{Urban traffic}   {school bus}   {Construction Equipment}   {Parked trucks}   {lawn mower}

Connecticut's Transportation and Air Quality Challenges (PDF, 96k)

What are Mobile Sources?

Mobile sources include a variety of vehicles, engines and equipment, and can be classified as either on-road mobile sources (e.g. trucks, buses, passenger cars, motorcycles) or off-road mobile sources (e.g. construction equipment, lawn, garden and snow equipment, personal recreation equipment, marine vessels etc.).

Why Mobile Sources matter:

Mobile source pollution accounts for approximately fifty percent of all man-made air pollution emitted in Connecticut and throughout the Northeast.  This pollution affects human health and our environment. 

Emissions from mobile sources contribute to the formation of ground level ozone, which is the primary constituent of smog.   Ground-level ozone forms when components of mobile source emissions, such as volatile organic compounds (VOC) and nitrogen oxides (NOx), react in the presence of sunlight.  According to Connecticut's 2002 Emissions Inventory, 12% of total VOC emissions and 58% of total NOx emissions are shown to be transportation related.  Studies have shown that high concentrations of ozone near ground level are harmful to human health, wildlife, crops, and buildings.

2002 Connecticut Emissions Inventory

{NOx Emissions Graph}

In addition, whether fueled by gasoline or diesel fuel, mobile sources are significant contributors to measured levels of particulate matter (PM).  PM is the term for solid or liquid particles found suspended in the air.  Mobile sources of all kinds emit PM directly to the atmosphere through their exhaust and also contribute to secondary formation of PM in the atmosphere through chemical reactions.  Mobile source particulate emissions consist mainly of very tiny, fine particles, also known as PM2.5, that are less than 2.5 microns in diameter.  Fine particulate matter is a major health concern and contributes to unsightly haze. 

According to Connecticut's Greenhouse Gas Inventory, transportation emissions of greenhouse gases (GHG) make up 40% of the GHG inventory and are the leading source of GHG emissions in Connecticut.  GHG emissions are the cause of climate change.   

2001 Connecticut Greenhouse Gas Emissions Inventory

{GHG Emissions Graph}

The Future of Mobile Sources in Connecticut:

Connecticut’s non-attainment status for ozone and particulate matter requires strategies designed to reduce emissions of NOX, VOCs, sulfur dioxide (SO2) and PM2.5.  The mobile source sector is a significant source of these pollutants.  The state has recognized that diesel-powered engines produce black carbon, a significant contributor to global warming, and emissions of toxic air pollutants, along with carbon dioxide (CO2) and PM2.5.  Therefore, minimizing vehicle miles traveled (VMT) for the on-road sources, is an important strategy to improve Connecticut’s air quality.

State efforts to address Climate Change consider the substantial contribution of mobile sources to the state’s total annual emissions of CO2.  The Global Warming Solutions Act calls for a minimum of an 80% reduction of GHG emissions from 2001 by 2050.   Success in achieving this goal will require draconian measures directed at stationary, area and mobile sources, of which mobile sources will be a significant focus.  There are many mobile source options available that have not yet been fully realized, but their implementation will require a change in the transportation culture of Connecticut.

State-wide plans have been developed as part of an integrated approach to addressing air quality impacts from transportation sources. These plans include the 2005 Climate Change Action Plan, the Governor’s Energy Plan, the 2006 Connecticut Clean Diesel Plan, and the Global Warming Solutions Program, as well as the state’s  on-going SIP development.  Key transportation initiatives identified in these plans include:

• Reducing VMTs by 3% below anticipated 2020 levels of approximately 110 million VMT per day through identification of innovative VMT management opportunities including:
  • Encouraging transit, bicycle and pedestrian components for the strategic transportation network; and
  • Conducting feasibility studies for congestion pricing, and using location efficient mortgages to encourage shorter commutes;
• Encouraging inclusion of climate modeling data in repair/replacement of transportation infrastructure;
• Encouraging acquisition of vehicles meeting stringent emissions standards and using cleaner fuels;
• Implementing rail service between New Haven-Springfield;
• Implementing the New Britain-Hartford and Hartford East Bus Rapid Transits;
• Moving forward on the I-95 Corridor Coalition-Freight Initiative
• Reducing emissions from legacy fleets, in the transit, construction, school bus and motor transport sectors (some 40,000 vehicles in Connecticut) by means of:
  • Aggressive transition to newer, cleaner fleet vehicles;
  • Exploration of creative financing or incentives for retrofits; and
  • Developing financing options for stationary and on-board idle reduction technologies;
• Enhancing education and enforcement of the state’s existing anti-idling strategy;
• Maximize opportunities for achieving emission reduction from ports, rail and airports;
• Establishing incentive program to encourage clean technologies such as:>
  • Construction of biofuels production facilities;
  • Installation of alternate energy fuel pumps; and
  • Advocating for expanded fuel cell research;
• Decrease dependence on fossil fuels by reducing consumption by 20% by using alternate fuels;
• Evaluating the use of low carbon fuel standards, which take into account the energy used and emissions produced in processing fuels; and
• Investigating potential improvements in the state and regional transportation system that will reduce GHG emissions.

The  Connecticut Climate Change Action Plan of 2005 set forth 9 recommended actions for the future of Transportation in Connecticut. The main goal is to reduce GHG emissions by 0.35 million metric tons of CO2 equivalent from the Transportation Sector by 2010.  Accordingly, many initiatives have already been taken: