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Chapter 10
Roadside Management and Maintenance: Beyond Vegetation
10.14. Preserving Air Quality in Maintenance and Operations

Ozone Action Days

DOTs are beginning to partner with other state agencies and metropolitan regions to reduce ozone on red alert days and as part of larger partnership efforts. For example, New York State DOT partners with New York City and the New York Metropolitan Transportation Council to implement a coordinated regional clean air awareness program. Within the agency, NYSDOT works to reduce air quality effects from transportation by disseminating warnings of forecasted unhealthful ground level ozone conditions to a network of NYSDOT regional offices, local agencies, and interested parties. The warnings, along with recommended transportation actions to reduce emissions, are broadcasted to affected areas of the state. The information is transmitted electronically and by telephone and fax. Designated contacts at each receiving location then implement their action plans. New York agencies participating in this Ozone Action Days program deliver the alert information to the public through such means as variable message signs on highways, bridges, and tunnels; and the dissemination of the warnings to area employers and the media. [N]

Flex-time programs
Some DOTs have implemented flex time programs to contribute to the alleviation of congestion, air pollution, and ozone formation. DOTs have also provided shuttle services at the noon hour to help workers avoid having to drive to lunch.

Delaying or Rescheduling Ground Maintenance
A number of DOTs, including Georgia, New Jersey, and New York State, are delaying or rescheduling ground maintenance activities that require gasoline powered equipment such as mowers, blowers, weed-eaters, chain saws, etc. In some cases use of off-road construction equipment is delayed until after 6 p.m. as well.

Restricting or Limiting Painting
Georgia DOT is exploring restricting and/or limiting indoor and outdoor painting on Action days until after 6 PM or not at all on these days. New Jersey DOT also defers spraying and painting on Ozone Action Days. [N]

The Virginia DOT examined episodic limits on asphalt paving and traffic marking activities, in particular prohibiting road paving and traffic marking on ozone action days; however, the benefits from the possible control measures did not meet the NOx or VOC threshold necessary for implementation as a regional air quality control measure in Virginia. Asphalt paving has been found to have de minimis emissions; however reductions in traffic marking have been implemented by Maryland DOT and Montgomery County on Ozone Action Days. [N]

Regular Vehicle Maintenance and Tune-Ups

Most DOTs have programs to perform regular maintenance and tune-ups. Changing the oil and checking tire inflation can improve gas mileage, extend vehicle life, and reduce air pollution.

Wisconsin DOT operates a very effective inspection/maintenance (I/M) program. In 2002, WisDOT produced a report reviews the status of existing I/M programs in the United States and I/M research being performed by other states. The report also reviews the status of current I/M technology, including second generation onboard diagnostics (OBDII) testing, identification of liquid gasoline leakers, particulate/diesel emissions control program, remote sensing programs, toxic emission control programs, supplemental federal test procedure, and EPA activities related to I/M programs. The study concluded that additional research is needed to better define future I/M requirements. Key recommendations included the need for a malfunction indicator lamp response study, evaluation of stand-alone alternatives to centralized OBDII inspection, a determination on how to find vehicles with liquid leaks and other gross evaporative emission problems, and assessing the need for tailpipe tests on high mileage OBDII equipped vehicles. [N]

Alternate Fuel Vehicles and Refueling Stations

Some DOTs have been facilitating reduction in air pollution through the use of alternative fuel vehicles. The Colorado DOT has purchased electric bicycles for environmental staff at the District 6 office. Other DOTs and many municipalities have purchased cars and trucks powered by natural gas, hybrid, E85 (ethanol), and electricity.

The Central New York Regional Transportation Authority with the support of the United States Department of Transportation and the New York State Department of Transportation has been a leader in the testing and implementation of compressed natural gas as an alternative vehicle fuel. With a growing fleet of compressed natural gas busses, the agency needed a refueling station. Through interagency cooperation, public-private partnerships, and proactive public involvement, the team utilized Congestion Mitigation and Air Quality Improvement Program funding sources to build an indoor state-of-the-art compressed natural gas refueling facility. The project also included a public compressed natural gas fueling station, which has encouraged more widespread public and private vehicle fleet conversion to compressed natural gas in the greater Syracuse-Onondaga County area. The refueling station has provided many benefits to the surrounding communities by reducing air pollutants from mobile sources and has helped to improve the region's air quality by minimizing congestion and providing the added benefit of public transportation. [N]

Night Refueling and "Don't Top off the Tank" Policies

To reduce release of gas fumes in the air, some DOTs have encouraged employees to stop short of a full tank to reduce pollution. Refueling at night can also prevent gas fumes from heating up and creating ozone. Georgia DOT is among those implementing this approach. [N]

