Center for Environmental Excellence by AASHTO CENTER HOME  
skip navigation
 New on the Website
 Web Watch
 Get Website Updates
 Get Broadcast E-mail
 Share Info with AASHTO
 Site Directory
 AASHTO Home
Print This Page
Air Quality

Overview | Recent Developments | Research, Documents & Reports
Case Studies | Organizations & Training


Case Studies  

Listed below are examples of success stories, best practices, and/or innovative tools/approaches. This section will grow as entries are submitted or links to other sites with useful examples are provided. If you believe your agency has utilized a best practice/approach that others could learn from, please submit a short description to AASHTO (including any pertinent links) on the Share Info with AASHTO form. Please note that currently submissions are only being accepted from governmental entities.

 
Colorado

HOP and the SKIP transit services
The HOP and the SKIP transit services in Boulder are helping the city to meet both its air quality and congestion relief goals by providing easy access and frequent service for its citizens. This FHWA 1999 Environmental Excellence Award winning program provides services to close to 10,000 riders per day.
 FHWA 1999 Environmental Excellence Award winner.

[back to top]

Connecticut

Implementation of Retrofit Program for Diesel Equipment During the Construction of the I-95 New Haven Harbor Crossing Project
The I-95 New Haven Harbor Crossing Improvement Program (NHHC) administered by the Connecticut DOT consists of the construction of a new State Street Commuter Railroad Station, the widening of I-95 from Exit 46 in New Haven to Exit 54 in Branford, the replacement of the existing Pearl Harbor Memorial Bridge (Q Bridge) with a new 10-lane bridge, and the reconstruction of the I-95/I-91/Route 34 Interchange.  

The project is located in the municipalities of New Haven, East Haven and Branford, which are a serious non-attainment area for ozone (O3).    The New Haven area only is a non-attainment zone for PM10 and PM2.5.   The construction of this 7.2-mile corridor, which started in 2002 and will take more than twelve years to complete, will include more than 200 pieces of diesel powered construction equipment.   Construction is divided in five phases under four major contracts.   The first contract was completed in June 2004.

In October 2000, the DOT formed an air quality working group, which investigated the benefits and costs of implementing a diesel emission control program.   The group included personnel from various offices within DOT, and experts from the New England States for Coordinated Air Use Management (NESCAUM), Connecticut Department Environmental Protection (DEP), Department of Motor Vehicles (DMV), and Connecticut Construction Industries Association (CCIA).   It was decided early on that the diesel emission control program called “Connecticut Clean Air Construction Initiative” would combine non-road diesel powered equipment control technology with the inspection of highway diesel vehicles.   The highway diesel vehicles are already regulated by the DMV under a heavy-duty diesel emissions regulation.    

Considering that this was a voluntary pilot program for DOT, it was decided that the most widely accepted technology and fiscally responsible emission reduction options would be used.   As such, the following technologies were selected:  

  • Oxidation catalysts due to its wide acceptance and proven experience, and
  • Clean fuels listed with the U.S. Environmental Protection Agency or the California Air Resources Board which could achieve specific NOx and PM emissions reductions.
The most positive aspect of initiating the retrofit program was the creation of an air quality-working group that met on a regular basis (every six weeks) almost one year before the bid documents had to be ready for the advertising of the first contract.   It was also critical to include the requirement for emission control equipment in the contract’s bid package.   By doing so, the cost of the retrofit equipment was included as part of the overall contract cost, thus avoiding the use of economic incentives to bring contractors into the program.   The I-95 NHHC diesel retrofit program proved that retrofitting construction equipment with oxidation catalysts is very feasible, and that it has significant benefits in terms of emission reductions, odor control, and visible smoke.   When considering that the costs of the oxidation catalysts are on the order of one percent of the total cost of the construction equipment to be retrofitted, and that the emission reductions are in the order of 20 to 50 %, this program has proved to be a very effective way to reduce diesel emissions and odor.  

For more details about this project, read a copy of a paper presented at the 2005 Annual Air and Waste Association Conference.

[back to top]

Florida

Orlando Bikeways
City of Orlando; Orlando, Florida.

