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Eigth Year (FY 1999)

Analysis of Air Quality Emission Benefits

Overall Analysis

Based on the State annual reports submitted to FHWA, the total number of proposals with accompanying emissions reductions analyses was 653 for VOC, 345 for carbon monoxide (CO), 575 for nitrogen oxides (NOx) and 52 for PM-10. The range of emissions reduction potential for each of the major transportation-related emission types is provided on the following pages as shown in Figures 3 through 6 (x-axis represents the number of projects and the y-axis represents kilograms per day).

Emission reduction estimates were provided for particulate matter emissions only for a limited number of projects, as has been noted in previous annual CMAQ reports. This is understandable since no federally approved method existed for the analysis of PM-10 emissions. In FY 1998, 99 CMAQ projects were reported as having quantified particulate matter reductions compared to 52 in FY 1999. Twenty-six of these projects were estimated to reduce less than 5 kilograms per day or less. However, 11 were estimated over 100 kilograms per day and three were estimated to produce benefits of over 1000 kilograms per day.

In addition to the projects that have emission reductions submitted for this year, there are two additional types of projects that do not have current reported benefits. They are termed the Qualitative Assessment and the Previously Reported projects.

Not every air quality beneficial proposal is able to have calculated numerical emission reductions. Some projects can logically be considered to have air quality benefits but not lend themselves to numerical quantification. Such proposals can be eligible for CMAQ funding if the project sponsor submits an acceptable description of how the project would lead to emission reductions. Such a description is called a Qualitative Assessment and, each year, there are a number of projects that become eligible for CMAQ support in this manner.

Many projects are large enough that they cannot be completed in 1 year or for other reasons are funded in phases over 2 or more years. Such projects have normally had their emissions benefits reported in their first year of funding (which is, in fact preferable, to avoid any possibility of double-counting). In subsequent years, they may not have their emission reductions re-reported. However, they are eligible for continued funding to accomplish their purposes. Thus, each year a number of projects are funded without having a new listing of emissions benefits.

Table 3 (below) provides an overview of the project benefit analyses submitted by the States according to category of proposal. As indicated in Table 3, a majority of proposals submitted for CMAQ funding have been reviewed for emissions reductions for smog-related pollutants (e.g., CO, VOC and NOx emissions).

Table 3 - FY99 Project Types and Emissions Benefits Calculations
Proposal Category Number of Proposals Funded Proposals with Emissions Benefits Reported Percent with Benefits Reported
Transit24618374%
Traffic Flow40130075%
Shared Ride987676%
Other TCM & I/M925459%
Ped/Bike825871%
Demand Management684363%
Total98771472%

As shown in Figures 3 through 6, the majority of proposals submitted under the CMAQ program have less than 5 kg/day emission reduction potential based on estimates provided by States in their annual CMAQ reports. Approximately half of VOC emission estimates provided by States (331 of 649 reporting VOC emissions reductions), yield 5 kg/day or less, and 91 percent yield less than 100 kg/day. However (as shown in Figure 4) a substantial number of CMAQ-funded proposals submitted with emission estimates for CO (23 percent) target emissions reductions in the 100 to 1000 kg/day emissions range, due primarily to the larger amount of CO emitted from the tailpipe relative to VOC or NOx emissions.

FIGURE 3 - Expected VOC Emissions Reductions (FY 1999)

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FIGURE 4 - Expected CO Emission Reductions (FY 1999)

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FIGURE 5 - Expected NOx Emission Reductions (FY 1999)

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FIGURE 6 - Expected PM-10 Emission Reductions (FY 1999)

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A summary (Table 4) provides an overview of the four major transportation-related pollutants in terms of the number of analyses, as well as minimum, maximum, and median ranges of emission reduction estimates provided by States in their FY 1999 annual reports. The range of minimum, maximum, and median emissions estimates are consistent with those estimates reported in previous CMAQ annual reports.

Table 4 - Estimated CMAQ Air Quality Emission Benefits for Transportation Pollutants (in kg per day)
Emission Type Number1 Minimum Median2 Maximum
VOC653-3540,814
CO345-4308,111
NOx575-93337,113
PM-1052033,758
Total Estimates1,625
NOTES:
1The number of projects submitted with VOC, CO, PM-10 and/or NOx emissions analysis respectively.
2The median, rather than the mean, is a better representation of average effectiveness because the mean is unduly influenced by relatively few projects with large emissions reductions. The median is the point above or below which 50 percent of all observations lie when ranked highest to lowest. Emissions reductions are provided without comment as to their accuracy.

Table 5 (below) provides VOC emission information gathered from State CMAQ annual reports that suggests that the greatest median air quality emissions reductions occur in the demand management category. The lowest level of benefits reported is in the pedestrian/bicycle category. However, the emission reductions of these projects is comparable to others on average, and these are also the least expensive projects reported. Out of the 653 CMAQ proposals submitted with VOC emission reductions estimates, the traffic flow improvement category has the largest single share of projects (285) with quantitative estimates (median value of 4 kg/day VOC emissions removed from the atmosphere). The largest amount of VOC emissions reductions are associated with the "Other TCMs" category (e.g., enhanced I/M programs, etc.) as noted in previous CMAQ annual reports.

