1 

 

Environmental Systems Products, Inc. 

2002 N. Forbes Blvd. 

Tucson, AZ 85745

The Colorado Remote Sensing Program 

January – December 2009

July 2010 

Prepared for: 

The Colorado Department of Public Health and 

Environment 

Prepared by: 

Peter M McClintock, Ph.D. 

Applied Analysis 

891 Tiburon Blvd. 

Tiburon CA 94920

peter.mcclintock@att.net
2 

Acknowledgments 

The author wishes to acknowledge the support and input given by a number of individuals and 

organizations. Particular thanks are extended to the following contributors: 

CDPHE for providing many helpful comments and suggestions. 

Rodney Johnson and Drew Rau, ESP Program Operations Division and the Remote Sensing 

unit of ESP, Tucson for providing data access and operational information. 

 
3 

Table of Contents 

I. SUMMARY .................................................................................................................................................... 5

II. DESCRIPTION OF THE DENVER CLEAN SCREENING PROGRAM ........................................... 7

A. GENERAL .................................................................................................................................................. 7

1. I/M Program Overview ............................................................................................................................ 7

2. Contractor ................................................................................................................................................ 9

3. Description of RSD .................................................................................................................................. 9

B. MEASUREMENT SITES ............................................................................................................................. 15

1. Description of Sample Site Characteristics ........................................................................................... 15

C. SOURCES OF DATA AND DESCRIPTION OF ELEMENTS ............................................................................. 20

III. SUMMARY OF DATA COLLECTION ................................................................................................ 22

A. MONTHLY COLLECTION ACTIVITY ......................................................................................................... 22

B. MEASUREMENTS BY HOUR OF DAY ........................................................................................................ 22

C. COMPOSITION OF VEHICLES MEASURED ................................................................................................. 23

IV. CLEAN SCREENING PROGRAM PERFORMANCE ....................................................................... 26

A. VEHICLES SELECTED, NOTICES AND REDEMPTIONS ............................................................................... 26

B. CLEAN SCREEN PROGRAM EFFECTIVENESS ............................................................................................ 28

1. Pass / Fail Statistics ............................................................................................................................... 28

2. Tailpipe Emissions ................................................................................................................................. 30

C. GAS CAP EVAPORATIVE EMISSIONS ....................................................................................................... 33

D. HYBRID RSD-LEI VS. 2-HIT RSD ........................................................................................................... 36

V. ESTIMATE OF OVERALL I/M PROGRAM BENEFITS AND CLEAN SCREEN IMPACT ....... 39

A. CONVERSION OF IDLE TESTS TO IM240 EQUIVALENT EMISSIONS ........................................................... 39

B. ANNUAL MILEAGE WEIGHTING .............................................................................................................. 43

C. ANNUAL EMISSIONS REDUCTIONS .......................................................................................................... 44

VI. PROPOSED ADJUSTMENTS TO CLEAN SCREEN STANDARDS ............................................... 46

VII. IM240 PROJECTED EMISSIONS BY MODEL YEAR ..................................................................... 47

REFERENCES 

APPENDICES 

 A1 COLORADO 2008 TRANSIENT TEST EMISSIONS REDUCTIONS 

 A2 COLORADO 2008 CLEAN SCREEN AUDIT TRANSIENT TEST EMISSION REDUCTIONS 

 B COLORADO 2008 TRANSIENT TEST REDUCTION TONS 
4 

List of Tables 

TABLE II-1 COLORADO SPRINGS AND NORTHERN FRONT RANGE RSD SITES ....................................................... 16

TABLE II-2 DENVER RSD SITES............................................................................................................................. 17

TABLE II-3 VEHICLE MEASUREMENT INFORMATION ............................................................................................. 20

TABLE III-1 COLLECTION SUMMARY ...................................................................................................................... 22

TABLE III-2 SOURCE OF VEHICLE REGISTRATIONS MEASURED BY RSD .............................................................. 24

TABLE III-3 REGISTERED JURISDICTION AND AGE OF VEHICLES MEASURED BY RSD ........................................... 25

TABLE IV-1 VEHICLES QUALIFIED AS MEETING CLEAN SCREENING CRITERIA BY STATUS ................................... 28

TABLE IV-2 NOTIFICATIONS TRANSMITTED TO DOR ............................................................................................. 29

TABLE IV-3 CLEAN SCREEN AUDIT TEST PASS / FAIL STATISTICS ........................................................................ 29

TABLE IV-5 TRANSIENT TEST EMISSION REDUCTIONS FOR 1982-1985 PASSENGER VEHICLES ............................. 32

TABLE IV-6 CLEAN SCREEN EMISSIONS IMPACT FOR TAILPIPE EMISSIONS ........................................................... 33

TABLE IV-7 CLEAN SCREEN IMPACT ON EVAPORATIVE HC EMISSIONS ................................................................ 35

TABLE IV-8 GAS CAP RELATED BENEFIT TONS..................................................................................................... 35

TABLE IV-9 AVERAGE EMISSIONS PER VEHICLE ................................................................................................... 37

TABLE V-1 LOW SPEED IDLE TO IM240 ................................................................................................................. 40

