2. Research Needs by Focus Area

In the 2000 to 2004 PM research plan (Carr et al., 2002a) , five research focus areas were identified by the research community and transportation professionals. Five similar research focus areas were used to organize the literature assessment completed to develop this Strategic Plan (Tamura et al., 2005) . In the literature assessment, research issues were identified by focus area in tables at the beginning of each section; these tables have been updated in Appendix B of this document to reflect the priority of each need as discussed at the workshop.

This discussion section lists each of the five research focus areas and identifies the high-, medium-, and low-priority research needs in each focus area. Since Sections 3, 4, and 5 of this document are organized by research priority (high-, medium, or low-priority, respectively), this Section is intended to help readers find descriptions of research needs by focus area. More complete descriptions of important research needs are included in the Sections that follow.

2.1 Basic Research

• Monitoring. Ambient measurements of PM and precursors at outdoor locations ranging from sites near roadways, to neighborhood scale, to urban scale, or to rural sites. Monitoring in this context does not include emissions measurements.

  Research Needs:

  • High. Monitor near roadways.
  • Medium. Improve PM measurements. Increase the spatial extent and temporal resolution of PM measurements.
  • Low. None

• Characterization. The use of air quality or source receptor models and methodologies to relate ambient concentrations to local emissions sources, upwind sources, and meteorology. These tools are typically used by air quality planning agencies. This topic area does not include the emission or hot-spot models typically used by transportation planning agencies.

  Research Needs:

  • High. None
  • Medium. None.
  • Low. Support air quality model evaluations and improvements. Determine contribution of mobile sources to ambient PM contributions. Provide adequate data to support air quality model evaluation.

• Emissions Measurements. Direct quantification of vehicle emissions using tools such as dynamometers, remote sensing devices, and evaporative emissions sheds. This research focus area was identified as "Transportation Sources" in the 2000 to 2004 PM research plan.

  Research Needs:

  • High. None
  • Medium. Collect information on fugitive dust emissions. Evaluate roadway project effects on emissions. Collect exhaust emissions from gross-emitters.
  • Low. Improve information on ultrafine particles in exhaust. Collect exhaust emissions for non-gross-emitters. Evaluate dilution issues for condensable mass.

2.2 Applied Research

• Emissions and Hot-spot Models. Models that are used to calculate the emissions or impact of emissions on ambient air concentrations near roadways. This research focus area was identified as "Modeling" in the 2000 to 2004 PM research plan.

  Research Needs:

  • High. Evaluate hot-spot models. Develop and evaluate PM emissions models.
  • Medium. Create short-term MOBILE6.2 fixes. Improve information for MOBILE6.2 users regarding default assumptions. Estimate uncertainty in the air emissions/planning/air quality process.
  • Low. Develop models for ultrafine particles. Ensure that hot-spot and air quality models start where emissions models end.

• Control Strategies. Measures used to reduce emissions with the intended consequence of improving air quality.

  Research Needs:

  • High. Evaluate control strategy programs.
  • Medium. Compile a compendium of control strategy information. Create a data information repository for MPOs/DOTs.
  • Low. Develop guidance for weighing offsetting air quality and transportation goals (ozone, PM, air toxics, safety, and mobility).

For comparison, the research focus areas, key questions, and proposed projects from the 2000 to 2004 PM research plan are shown in Appendix C.