The City of Orlando developed the Orlando Bikeways program to make bicycling safer and encourage the use of this alternative transportation mode. Orlando has achieved this goal by increasing its bikeways from three miles to over 150 miles in the last 12 years. The City has publicized and promoted bicycling in numerous other ways, such as by expanding the bike units and teams of the Orlando Police and Fire Departments, increasing bicycle parking availability, and establishing an annual "Bike to Work" day, led by the Mayor.
 EPA 2002 Clean Air Excellence Award winner

[back to top]

Maine

Air Quality Legislation to Reduce Greenhouse Gas
Maine Greenhouse Gas Initiative

The Maine State Legislature passed “An Act to Provide Leadership in Addressing the Threat of Climate Change,” which set goals for the reduction of greenhouse gas emissions within the state. These goals, the first in the nation established by state statute, call for a reduction to 1990 levels by 2010, to 10% below 1990 levels by 2020, and in the long-term reductions “sufficient to eliminate any dangerous threat to the climate.” A 32-member Stakeholder Advisory Group consisting of representatives of government, business, non-government groups, an academic resource panel, and DEP staff was established to consider climate change issues and potential approaches to mitigating Maine’s greenhouse gas emissions. The group advised DEP in the development of A Climate Action Plan for Maine 2004 with 54 recommended actions for achieving the goals for reduction. The plan lists the 54 actions in decreasing order of expected greenhouse gas savings, and provides for the evaluation of progress toward meeting reduction goals, reviews the cost-effectiveness of the actions, and provides for the submission of an annual progress report.

The Maine Greenhouse Gas Initiative website provides additional information and resources at http://www.maine.gov/dep/air/greenhouse/

 

[back to top]

Massachusetts

Implementation of Dust and Diesel Emission Control Programs for the construction Phase of the Central Artery/Tunnel Project
The Central Artery/Tunnel (CA/T) Project administered by the Massachusetts Turnpike Authority (MTA) consists of a new third harbor tunnel (named the Ted Williams Tunnel) which opened to commercial traffic in 1996 linking downtown Boston to Logan Airport in East Boston, and a new underground eight- to ten-lane Central Artery, which replaced Boston's elevated north-south I-93 expressway, and a ten-lane cable stayed bridge crossing the Charles River. The project opened to general traffic in 2005.

Project construction consisted of a total of 161 lane miles of new highway in a 7.5-mile long corridor, of which approximately one half was in tunnels. Construction included approximately 13 million cubic yards of excavated earth material and 4 million cubic yards of concrete, which were hauled in more than a half of million truckload trips. During mainline construction hundreds of pieces of heavy construction equipment were being used 24 hours per day, including large excavators, front-end loaders, bulldozers, cranes, cement trucks, and both 10-wheel and 18-wheel dump trucks.

Given the urban setting of the CA/T Project, with close proximity of construction activities to residential communities, medical facilities, businesses, and other sensitive abutters along the project alignment, stringent dust and odor control measures were implemented to protect public health. As part of the mitigation measures the CA/T project established a dust control specification, outlining the necessary measures and requirements that the contractors must follow in order to control on- and off-site nuisance dust. These included: reducing the number of truck entrances and exits from a site within the contract; providing a crushed stone base for the dump trucks in the on-site loading area; installing wheel wash stations at construction areas exits, daily use of watering trucks and street vacuum sweepers, and creating embankments between stockpiles and haul roads. These particular measures were implemented to manage and reduce dirt tracking.

To evaluate the effectiveness of these measures, and assist enforcement of them, the Project undertook a PM10 monitoring program. The monitoring program included the use of portable monitors located at sidewalks during the summer season measuring 24-hour PM10 levels twice a week at 5 to 10 locations per year, tracking emissions at the largest construction areas. A field dust inspection program was also implemented to verify contractor’s compliance with the specification requirements. The results of these programs concluded that most of the PM10 increases were localized, and confined to areas close to the major CA/T construction activities. The observations of the inspection program also concluded that the single most significant source of the high PM10 levels was re-suspended dust from construction trucks entering and exiting the construction areas. Strict enforcement of dust control specifications achieved approximately 50% reductions in peak PM10 levels.

During 1998, in conjunction with Massachusetts Department of Environmental Protection (MDEP) and the Northeast States for Coordinated Air Use Management (NESCAUM), the project also implemented an emission reduction diesel retrofit program for off-road construction equipment using oxidation catalysts. This program resulted in well over 100 pieces of diesel powered equipment being retrofitted. Based on EPA certification data, it was anticipated that oxidation catalysts would achieve at least 20 percent reductions for PM, 40 percent reductions for CO, and 50 percent reductions for HC in all heavy-duty engines.

[back to top]

Montana

VOC Reductions During Asphalt Placement
Historically the Montana Department of Transportation (MDT) used a product called MC-70, an asphalt cutback product, for priming new gravel surfaces prior to placement of the first lift of pavement on its construction projects.   The carrying agents for the asphalt in the MC-70 are volatile organic compounds (VOC’s).   VOC’s comprise approximately one-third of the MC-70 product by volume.   This was an effective product for use as a priming agent, as the high VOC’s in this product helped the base asphalt in the MC-70 penetrate effectively into the top of the aggregate surfacing, and promoted a good bond between the first lift of the new pavement and the underlying aggregate surfacing.   However, the MDT was concerned about the large amount of VOC’s that escaped into the atmosphere with the use of this product.