TABLE V-2 LOW SPEED IDLE TO IM240 ................................................................................................................. 41

TABLE V-3 ESTIMATED ANNUAL MILEAGE IN 2009 ............................................................................................... 43

TABLE V-4 ESTIMATED ANNUAL TONS OF REDUCTION (IM240 AND IDLE TESTED VEHICLES .............................. 45

List of Figures 

FIGURE I-1 AVERAGE IM240 EMISSIONS REDUCTIONS ............................................................................................ 6

FIGURE II-1: TAGEDITTM SCREEN ........................................................................................................................... 14

FIGURE II-2 A: SITE LOCATIONS NORTHERN FRONT RANGE ................................................................................... 18

FIGURE II-2 B: SITE LOCATIONS – DENVER METRO AREA ...................................................................................... 19

FIGURE III-1 MONTHLY RSD MEASUREMENTS ...................................................................................................... 23

FIGURE III-2 MEASUREMENTS BY TIME OF DAY ................................................................................................... 23

FIGURE IV-7 GAS CAP PRESSURE FAILURE RATES ................................................................................................ 34

FIGURE IV-2 AVERAGE INITIAL IM240 EMISSIONS ................................................................................................ 37

FIGURE IV-3 AVERAGE IM240 EMISSIONS REDUCTIONS ....................................................................................... 38

FIGURE V-1 RSD VS. IDLE TEST EMISSIONS .......................................................................................................... 40

FIGURE V-2 RSD VS. 2500 IDLE TEST EMISSIONS ................................................................................................. 41

FIGURE V-3 RSD VS. 2500 IDLE TEST EMISSIONS ................................................................................................. 42

FIGURE VII-1 LDGV HC REDUCTIONS AND REMAINING EMISSIONS .................................................................... 48

FIGURE VII-2 LDGT HC REDUCTIONS AND REMAINING EMISSIONS ..................................................................... 48

FIGURE VII-3 LDGV CO REDUCTIONS AND REMAINING EMISSIONS .................................................................... 49

FIGURE VII-4 LDGT CO REDUCTIONS AND REMAINING EMISSIONS ..................................................................... 49

FIGURE VII-5 LDGV NOX REDUCTIONS AND REMAINING EMISSIONS .................................................................. 50

FIGURE VII-6 LDGT NOX REDUCTIONS AND REMAINING EMISSIONS .................................................................. 50
5 

I. Summary 

The Colorado Department of Public Health & Environment (CDPHE) and the Department of 

Revenue (DOR) have operated an Enhanced I/M program in the Denver metropolitan area 

since 1995. Operations for a remote sensing clean screening element commenced in 2003. 

Previous reports, “The Colorado Clean Screening Program’ reports for July 2003 – December 

2004 and annual reports for 2005-20081 described on-road measurement activities and the 

vehicles exempted from inspection. This report covers calendar year 2009. 

The clean screening program uses remote sensing to measure the tailpipe emissions of 

vehicles as they drive by measuring equipment positioned on the side of the road. Vehicles 

that are determined to have low tailpipe emissions are granted an exemption from the I/M 

inspection. Clean screening improves the convenience of the I/M program for vehicle 

owners. 

In order to exempt vehicles from inspection, it was necessary to develop computer systems 

and procedures for administering the program and notifying vehicle owners of their inspection 

exemption. These were put in place in 2004. The I/M program is registration enforced; 

therefore the administration of the clean screening program requires the transmission of 

information among the contractor, CDPHE and DOR who manage motor vehicle 

registrations. 

Collection Activity 

In 2009, eighteen RSD 4000 series vans were deployed. Twenty-three different RSD systems 

were used as some units were rotated for preventive or corrective maintenance. Van’s 

deployed at 59 locations in the Denver area, 2 sites in the Northern Front Ranges and 4 sites 

in Colorado Springs for a total of 23,000 active collection hours. Over eight million emission 

measurements were collected and successfully matched to Colorado registered vehicles. 

Additional remote sensing productivity information is provided in Section IV. 

Vehicle Exemptions 

More than 236,000 vehicles met the clean screening criteria and their owners were issued 

notices granting exemption from the I/M test at an inspection station. 

Two methods were used to qualify vehicles, 2-RSD and Hybrid. With the 2-RSD method, 

vehicles qualified for an exemption if they had two or more on-road measurements and the 

most recent two measurements both showed emissions within the clean screen standards. 

With the ‘Hybrid’ clean screening method vehicles measured once by remote sensing 

qualified for clean screening if the emissions measurement was within the clean screen 

standards and the vehicle model had a historically low rate of emissions problems. 

A 2% random sample of vehicles that qualified were not issued exemption notices and 4,103 

of these vehicles were subsequently inspected at an enhanced inspection station. The results 

of the station inspections were used to evaluate the effectiveness of the program. Additional 

information about vehicles mailed notices is provided in Section IV. 

Clean Screen Program Effectiveness 

In a Clean Screen program, some of the vehicles passing the clean screen gas criteria might 

have failed if inspected at an inspection station. Therefore, it is expected that a Clean Screen 
6 

program, while greatly improving convenience for vehicle owners, would reduce the overall 

effectiveness of an I/M program. 

