Frequently Asked Questions

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Q1.  What can I do to reduce air pollution?

A1.  Particulate Matter Pollution

• Do not ride dirt bikes, ATV's or other off-road vehicles in prohibited areas or on windy days.
• Drive slowly on unpaved roads and other dirt surfaces.
• Stabilize bare earth with gravel, dust palliatives, vegetation and restrict access to avoid disturbing soil.
• Avoid using leaf blowers and other dust producing equipment.
• Avoid using a wood stove or fireplace on days with poor air quality.
• Avoid allowing diesel engines to idle.

      Ozone Pollution

• Avoid peak-hour travel.
• Drive slowly on unpaved roads and other dirt surfaces.
• Reduce travel on days when an Ozone high pollution advisory is issued.
  • Bring your lunch to work or eat in your cafeteria or surrounding restaurants.
  • Eliminate all unnecessary driving and (or) combine trips.
  • Ride the bus, carpool, vanpool, or telecommute.
  • Find a carpool or vanpool partner.
• Keep your vehicle properly tuned.
  • Keep your tires inflated to proper levels.
  • Change your oil every 3,000 to 5,000 miles.
• Make sure the fuel cap is tightly secured.
• Avoid spilling gasoline.
• Do not use your gasoline-powered lawn and garden equipment, especially before 4 p.m.
• Use alternatives to charcoal for outdoor barbecues.

Q2.  Can an individual really make an impact on air pollution/traffic congestion?

A2.  Yes. The 1996 Olympics are an excellent example of the difference that individuals make.  Despite having 1 million more people in Atlanta and some of the highest temperatures of the summer, the metro area did not record a smog exceedence during the Olympics due to the fact that residents chose commute alternatives such as transit and businesses implemented commute options programs including teleworking and compressed work weeks.  The region experienced a 22% reduction in driving and a 28% reduction in ozone concentrations.  According to a study conducted by the American Lung Association, this resulted in a 42% decrease in emergency room visits for children with asthma at various hospitals throughout the region.

Q3.  What is the impact of commercial vehicles on smog?  Are there too many of them for individual commuter change to make a difference?

A3.  It is true that commercial vehicles/tractor trailers, old school buses and other large vehicles (heavy-duty vehicles), easily identifiable by plumes of black smoke, often times pollute more per vehicle than the average commuter vehicle. However, the sheer volume of commuter vehicles makes commuter vehicles a threat to air quality that is equally as important.

Commuter vehicles (light duty vehicles) drive 87 percent of the vehicles miles driven on our roads (heavy-duty vehicles drive just 13 percent), making commuter vehicles the overwhelming cause of our traffic congestion problems.

It is easy to underestimate the large amount of air pollution caused by a single automobile. Yet the facts paint a different picture: the average passenger car emits more than 115 lbs. of smog-forming emissions each year (NOx and VOCs).  And, the average light truck or SUV emits almost 164 lbs. of smog-forming emissions annually.  However, because there are significanlty more passenger vehicles in our most congested areas, reducing the amount of single-occupant vehicles miles driven is one of the best options for improving air pollution and traffic congestion problems.

That does not mean that heavy-duty vehicles are off the hook.  Cleaner diesel fuel will be required nationwide in 2007, and cleaner technologies are available that can make diesel engines that use this fuel as clean or even cleaner than gasoline powered vehicles.(Source: U.S. EPA Web Site)

Q4.  What is/Is there a difference between smog and particle pollution?

A4.  Smog is a term that is used to define unhealthy air that we breathe.  This is ground-level ozone and particle pollution.  Therefore, particle pollution is smog, but smog does not exclusively refer to particle pollution.

Ground level-ozone is a caustic gas formed when nitrogen oxide and volatile organic compound emissions combine with summertime heat and sunlight to create ozone.  Ozone, an unstable molecule made up of three atoms of oxygen, 'oxidizes' with lung lining, triggering asthma attacks, a dry raspy throat and other measures.

Particle pollution is made up of tiny particles and aerosols that are put out into the air.  "Soot" is a term that is sometimes used to describe particle pollution.  However, this term can be somewhat misleading since the particles in question are very tiny.

Particle pollution comes from some of the same sources as ozone, such as power plants and auto exhaust.  However, unlike ozone, particle pollution is a year-round concern.