The MDT began trials of other products in 2001 and 2002 to find an effective prime treatment that did not result in the release of large quantities of VOC’s.   The MDT settled on the use of a dust palliative (magnesium chloride in most instances), followed by the application of SS-1, an emulsified asphalt product that has the same base asphalt as MC-70.   The dust palliative, with its affinity for moisture, helps draw the SS-1 down into the aggregate surfacing, thereby promoting the bond between the aggregate surfacing and the first lift of new pavement.   While the new prime process is more difficult to construct, and is marginally less effective in penetrating into the aggregate surfacing in some instances, the MDT is committed to this process primarily for the environmental benefits it has over the former process.   The MDT has not used the MC-70 product in its construction projects since June of 2003.

Had the MDOT continued its use of MC-70 approximately 2,000 metric tons of VOC’s would have been released into the atmosphere. 

[back to top]

New York

Ozone Action Days - notification/public outreach
The Ozone Action Days program is an effort of public outreach and education being implemented in the New York Metropolitan Area region to reduce emissions of volatile organic compounds (VOC) and nitrogen oxides (NOx) from transportation related activities. This program has been in place since 1997 and includes ozone forecasting, public notification of impending unhealthful ozone levels, public education, and outreach with the goal of persuading motorists to develop and use transportation modes other than single occupant vehicles (SOV) during periods of unhealthful ground level ozone concentrations. As more drivers participate in the program, fewer vehicles crowd the highways, congestion decreases, and commute speeds are optimized, all contributing to reduced emissions and ground level ambient ozone concentrations.

A number of strategies are employed to inform the public that unhealthful ozone levels are forecasted, including public service announcements, e-mail alerts, advertising, and announcements on highway variable message signs.  There are currently more than 500 business partners participating in the Ozone Action Days program. Their responses to an alert vary, from conveying the message to employees to measures that may include subsidizing vanpools or special incentives to encourage employees to use transit on alert days.

[back to top]

Compressed Natural Gas Refueling Stations
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 buses, the agency needed a refueling station. Through interagency cooperation, public-private partnerships, and proactive public involvement, the team used Congestion Mitigation and Air Quality Improvement Program funding sources to build an state-of-the-art indoor 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 benefited the surrounding communities by reducing air pollutants from mobile sources and has helped to improve the region's air quality by minimizing congestion and supporting public transportation.  This project won an Environmental Excellence Award from the Federal Highway Administration in 2001.
 Environmental Excellence Award from the Federal Highway Administration in 2001

[back to top]

The Central New York Regional Transportation Authority's indoor state-of-the-art compressed natural gas refueling facility
The Central New York Regional Transportation Authority, through interagency cooperation, public-private partnerships, and public involvement, built an indoor state-of-the-art compressed natural gas refueling facility to fuel its growing fleet of compressed natural gas busses. The project, which included a public compressed natural gas fueling station, helped spur widespread fleet conversions in the area to compressed natural gas and helped reduce mobile source emissions. The Central New York Regional Transportation Authority’s indoor state-of-the-art compressed natural gas refueling facility, New York.
 FHWA 2001 Environmental Excellence Award winner

[back to top]

VPSI, Inc,; Worldwide

VPSI Commuter Vanpools, VPSI, Inc.; Worldwide.

For over 25 years, VPSI has provided commuters with a viable, cost-effective, commuting alternative. VPSI vanpools provide over 30,000 commuters daily with a way to contribute to improving air quality while minimizing traffic congestion. With over 3,500 vehicles in service nationwide and in Europe, VPSI has created a sustainable program with continuous and replicable air quality benefits.

 EPA 2002 Clean Air Excellence Award winner
 

[back to top]

 
EPA Announces 2005 Clean Air Excellence Awards

Sixteen projects by individuals, state and local governments and other organizations were honored April 6 for contributions to improving air quality. Categories for the 2005 awards include: Clean Air Technology; Community Development/Re-development; Education/Outreach; Regulatory/Policy Innovations; Transportation Efficiency Innovations; Thomas W. Zosel Outstanding Individual Achievement Award. Access the EPA Clean Air Excellence Web Site

[back to top]

 
EPA's 2001 Clean Air Transportation Communities Grants Program

This EPA grants program supports voluntary cooperative projects that promote transportation efficiency measures within the United States, encourage development patterns that reduce the growth in vehicle miles traveled (VMT), and expand the availability of environmentally-sensitive transportation alternatives. Priority areas included projects that addressed smart growth, commuter choice, and green fleet/clean vehicle initiatives.

[back to top]

 

Overview | Recent Developments | Research, Documents & Reports
Case Studies | Organizations & Training

skip navigation