On May 5th 2008, IM240 station test standards were tightened – especially for HC and NOx. 

In December 2008, and periodically during 2009, the LEI table was updated with recent 

IM240 results. The RSD screen standards, however, remained unchanged and a NOx cutpoint 

had not yet been introduced. As a consequence, in 2009 the Hybrid RSD-LEI method 

performed better than the 2-RSD method. Figure I-1 compares the average IM240 exhaust 

reductions per vehicle for normal vehicles inspected at stations to the 2-RSD audit sample and 

the Hybrid RSD-LEI audit sample emissions reductions. For all pollutants the RSD-LEI audit 

sample showed the smallest reductions meaning that the impact of exempting these vehicles 

was the smallest. 

Figure I-1 Average IM240 Emissions Reductions 

In 2009, based on the IM240 test results of 4,000 random audit vehicles, it is projected that 

98.6%, 98.1% and 92.9% of HC, CO and NOx of program exhaust emission reductions were 

retained. The impact on gas cap related evaporative emissions was projected to be another 

4.0% of HC reductions. Clean screen program performance in 2009 showed improvement 

over 2008. 

The methodology for estimating clean screen effectiveness only allows for a score of 100% or 

less and uses the IM240 test as a “gold’ standard. Any variations in vehicle performance or 

the IM240 test procedure that produce an anomalous IM240 test failure are scored against 

Clean Screen. Therefore, it is possible the Clean Screen effectiveness is greater than 

projected. 

0.00

0.02

0.04

0.06

0.08

0.10

0.12

Station

RSD-2

RSDLEI

g/mi

HC

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Station

RSD-2

RSDLEI

CO

0.00

0.02

0.04

0.06

0.08

0.10

Station

RSD-2

RSDLEI

NOx
7 

II. Description of the Denver Clean Screening Program 

A. General 

1. I/M Program Overview 

The Colorado Department of Public Health & Environment (CDPHE) operates an enhanced 

I/M program in the Denver metropolitan area. The clean screening program uses remote 

sensing equipment to measure the tailpipe emissions of vehicles as they drive by the 

measuring equipment. Vehicles that are determined to have low tailpipe emissions are granted 

an exemption from I/M inspection. 

Operating rules for the Clean Screening program are contained in CDPHE Regulation 11. 

The Regulation defines the maximum percentages of vehicles that may be evaluated by the 

clean screen program in the enhanced I/M area: 

In 2006, the percentage of vehicles allowed to be evaluated using remote sensing was 

decreased from 80% to 50% as part of an Early Action Compact (EAC) to achieve an earlier 

attainment designation for ozone. Clean Screening regulations were expanded to allow use of 

a single RSD measurement combined with an index of low emitting model vehicles to 

evaluate exemption candidates 

Excerpt from Colorado Regulation 11 Part A (last update 1/30/09)

II. DEFINITIONS 

16. “Clean Screened Vehicle” is a vehicle that is eligible for inspection, has at least two consecutive 

passing remote sensing emissions readings performed on different days or at different 

approved Clean Screen Inspection Sites prior to its registration renewal date, or for vehicles 

identified as low emitters on the low emitting vehicle index, one passing remote sensing 

reading prior to its registration date, and has otherwise complied with the provisions of section 

IV of this Part A, section XII of Part C and section VI of Part F. 

Although this language is in Reg. 11, the SIP restricts clean screen observations to 50% as mentioned above. 

This could confuse some people. 

 

Regulation 11 established a fee collection system for the clean screen program in the 

enhanced area: 

Excerpt from Colorado Regulation 11 Part A (last update 1/30/09) 

IV.E.2. Beginning with motor vehicle registration renewals coming due in April 2003, 

the clerks and recorders for the counties of Adams, Arapahoe, Boulder, 

Broomfield, Denver, Douglas, and Jefferson shall collect an emissions 

inspection fee in the amount specified pursuant to Section42-3-304(19)(a)(I), 

C.R.S. at the time of registration of a motor vehicle that the Department of 

Revenue has determined to have been clean screened, unless a valid 

certification of emissions compliance has already been issued for the vehicle 

being registered indicating that the vehicle passed the applicable emissions 

test at an enhanced inspection center, motor vehicle dealer test facility or fleet 

inspection station. 
8 

This Section IV.E.2. shall not apply until the Colorado Department of Revenue and the 

Air Pollution Control Division determine that: 

I. All requisite computer-programming changes necessary for the functioning 

of the pay-upon-registration system have been completed; 

II. The test equipment is in place and its reliability has been verified; and 

III. A test run demonstrates that the system will accurately send notices to the 

correct vehicles. 

Regulation 11 establishes requirements for Clean Screen Emissions Inspectors: 

Excerpt from Colorado Regulation 11 Part D (last update 1/30/09) 

V. QUALIFICATION OF CLEAN SCREEN EMISSIONS INSPECTORS 

V.A. Clean Screen Emissions Inspector applicants shall apply for letters of qualification on 

forms provided by the Division. The Division shall issue letters of qualification to 

applicants who comply with the requirements of this section V. The Division will notify 

applicants of the evaluation requirements specified in subsection B. below prior to 

testing. 