Q5.  What is the difference between attainment and conformity?

A5.  Any area in nonattainment is violating the national air quality standards or contributing to the violation of at least one of the six pollutants monitored.  The designation is based upon EPA's analysis conducted over a three year span through field work and evaluation of monitors at various locations.  Once designated, a date is set determining the year the area must meet attainment.  To meet attainment, the area must no longer be exceeding the allowable amount of pollution for which it was originally designated in nonattainment.

Conformity refers to the connection between air quality and transportation plans.  Conformity occurs when the emissions budget determined by the state and incorporated in the State Implementation Plan (SIP) is met in the TIP.  Transportation conformity is required in all nonattainment areas.  The transportation plan must show that the implementation of all the projects will not create new air quality violations, increase the frequency or severity of existing violations, or delay attainment in the area.  Conformity applies one year after official designation as a nonattainment area.  If the transportation plan does not demonstrate conformity by the applicable deadline, the nonattainment area will lapse.

Q6.  How does the process of air quality and transportation conformity work?

A6.  Since 1991, with the passage of the Intermodal Surface Transportation Efficiency Act (ISTEA) and subsequent update of the act in 1998 (The Transportation Equity Act for the 21st Century) known as TEA-21, metropolitan area transportation plans have been required to show conformity with federal Clean Air Act standards.  Under the Clean Air Act, every state must submit a State Implementation Plan (SIP) that shows how it will manage and reduce levels of major pollutants that are in violation of federal air quality standards.  This includes ground-level ozone and particle pollution.  The SIP sets an overall budget for allowable emissions for each pollutant in violation and allocates these emissions for each sector, including transportation.

Thus, transportation plans must show they will contain emissions within a certain level.  Failure to do this results in what is known as a "conformity lapse" (meaning that the transportation plan does not conform to its emissions threshold).  Any region in a conformity lapse can be prevented from using federal funding for any transportation project that will result in increased emissions;  i.e. any road expansion project.  Other so-called transportation control measures, however, continue to receive federal funding.  This includes all programs funded within the CMAQ program, such as bicycle/pedestrian projects, mass transit, and transportation demand management.

Q7.  Do idling cars contribute significantly to air pollution?

A7.  While personal idling time may be only a minute or two, multiplying that by the millions of drivers who may do it regularly while stuck in traffic, it adds up to a lot of wasted gas and extra pollution. The US EPA estimates that for every minute a typical auto engine sits idling it emits 6.6 grams of pollutants such as volatile organic compounds and nitrous oxides. If two million drivers stopped idling their cars unnecessarily for two minutes just once a week, it would reduce these emissions by over 1,500 tons.

Q8.  Will technology take care of car emissions?

A8.  Regulations and voluntary programs designed to improve vehicle and engine technology are greatly reducing mobile source emissions.  EPA studies show that today's cars emit 75 to 90 percent less pollutants (for each mile driven) than their 1970 counterparts, thanks largely to advancements in vehicle and fuel technology.  Unfortunately, in accross the state we are driving more cars a greater distance than we were in 1970, which negates some of the advances in cleaner fuel and technology.  In fact, levels of nitrogen oxides (NOx), one smog-forming chemical, have been on the rise in the last 20 years, while all other air pollutants have been declining, due in large part to more driving and other man-made activities that produce NOx emissions.

Q9.  Why are motorcycles allowed to use HOV lanes, but hybrids are not?

A9.  Motorcycles are permitted by federal law to use HOV lanes, even with only one passenger.  The rationale behind allowing motorcycles to use HOV lanes is that it is safer to keep two-wheeled vehicles moving than to have them travel in start-and-stop traffic conditions.  States can choose to override this provision of federal law, if they determine that safety is at risk. (Source: Federal Highway Administration, Office of Operations)

Hybrids cannot use HOV lanes because they use gasoline and produce fuel vapor emissions. In order to qualify to use the HOV with only a single passenger, a vehicle must meet clean fuel standards as set by the EPA. (Source: Georgia Department of Transportation)

Q10.  How do we determine a Smog Alert Day?

