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October 24, 2018
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Home > Transportation > Planning Activities > Air Quality

Air Quality Planning in The Washington Region

Transportation planning in the Washington region is heavily influenced by air quality planning. Like financial constraint, air quality conformity is a federal requirement. Once the CLRP is drafted, it is tested to ensure that the projects in the plan, when considered collectively, contribute to the air quality improvement goals embodied in the Clean Air Act Amendments of 1990. A series of tests are performed with computer models that predict how much air pollution will be generated over the next 25 years by facilities in the plan, and how much the air will be improved by cleaner gasoline standards and many other factors.

If the CLRP is found by the TPB to meet regional air quality goals, federal agencies certify that the plan is "in conformity." In other words, the TPB ensures that the CLRP "conforms" to air quality improvement goals. A conformity determination lasts three years - the life of the CLRP itself. If the TPB encounters difficulty in meeting conformity - or expects to - it may choose to adopt Transportation Emission Reduction Measures (TERMs), such as ridesharing and telecommuting programs, improved transit and bicycling facilities, clean fuel vehicle programs or other possible actions. This information is documented in an Air Quality Conformity Determination report. Below is the currently approved Air Quality Conformity Determination report for the Washington Metropolitan Region.

Air Quality Conformity Analysis of the 2015 CLRP and the FY 2015-2020 TIP

The Air Quality Conformity Analysis of the 2015 CLRP and FY 2015-2020 TIP was approved by the TPB on October 21, 2015. The full Conformity report is available here for review.

Transportation Control Measures (TCMs)

The transportation conformity rule and the Clean Air Act require that Transportation Control Measures (TCMs) in approved State Implementation Plans (SIPs) be implemented. In the document below, Table 1 lists all TCMs included in the Washington DC- Maryland-Virginia Region's 1-Hour Ozone SIP (adopted by the Metropolitan Washington Air Quality Committee- MWAQC on 2/19/04), the 8-Hour Ozone SIP (adopted by MWAQC on 5/23/07), and the PM2.5 SIP (adopted by MWAQC on 3/7/2008). Following the table are letters confirming the implementation of each TCM.


Program Contact: Jane Posey - (202) 962-3331

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Air Quality Planning
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