V.B. An applicant for a letter of qualification or requalification must demonstrate knowledge, 

skill, and competence concerning the operation of Clean Screen emissions 

inspections. Such knowledge, skill and competence will be demonstrated on actual 

Clean Screen equipment and by passing a skills proficiency qualification test 

including, but not limited to, knowledge of the following: 

V.B.1. Operation of and proper use, care, maintenance, calibration and gas span 

checking of the Division-approved Clean Screen Test Analyzer System. 

V.B.2. Safety procedures for the Clean Screen Inspection Site. 

V.B.3. Proper setup and breakdown of the Clean Screen equipment 

Regulation 11 establishes the criteria vehicles must meet to obtain a Certificate of Emissions 

Control through the Clean Screen Program: 

Excerpt from Colorado Regulation 11 Part C (last update 1/30/09) 

Part C XII. CLEAN SCREEN INSPECTION PROGRAM PROCEDURES 

XII.A. Eligibility to participate 

XII.A.1. Vehicles specified in Part A, Section IV.B., are eligible for participation in the 

Clean Screen Program. 

XII.E.2. The most recent two consecutive emissions readings were observed within 

twelve months of the registration renewal date provided that the most recent 
9 

passing emissions reading must have occurred on a different day or at a 

different site location from the prior reading. 

XII.E.3. No non-complying emissions readings are observed between or subsequent 

to the last pair of complying readings. 

XII.E.4. For vehicles that are identified as low emitters on the low emitting index the 

most recent emission reading was observed within 12-months of the 

registration renewal date. For these vehicles, identification as a low emitter on 

the low emitting vehicle index shall take the place of the second remote 

sensing reading otherwise required under Section XII.E.2., above. 

Excerpt from Colorado Regulation 11 Part F (last update 1/30/09) 

VI. CLEAN SCREEN PROGRAM MAXIMUM ALLOWABLE EMISSIONS LIMITS 

VI.A. In order to obtain a Certificate of Emissions Control through the Clean Screen Program, 

vehicles must not exceed maximum emissions concentrations of 0.50 percent carbon 

monoxide (CO) and 200 parts per million hydrocarbon (HC) as reflected in remote 

sensing emissions readings. 

VI.B. Vehicle owners who participate in the Clean Screen Program shall not be subject to the 

provisions of this Part F other than this section VI. 

VI.B.1. On or before July 1st 

of each year the Air Pollution Control Division shall 

develop a low emitting vehicle index based on a tabulation of the previous 

calendar year’s IM240 inspection program results for specified make, model 

and model year of vehicles. 

VI.B.2. A 98% passing rate for exhaust emissions shall be set as the minimum 

allowable passing criteria for the low emitting vehicle index. 

VI.B.3. In developing the low emitting vehicle index, the Division may use passing 

criteria greater than 98% if necessary to ensure that the use of the low 

emitting vehicle index is equivalent to or better than the use of a second 

remote sensing measurement in terms of air quality benefits. 

2. Contractor 

Environmental Systems Products was contracted to operate the enhanced program by a 

competitive bid process and the contract was subsequently amended to include clean 

screening in the Denver area. Headquartered in Tucson, Arizona, the Remote Sensing 

division of ESP is the largest provider of on-road remote sensing services. ESP uses 

technology derived from that originally developed at Denver University with whom ESP has a 

royalty agreement. 

3. Description of RSD 

Theory of operation 

The RSD is a system designed for a non-intrusive measurement of vehicle emissions. It 

generates and monitors a non-dispersive infrared and ultra-violet beam emitted and reflected 
10 

approximately 10 to 18 inches above ground preferably across a single lane road. Gasoline, 

diesel, or other fossil fuel powered vehicles drive through this beam and the exhaust interferes 

with this transmission of the beam. Quantifying the interference enables the calculation of 

tailpipe concentrations of CO, HC, CO2, NO and particulate matter. A camera 

simultaneously captures a digitized video image of the rear of the vehicle and its license plate. 

Equipment 

The equipment initially deployed in the Northern Front Range counties were RSD-3000 

mobile units also called AccuScanTM. Successor RSD 4000 units were introduced in 2003. 

Both systems are based on a technical platform developed at the University of Denver by Dr. 

Donald Stedman. In 2007, additional RSD4600 units were added. The RSD4600 is very 

similar to the RSD4000-L3 system described below. The RSD4600 has a more compact 

speed and acceleration measurement bar and more diagnostic ports. Functionally, the two 

systems are the same. 