Truck Stop Electrification

The Congestion Mitigation and Air Quality (CMAQ) program supports improvements pertaining to operations. In 2003, FHWA issued expanded guidance and provided more information on the eligibility of truck stop electrification (TSE) and other idle-reduction measures under the CMAQ program. The guidance documents and other reference materials about the CMAQ program can be found online. The guidance notes that long-duration idling related to freight movement has become the norm for business operation at highway truck stops, airports, and at intermodal transfer points, emitting pollutants, consuming fuel, producing noise, and increasing maintenance costs. USDOT and EPA have formed a partnership to work with state transportation and environmental agencies, and MPOs to accelerate the implementation of TSE projects on routes heavily traveled by long-haul trucks, to identify appropriate locations and assist in jointly funding projects. CMAQ funded TSE projects must occur in close proximity to and primarily benefit a nonattainment or maintenance area and be included in a conforming transportation plan and TIP. Further information on alternatives to idling can be found at the CMAQ website.

Atmospheric Dispersion of Deicing Salt Applied To Roads

The Illinois Department of Transportation funded a study to understand and describe the atmospheric transport of road salt in the form of sodium chloride (NaCl) applied to highways as a deicing material, focusing on interstates in the Chicago area. Results from chemical analysis of aerosol and snow samples are reported that show progress toward characterizing the road salt aerosol with respect to its size, mechanisms of emission, range of atmospheric transport, and mechanisms of deposition. Analysis of the preliminary data suggest: [N]

  • A large portion of the salt aerosol that becomes aerosolized is emitted after the road surface has been cleared of snow and ice.
  • Approximately 90 percent of the airborne road salt is contained in aerosol particles of diameter larger than 2.5 micrometers ( mm) or 10 -4 inches.
  • The salt deposition pattern near a treated roadway as determined by snow samples decreases consistently with distance from the road. Average deposition values for a single snow event were found here to yield an aerial deposition of 0.06 grams per square meter (0.6 pounds per acre) at 500 meters (1,640 feet) from the road. The corresponding value for the total deposition per length of roadway is 85 grams per meter or g/m (300 pounds per mile or lb/mi).

Based on evidence from aerosol and snow sampling, the most important emission process is erosion of dried salt material from the roadway followed by dry deposition of the aerosolized salt material. A predictive atmospheric loading model is scheduled for completion in the last half of 2004. No practices to minimize atmospheric deposition from deicing salt are being recommended based on research to date. [N]

Open Burning

Open burning can produce hazardous contaminants, unreasonable smoky conditions, additional fire hazards, and unsafe driving conditions. In areas where open burning is regulated, such as cities, counties, state or federal lands (USFS-BLM), or where air quality standards are in effect, a burning permit is required and burning often will be allowed (if at all) only under very restrictive conditions.

Every attempt should be made to remove and dispose of flammable materials in approved locations such as landfills. Brush and small trees can be chipped and blown back on the right-of-way or hauled away and stored for later use as erosion control mulch. Brush mowing may be another alternative to consider, if practicable.

If it is determined that burning is the best or only suitable method of disposal, it should be done with all due caution, traffic control, and strict adherence to all applicable rules and regulations.


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Table of Contents
Chapter 10
Roadside Management and Maintenance: Beyond Vegetation
10.1 Environmental Enhancement Practices and Partnership Efforts
10.2 Protection of Historic and Other Cultural Resources
10.3 Maintenance in Wetlands
10.4 Maintenance Near Waterbodies
10.5 Maintenance of Structures for Wildlife
10.6 Maintenance of Stormwater Facilities
10.7 Maintenance of Roadside Public Facilities
10.8 Management of Portable Sanitary/Septic Waste Systems
10.9 Maintenance of Shoulders and Roadway Appurtenances
10.10 Sweeping and Vacuuming of Roads, Decks, Water Quality Facilities, and Bridge Scuppers
10.11 Maintenance Stewardship Practices for Slopes, Drainage Ditches, Swales, and Diversions
10.12 Erosion and Sediment Control in Maintenance
10.13 Recycling in Roadside Maintenance Operations
10.14 Preserving Air Quality in Maintenance and Operations
10.15 Painting Operation Stormwater BMPs
10.16 Road Waste Management
10.17 Stockpiling, Spoil Disposal or Placement of Inert Fill
10.18 Maintenance of Soils
10.19 Emergency Actions
10.20 Field Review of Roadside Maintenance Operations
Lists: Examples | Tables | Figures
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