A10.  Every day of the year, a team of 11 forecasters from Georgia EPD and Georgia Tech meet at 1:30 PM to determine the next day's smog forecast.  These forecasters review air quality models, look at weather patterns (temperatures, sunlight or cloud cover, wind speeds, etc) and take into account issues that may affect traffic counts (workday vs. non-workday, holidays, etc.) to make a prediction.  The team's forecast is ready to be issued by 2 PM.  With over eight years of forecasting under their belts, they have an 86% accuracy rate for ozone predictions.  The team has only been predicting particle pollution levels for a short time, so they are still learning about how various factors can impact particle levels from one day to the next.

Q11.  Why are more areas in the state in nonattainment than a year ago? What are the effects?

A11.  Metro Atlanta has been an ozone nonattainment area since 1979.  There are five classifications for ozone nonattainment areas: marginal, moderate, serious, severe, and extreme.  The U.S. EPA has recently implemented new standards that measure ozone concentrations by an eight-hour rather than a one-hour time frame. The eight-hour standard has a lower threshold for acceptable ozone concentrations.  The implementation of this new standard set the stage for the expansion of the Atlanta nonattainment region and the inclusion of the Macon and Chattanooga metro areas, as studies of the air pollution levels in those areas show that they are violating the new standard.  In these metro areas and the state as a whole, significant increases in population and cars have contributed to the increasing pollution levels.

In the newly added counties, pollution sources will be inventoried (how much comes from cars and trucks; how much comes from industry, etc).  A plan will then be developed to bring the area into compliance with the ozone standard.  While motorists in the expanded areas could be required to have annual car emission inspections, that is not certain.  If compliance can be attained without emissions testing (through other smog-reducing activities), emissions testing may not be mandated.  Businesses in those areas may also be expected to curb emissions from manufacturing and other industrial practices.  Finally, the counties also could come under the jurisdiction of the Georgia Regional Transportation Authority, which has the power to impose transportation changes in bad-air areas, such as redirecting funding from road building to other transit options. 

Another reason for the addition of more counties in nonattainment is the more stringent definition by EPA of particulate matter as a pollutant.  A new, smaller particle, PM2.5, has been included among the list of pollutants for which an area can be included in nonattainment.  All 8-hour ozone nonattainment counties, plus a few more counties throughout the state, were deemed in violation of PM2.5 in December of 2005. (Source: EPA)

Q12.  How is the location of an air monitoring station decided?

A12.  The original focus of the monitoring network was on monitoring close to "point" sources (large facilities with high emissions).  As air pollution control strategies were successfully implemented and the emissions from large facilities were brought into compliance with air quality regulations, the focus has shifted to pollutants that are more of a regional problem.

Air monitoring stations are primarily used to house continuous instruments that measure "criteria" air pollutants (those that have established National Ambient Air Quality Standards).  Monitoring for particulate matter is often accomplished by setting up instrumentation on sampling platform.

Multiple factors are considered when deciding the location of air monitoring station.  Sites are selected based on the pollutant or pollutants to be monitored, the population density, proximity to other monitoring stations (including those in other states) and operational efficiency.  The U.S. EPA has developed siting requirements for each of the "criteria" air pollutants.  These requirements include distance from trees, buildings and roadways, distance from major point sources, and probe height.  Other factors include site security and access, availability of electricity and telephone service, aesthetics and local zoning issues, and long term (+10 years) site availability.  Unfortunately the ideal monitoring site is virtually impossible to acquire, especially in urban areas.  (Source: Deleware Department of Natural Resources & Environmental Control)

Q13.  How is the work-scope of a CMAQ project modified?

A13.  Prior to contract/MOA: The sponsor must submit a formal request to the GDOT project manager detailing the changes to be made and the reason for those changes.  Any funding difference is the responsibility of the sponsor, and all changes must abide by the goals originally defined in the application and through the CMAQ guidelines.  If the changes are approved, the sponsor will be notified by the project manager.

Under contract: Any changes to the work-scope or funding amounts must be approved by GDOT.  Significant changes require an amendment or supplement to the existing contract.  The amendment will detail the changes to be made and be signed by both GDOT and the project sponsor.

Q14.  What is a network year?

A14.  The network year is the year a project is listed in the transportation conformity determination model.  The network year usually consists of projects open to traffic within five years.