The following elements comprise a complete RSD4000 unit: 

 RSD4000-L3 4-gas analyzer Source Detector Module 

 Corner Cubed Mirror Module (CCM) 

 Two Alignment stands, one each for SDM and CCM 

 Speed/Acceleration subsystem consisting of: 

 Two Speed/Acceleration bars: one emitter and one detector bar with 

adjunct hardware 

 Speed/Acceleration computer 

 Two spare rechargeable battery packs 

 Battery charger 

 Digital Video camera and speed subsystem 

 Computer control console subsystem consisting of: 

 Video monitor 

 PentiumTM–based PC 

 Additional PC cards and internal hardware PC cards: 

 Hard drive 

 Removable Mass Storage 

 Matrox video 

 Serial and COM port 

 RSD4000-L3 operation (data collection) software 

 RSD4000-L3 compatible license plate tag-editing software 
11 

 Calibration subsystem consisting of: 

 Calibration tube 

 Calibration gas bottle 

 Pressure regulator 

 Hoses with quick disconnects 

 RSD4000-L3 shipping container for SDM, TMM, quick disconnect and on/off 

switch fuse 

The following elements comprise an upgraded AccuScanTM van: 

 Ford one-ton truck 

 Triton V-8 engine with 4-speed automatic transmission 

 12 – 14 foot box on bed of truck 

 Roof-mounted 13,500 BTU Coleman air-conditioner 

 5 kW Onan generator 

 Easy access side door 

 Connector panel for quick connection of external cables and cal gas 

hoses 

The RSD unit takes multiple rapid readings for each vehicle to characterize the exhaust plume 

profile and evaluate whether a valid measurement of a vehicle’s exhaust has been achieved. 

The criteria include how much vehicle exhaust plume is available for the duration of the 

sampling period, evaluation of whether plume measurements are consistent with normal 

plume dissipation, and correction for changes in background concentrations of emissions. 

The RSD4000 units meet the following performance criteria: 

○ AccuScan measures the exhaust of a passing motor vehicle in less than 0.7 seconds. 

Non-dispersive infrared (IR) spectroscopy, the same analytical technique used in 

garage based two-speed idle and ASM equipment is used to measure concentrations of 

CO, HC, and CO2. Dispersive ultraviolet (UV) spectroscopy is used to measure NOx. 

The system is based on the original designs and patents of Dr. Donald Stedman, 

professor emeritus at the University of Denver. 

○ CDPHE has adapted BAR performance specifications for remote sensing technology. 

ESP previously provided an audit gas vehicle pursuant to the BAR OREMS 

specifications. As such, ESP asserts the AccuScanTM RSD4000, which has previously 

and consistently met BAR detector accuracy specifications, will meet the Colorado 

RSD specifications. 
12 

○ Detector accuracy that meets the California BAR OREMS Specification:1

o OREMS detector accuracy, including speed and acceleration, shall meet or exceed 

97% (i.e., 39/40 runs for each gas within limits) during controlled testing. 

o OREMS detector accuracy, including speed and acceleration, shall meet or exceed 

90% (i.e., 36/40 runs for each gas within limits) during routine daily on-road testing. 

1. The carbon monoxide (CO %) reading shall be within  10% of the 

Certified Gas Sample, or an absolute value of  0.25% CO 

(whichever is greater), for a gas range less than or equal to 3.00% 

CO. Negative values shall be included and shall not be rounded to 

zero. 

The CO % reading shall be within  15% of the Certified Gas 

Sample for a gas range greater than 3.00% CO. Negative values shall 

be included and shall not be rounded to zero. 

2. The hydrocarbon recorded in (HC ppm hexane) reading shall be 

within  15% of the Certified Gas Sample, or an absolute value of 

250 ppm HC, (whichever is greater). Negative values shall be 

included and shall not be rounded to zero. 

3. The nitric oxide (NO ppm) reading shall be within  15% of the 

Certified Gas Sample, or an absolute value of  250 ppm NO, 

(whichever is greater). Negative values shall be included and shall 

not be rounded to zero. 

4. Since any gasoline combustion engine should not exceed certain 

theoretical emission levels, contractors shall not submit readings 

outside the following limits: CO + CO2  21.0 %, HC  35,000 ppm 

hexane, CO2  16.0 %, and NO  7000 ppm. 

5. The vehicle speed measurement shall be accurately recorded within 

 1.0 mile per hour. 

6. The vehicle acceleration measurement shall be accurately recorded 

within  0.5 mile per hour / second. 

 

1

 On Road Emissions Measurement System OREMS) Specifications, Revision L, Bureau of Automotive Repair, Engineering 

and Technical Research Branch, 10240 Systems Parkway, Sacramento, CA 95827; 2001 California DCA/BAR; p. 5. 
13 

Vehicle Identification 

The system captures emissions readings and rear pictures of vehicles that pass through the 

RSD infrared beam. The video and emissions readings taken are stored directly on a 

removable media disk and can be used for future reference. 

ESP’s TagEditTM software is used to transcribe vehicle license plate information. Figure II-1 

below shows an example of a TagEditTM screen. This license plate editing service is superior 

to an automatic license plate reader because: 

 All video images associated with valid emissions data get processed. This ensures the 

highest possible vehicle capture rate. 

