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1. What types of pollution effect transportation planning for the Metropolitan Planning Organization (MPO)?

See a listing of pollution types that have an effect on the planning process. Pollution Effecting Transportation Planning

2. What is conformity?

Conformity is the process of assessing the compliance of any transportation plan, program or project with air quality implementation plans. It is a way to ensure that Federal funding and approval are given to those transportation plans that are consistent with air quality goals. According to the Clean Air Act of 1991, transportation plans cannot:
- Create new violations of the Federal air quality standards.
- Increase the frequency or severity of existing violation of the standards.
- Delay attainment of standards

Because driving is so closely linked to air pollution, federal law requires the High Point Urban Area’s Long Range Transportation Plan to support the goals of North Carolina’s air quality plans. Without this “conformity”, the urban area risks losing its federal transportation funds.

3. How does conformity affect the MPO?

Under the Clean Air Act, States and MPOs must demonstrate, through the conformity process, that the transportation investments, strategies and programs they choose, taken as a whole, have air quality impacts consistent with those contained in the State Implementation Plans (SIP) for achieving the National Ambient Air Quality Standards.

If a transportation plan, program, or project does not meet conformity requirements, transportation officials have the following options:
- Modify the plan, program, or project to offset the expected emissions.
- Work with the appropriate State agency to modify the SIP to offset the plan, program, or project emissions.

If the above is not accomplished, and if a conformity determination cannot be made within certain time frames after amending the SIP, or if three years passes since the last conformity determination, a conformity lapse occurs and no new projects may advance until a new determination for the plan and Transportation Improvement Program (TIP) can be made.

4. What triggers a Conformity Analysis?

The following actions initiate the need for a Conformity Analysis:
- Establishment or Revision of the Emissions Budget. The State or Federal Government determines this need.
- Long Range Transportation Plan adoption or amendment
- Establishment or revision of Traffic Control Measures.
- For maintenance areas, a Conformity Analysis is required every 3 years.

In short, a new analysis is required whenever the transportation plan adds a project, deletes a project, significantly delays or accelerates a project, or changes the project scope.

5. What variables are considered when determining conformity?

Emission rate models (often referred to as the Mobile models) are used to estimate emissions for the area, taking into consideration factors such as the mix of vehicle types, temperature, etc. These rates are then applied to the vehicle miles traveled and speed estimates from the travel demand model to calculate motor vehicle emissions rates.

6. How do emission levels determine the classification of urban areas in reference to air quality?

Based on the air quality monitoring results, the area can be classified into the following categories.

7. What options are available to improve air quality?

These options are often referred to as Transportation Control Measures (TCMs). Funds are available from the State and Federal government to aid in the implementation of these strategies. Below is a list of traffic control measures and cost effective transportation strategies.
- Bike / Pedestrian Improvements
- High Occupancy Vehicle (HOV) Lanes
- Inspection and Maintenance Programs
- Park / Ride Lots
- Parking Pricing
- Reformulated Gasoline
- Ride-sharing
- Signal Timing
- Transit Improvement

8. Why are these options necessary?

Each of today’s cars produces 60 to 80% less pollution than cars in the 1960s. However, more people are making more vehicle trips. In 1970, Americans traveled 1 trillion miles in motor vehicles, and that was projected to increase to 4 trillion miles per year by the year 2000. Transportation options are the most effective means of reducing vehicle miles traveled, congestion, and pollution.

9. Why does air quality affect transportation?

Construction of wider roads reduces congestion temporarily. Once congestion is reduced with additional lanes, the roadway becomes more attractive to motorists until saturation is again reached. The addition of a project can also increase congestion on connecting roads. While congestion does contribute to pollution problems, it also serves as a means to deter added vehicle miles traveled. Thus, there is a need for transportation professionals to explore alternative forms of transportation.