants. (Larimer County and student - Fall 2000)
• 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 and completion)
• Task 6 – Chip and seal test sections and the control section. (Larimer County - Fall 2001)
• Task 7 – Measure periodically the particulate emanation from all road sections using the Colorado State University Dustometer. (Student - Fall 2001)
• Task 8 – After a review and analysis of the date generated in the research thus far an interim letter report will be prepared and made available to all interested parties and with the permission of the MPC, it will be made available on the World Wide Web. (Sanders, Student - December 2000)

Mile stones, Dates

• Starting Date: July 1, 2000
• Project Milestones: Interim Letter Report December 2000
• Ending Date: June 30, 2001

Yearly and Total Budget

This is the second year of the project. Year 1 had a budget of $ 29,594 plus $48,496 CSU match for a Year 1 total budget of $78,090. The second year of the project, the amount requested is $18,000 from USDOT. A CSU match of $40,604 provides additional funding. The total budget for Year 2 is $58,604.

Student Involvement

Funds are included for the support of a graduate research assistant and for an hourly student. A technical report or MS thesis will result from this research.

Relationship to Other Research Projects

This research project is in its second year and is a continuation of a previously funded project in 1993 and 1994 by the MPC, 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 plains states, their results will be very helpful in the selection of suppressants to be used in this project and as a 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 as 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 than 100-120 in Colorado. We suspect that a road treated with 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 and seal