 Vehicles with special plates are also processed. This is especially important in areas 

where many unique license plates are issued. Failure to process all plate types can create 

a statistically skewed database that could be misinterpreted by the public as “targeting” 

only certain vehicle classes. 
14 

Figure II-1: TagEditTM Screen 

A special registration database was created for the Clean Screen program to allow vehicles to 

be identified (VINs) from Clean Screen license photos captured days prior to their data 

processing. A system adding a TXID was instituted by the DOR to allow their system to 

provide up-to-date data and a vehicle history. This Clean Screen registration database is 

updated nightly with all the changes statewide that affect what VIN is associated with what 

plate. A lag time interval is incorporated to allow time for updates to get from the County 

Clerks Offices to the DOR database. The separate Clean Screen Registration Database on the 

ESP Arvada host contains all vehicle registration records statewide, even though only certain 

counties are expected to participate in the Clean Screen program. The future growth of 

registration could require some housekeeping, but there is plenty of hardware scalability to 

handle this growth. 
15 

B. Measurement Sites 

1. Description of Sample Site Characteristics 

Good remote sensing sites are critical for obtaining RSD measurements that are representative 

of vehicle operation. Recommended site attributes include: 

(1) Absence of cold start vehicle operating conditions 

(2) Sites where vehicles will generally be accelerating or driving at a steady speed 

uphill to ensure adequate engine power and exhaust plumes and avoid the problem of 

RSD not measuring vehicles that have virtually no exhaust under deceleration 

(3) Absence of enrichment due to high load conditions 

(4) Single lane operation 

(5) High volume traffic 

(6) Unobtrusive citing of the remote sensing equipment 

(7) Adequate median space for safe operation of the RSD equipment. 

Sites must also meet requirements of Regulation 11: 

Excerpt from Colorado Regulation 11 (last update 10/18/2007) 

IV. REQUIREMENTS FOR CLEAN SCREEN/REMOTE SENSING SITES 

IV.A. Applicability 

Clean Screen Inspection Sites must meet all applicable standards pursuant to this Part D and 

the Department of Revenue's regulations in order to qualify for operating in Colorado's Clean 

Screen Program. 

IV.B. Standards for emissions inspection sites 

All sites shall comply with all applicable state and local codes/ordinances and maintain 

appropriate permits for that specific municipality and location. 

IV.C. All Clean Screen Sites must provide reasonable access in order for Department of 

Revenue (and if applicable, Division) staff to conduct periodic quality control and audit 

functions as necessary. 

IV.D. Applicants for a license as a Clean Screen Emissions Inspector shall complete forms 

approved by the Department of Revenue which shall include, but not be limited to, a 

declaration of any past violations of AIR Program statute Sections 42-4-301 through 

42-4-316, C.R.S., as amended or any rule or regulation pursuant to such law. 

A small number of measurements were made in Colorado Springs and in the Northern Front 

Range at the sites shown in Table II-1. Table II-2 lists the Denver area site locations used for 

the clean screening program, the number of days each site was used, the total hours during 
16 

which measurements were collected and the number of vehicles measured per hour. The 

hours shown do not include travel time to and from the site, equipment set-up and equipment 

takedown time. 

Denver site locations are illustrated in Figure II-2. Blue sites have been approved for more 

than six months. Green sites are new additions over the last 6 months and Red sites are no 

longer permitted. The X's represent HQ and other stations where RSD vans are housed. 