Table 5 - Air Quality Analysis by Project Type (VOC, kg/day)
Type of Project Number1 Minimum Median Maximum
Transit173-341,403
Traffic Flow285051,423
Shared Ride7207972
Other TCMs340440,814
Ped/Bike4803481
Demand Mgmt41127529
Total653
NOTES:
1The number of projects submitted with VOC emissions analysis respectively.

Table 6 (below) shows the emissions benefits of 345 CMAQ-funded proposals in kg/day of CO removed from the atmosphere. The category of demand management is shown to have the highest median value for CO (202 kg/day) significantly higher than the median estimates of CO reductions for other categories.

Table 6 - Air Quality Analysis by Project Type (CO, kg/day)
Type of Project Number1 Minimum Median Maximum
Transit90-4308,101
Traffic Flow1380198,111
Shared Ride350497,599
Other TCMs281301,100
Ped/Bike26020217
Demand Mgmt2822023,701
Total345
NOTES:
1The number of projects submitted with CO emissions analysis respectively.

Table 7 (below) shows the minimum, median, and maximum emissions benefits for NOx based on data provided by States in their FY 1999 annual reports. Out of 575 CMAQ proposals submitted with NOx emissions reductions estimates, the category of projects with the most NOx emissions reductions estimates is again shown to be traffic flow improvements.

Table 7 - Air Quality Analysis by Project Type (NOx, kg/day)
Type of Project Number1 Minimum Median Maximum
Transit162-2051,390
Traffic Flow235-931790
Shared Ride71-3102,149
Other TCMs330537,113
Ped/Bike4003472
Demand Mgmt34-2020868
Total575
NOTES:
1The number of projects submitted with NOx emissions analysis respectively.

However, the highest median value of NOx emission reductions potential (20 kg/day) is again shown to be in the demand management category. In fact, the demand management category accounted for the highest median values in all three pollutant types shown in Tables 5-7, although the number of projects in this category is small compared to the others.

Table 8 (below) shows the emissions benefits of 52 CMAQ-funded proposals in kg/day of PM-10 removed from the atmosphere. The category of demand management is shown to have the highest median value for PM-10 (406 kg/day), but this should be discounted heavily since there was only one demand management project with a PM-10 estimate.

Table 8 - Air Quality Analysis by Project Type (PM-10, kg/day)
Type of Project Number1 Minimum Median Maximum
Transit1702232
Traffic Flow3001
Shared Ride6115486
Other TCMs1811233,758
Ped/Bike700140
Demand Mgmt1406406406
TOTAL52
NOTES:
1The number of projects submitted with PM-10 emissions analysis respectively.

Table 9 (below) summarizes the top CMAQ-funded proposals with at least 500 kg/day VOC emission reduction potential based on data provided by States in their annual reports. As shown in this table the two projects resulting in the greatest VOC reductions were the same as reported in the FY 1998 report, which were related to enhanced I/M programs. The total number of CMAQ-funded proposals with at least 500 kg/day VOC emission reductions was found to be 13 for 1999, up one from FY 1998 and down three from FY 1997.

Table 9 - Projects With At Least 500 kg/day VOC Emission Reductions
(Emission reductions are provided without comment on their accuracy.)
Project Description Project Type State Emissions Benefits(kg/day)
Statewide Enhanced Vehicle Inspection and Maintenance programsI/M and Other TCMsNew Jersey40,814
FY 1999 Enhanced Emissions Testing ProgramI/M and Other TCMsConnecticut33,303
Maintenance and Engineering for traffic operations center - Oakland countyTraffic Flow ImprovementsMichigan1,423
Detroit-SEMCOG Nonattainment Area Ozone Action ProgramTransitMichigan1,403
TANK-Clean Air FareTransitKentucky1,343
Metro pool Rideshare ProgramsShared RideNew York972
TARC-Ozone Buster FaresTransitKentucky958
Tampa Traffic Signal ControlTraffic Flow ImprovementsFlorida575
Bi-State Development Agency Bus ReplacementTransitMissouri573
Los Angeles County - Light Rail-Red LineTransitCalifornia568
MTA Harlem Third TrackTransitNew York560
Advanced Transportation Management System Design Group ITraffic Flow ImprovementsFlorida548
Regional Center Signal System - Marion CountyTraffic Flow ImprovementsIndiana548

Areas Needing Improvement

Based on review of the State annual reports submitted for FY 1999, the following areas will need additional improvement as the CMAQ program evolves throughout its existence under the TEA-21. As found in previous reviews of State annual reports, additional efforts to provide more than minimal project descriptions would assist FHWA and FTA in the future. In some cases, project descriptions were found to be inadequate, and thus required follow up phone conversations to State and local officials to better identify the CMAQ projects and their potential air quality benefits. Also, the estimates of emissions benefits that were used to determine CMAQ eligibility for the projects should be submitted in the State reports.

This information is gathered to respond to Congressional inquiries and to support briefings to higher ranking Administration officials, and other major stakeholders which are routinely performed by FHWA/FTA. The basis for information provided is often derived from annual CMAQ reports submitted by States.

Updated: 07/06/2011
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