Table II-1 Colorado Springs and Northern Front Range RSD Sites 

Site 

Code Location City

Active 

Days

Total 

Active 

Hours

Registered 

Vehicles 

Measured

Veh's 

Per 

Hour

2518 ONRAMP TO E.PLATTE AVE FROM NB ACADEMY BLVD COLORADO SPRINGS 3 21 3,318 156 

2519 ONRAMP TO NB I-25 FROM FILLMORE ST COLORADO SPRINGS 8 56 15,332 272 

2520 ONRAMP TO NB I-25 FROM N.ACADEMY BLVD COLORADO SPRINGS 2 12 1,846 158 

2521 ONRAMP TO NB I-25 FROM S.ACADEMY BLVD COLORADO SPRINGS 4 22 4,666 210 

3017 EB TRILBY ROAD EAST OF SHIELDS STREET FORT COLLINS 17 95 24,211 254 

2989 EB US 34 BYPASS FROM 23RD AVE GREELEY 7 43 5,257 121 

Total 41 250 54,630 218
17 

Table II-2 Denver RSD Sites 

Site 

Code Location City

Active 

Days

Total 

Active 

Hours

Registered 

Vehicles 

Measured

Veh's 

Per 

Hour

2808 ONRAMP TO SB I-25 FROM 136TH AVE THORNTON 12 91 19,280 212

2819 ONRAMP TO SB 121 FROM WB 287 WESTMINSTER 33 292 89,722 307

2821 ONRAMP TO NB I-25 FROM 120TH AVE WESTMINSTER 19 127 22,937 181

2967 EB SH-2 JUST NORTH OF QUEBEC PKWY/ROEMARY ST COMMERCE CITY 2 15 1,112 73

2971 EB DILLON RD EAST OF US-287 BROOMFIELD 43 315 85,941 273

8089 ONRAMP TO WB I-76 FROM 96TH AVE COMMERCE CITY 26 183 49,651 272

8090 ONRAMP TO EB I-76 FROM PECOS ST. DENVER 2 13 1,034 79

8091 ONRAMP TO WB I-76 FROM BROMLEY LN. BRIGHTON 8 62 11,704 190

8093 ONRAMP TO WB I-70 FROM NB I-25 DENVER 224 2,576 1,549,220 601

8107 ONRAMP TO WB US-36 FROM BROADWAY DENVER 121 1,227 370,051 302

8115 ONRAMP TO EB I-76 FROM FEDERAL BLVD DENVER 3 14 2,020 143

8129 ONRAMP TO WB I-76 FROM PECOS ST DENVER 6 41 7,656 185

2969 WB DELMAR PKWY AT OSWEGO AURORA 21 161 20,754 129

8095 ONRAMP TO SB I-225 FROM ILLIFF AVE. AURORA 26 167 13,645 82

8098 ONRAMP TO NB I-225 FROM ILLIFF AVE AURORA 26 173 27,022 156

8120 ONRAMP TO SB I-225 FROM ALAMEDA AVE AURORA 1 6 1,015 177

8121 ONRAMP TO SB I-225 FROM MISSISSIPPI AVE AURORA 81 567 159,457 281

2826 ONRAMP TO EB US-36 FROM MCCASLIN LOUISVILLE 6 41 7,854 194

8057 ON-RAMP TO SB SH 157 FROM PEARL ST. BOULDER 64 451 86,849 192

8064 ONRAMP TO NB SH 157 FROM EB TABLE MESA BOULDER 48 352 73,310 209

8079 ONRAMP TO WB US-36 FROM WADSWORTH PKWY BROOMFIELD 191 1,792 629,218 351

2811 ONRAMP TO I-25 FROM WB SPEER DENVER 79 672 258,393 384

2970 EB 48TH AVE EAST OF CHAMBERS RD DENVER 12 90 12,495 138

8062 ONRAMP TO EB I-70 FROM FEDERAL BLVD DENVER 55 560 138,293 247

8097 ONRAMP TO WB US-6TH AVE FROM NB I-25 DENVER 143 958 724,903 757

8122 ONRAMP TO NB I-25 FROM PARK AVE DENVER 77 806 289,815 360

8123 ONRAMP TO NB I-25 FROM 58TH AVE. DENVER 52 425 122,953 289

2167 ONRAMP TO NB I-25 FROM WILCOX ST. CASTLE ROCK 6 44 9,892 224

2320 ONRAMP TO EB C-470 FROM BROADWAY HIGHLANDS RANCH 140 1,071 545,419 509

2322 ONRAMP TO WB C-470 FROM UNIVERSITY BLVD HIGHLANDS RANCH 20 115 17,641 154

2574 ONRAMP TO NB I-25 FROM WB COUNTY LINE RD. HIGHLANDS RANCH 5 41 4,389 106

2576 ONRAMP TO SB I-25 FROM EB COUNTY LINE RD. HIGHLANDS RANCH 44 312 66,540 214

2577 ONRAMP TO NB I-25 FROM EB COUNTY LINE RD. HIGHLANDS RANCH 174 1,366 552,255 404

2807 ONRAMP TO NB I-25 FROM WB LINCOLN AVE LITTLETON 28 197 81,194 413

8063 ONRAMP TO EB C-470 FROM SANTA FE DR HIGHLANDS RANCH 158 1,168 511,081 438

8077 ONRAMP TO EB C-470 FROM QUEBEC ST. HIGHLANDS RANCH 153 1,194 658,158 551

8083 ONRAMP TO SB I-25 FROM FOUNDERS PARKWAY (EXIT 184) CASTLE ROCK 3 26 4,235 166

8084 ONRAMP TO SB I-25 FROM LINCOLN AVE. LITTLETON 9 67 8,651 130

8085 ONRAMP TO NB I-25 FROM WOLFENSBERGER RD. (EXIT 182) CASTLE ROCK 60 392 124,873 319

8086 ONRAMP TO NB I-25 FROM FOUNDERS PARKWAY (EXIT 184) CASTLE ROCK 69 505 178,276 353

2173 ONRAMP TO EB C-470 FOM KEN CARYL AVE. LAKEWOOD 51 420 51,800 123

2175 ONRAMP TO WB C-470 FROM KIPLING ST. LAKEWOOD 51 543 60,791 112

2458 ONRAMP TO WB US-6TH AVE FROM SIMMS ST LAKEWOOD 50 400 116,084 290

2460 ONRAMP TO EB US-6TH AVE FROM SB WADSWORTH BLVD LAKEWOOD 24 215 25,259 117

2461 ONRAMP TO WB US-6TH AVE FROM NB WADSWORTH BLVD LAKEWOOD 9 58 11,055 192

2813 ONRAMP TO NB I-25 FROM COLFAX LAKEWOOD 1 2 570 264

8058 ONRAMP TO WB I-76 FROM SHERIDAN BLVD. ARVADA 99 871 216,359 248

8069 ONRAMP TO WB I-70 FROM KIPLING ST. WHEATRIDGE 55 594 157,586 265

8100 ONRAMP TO WB US-6TH AVE FROM SB KIPLING ST. LAKEWOOD 17 129 29,545 229

8106 ONRAMP TO NB US-285 (HAMPDEN AVE) FROM KIPLING BLVD. DENVER 61 431 130,368 302

8130 ONRAMP TO EB I-76 FROM SHERIDAN BLVD ARVADA 49 441 91,226 207

Total 2,717 22,777 8,429,551 370
18 

Figure II-2 a: Site Locations Northern Front Range 
19 

Figure II-2 b: Site Locations – Denver Metro Area 
20 

C. Sources of Data and Description of Elements 

Data used in the analyses in this report come from three primary sources: 

 Remote sensing unit measurements 

 The DMV database maintained on the AIR program contractor host computer 

 I/M test database maintained on the AIR program contractor host computer 

Data from the RSD units are loaded into a database maintained by the centralized 

contractor, ESP. Using the vehicle plate identified by RSD, the registration file is 

accessed to determine the vehicle identification number (VIN) and vehicle registration 

information. ESP uses the Polk VIN Decoder to add additional information about each 

vehicle. The combined data fields are shown in Table II-3. 

Table II-3 Vehicle Measurement Information 

Field Name Description 

V_DATA_VER Data version 

V_DATE_TIME Date and time of measurement 

V_RSD_UNIT RSD system number 

V_SEQ_NUM Measurement sequence number 

V_SITE_CODE Site reference 

V_PROGRAM_CODE I/M Program 

V_VAN_OPERATOR_ID 

V_CO Carbon monoxide emissions % 

V_CO2 Carbon dioxide emissions % 

V_MAX_CO2 Maximum observed CO2 

V_CO2_VOLUME Volume of CO2 observed 

V_HC Hydrocarbon emissions ppm hexane equivalent 

V_NOX Oxides of nitrogen emissions ppm (NOx) 

V_NOX_FLAG Validity of NOx measurement 

V_OPAC Opacity measurement 

V_SPEED Speed MPH 

V_ACCEL Acceleration MPH/S 

V_SA_UNITS Units of speed and acceleration 

V_TEMPERATURE Ambient temperature 

V_HUMIDITY Ambient humidity 

V_WIND_SPEED Ambient wind speed 

V_WIND_DIRECTION Ambient wind direction 

V_WEATHER_UNITS 

V_PLATE_CONFIDENCE Reserved for future use 

V_ALPR_VENDOR Reserved for future use 

V_TEST_COUNTY Reserved for future use 

V_CRC 

V_TAG_EDIT_MODE 

V_TAG_EDIT_ID_1 

V_TAG_EDIT_ID_2 
21 

Field Name Description 

V_TAG_EDIT_ID_3 

V_TAG_EDIT_EMP_1 

V_TAG_EDIT_EMP_2 

V_TAG_EDIT_EMP_3 

V_PLATE License plate 

V_PLATE_STATE State issuing license plate 

V_PLATE_TYPE Type of plate 

V_VIN Vehicle Identification Number 

V_LZIP Zip code for legal owner address 

V_STATE_MAKE Make code 

V_STATE_MODEL Model code 

V_COUNTY County of registration 

V_VEH_YEAR Model year 

V_EM_FLAG Subject to emissions test 

V_POLK_VEH_YEAR Polk decoded model year 

V_POLK_MAKE Polk decoded make 

V_POLK_VEH_TYPE Polk decoded vehicle type (P-pass, T-truck, U-unknown) 

V_POLK_MODEL Polk decoded model 

V_POLK_DISP Polk decoded engine displacement 

V_VSP Calculated vehicle specific power during measurement 
22 

III. Summary of Data Collection 

Up to 18 remote sensing units were deployed for 2,758 days during the one-year period to 

collect 54,000 measurements in Colorado Springs and the northern Front Range and 

8,429,000 measurements in the enhanced I/M area that have a visible plate and valid HC, 

CO, speed and acceleration values. 

Plates were matched to registrations to determine model and owner information. Almost 

seven million of the measurements were on vehicles registered in the Denver area, 

116,000 measurements were vehicles registered in Colorado Springs and 204,000 in the 

North Front Range. Another 266,000 measurements were of vehicles registered in other 

Colorado counties. 

Clean screen exemption notices were issued to 236,400 Denver vehicles due to renew 

their registration in 2009. These results are summarized in Table III-1 to II-3. 

Table III-1 Collection Summary 

A. Monthly Collection Activity 

Figure III-1 shows the monthly RSD measurements. Data collection increased through 

the year as additional vans were added. Collection rates were lower during winter 

months. 

B. Measurements by Hour of Day 

Figure III-2 ‘Measurements by Hour of Day’ shows the number of vehicles 

measured during each hour of the day. The shape of the curve is indicative of when 

measurements were collected and does not represent the level of traffic during the day. 

Most measurements were collected between 8:00am and 6:00pm. 

Collection Summary

Statistic

Colorado 

Springs & 

NFR Denver Total

Sites Used 6 59 65 

Collection Van Days 41 2,717 2,758 

Active Collection Van Hours 250 22,777 23,027 

Matched to Registration 54,630 8,429,551 8,484,181 

Notices Generated for 2009 renewals 236,400 236,400 
23 

Figure III-1 Monthly RSD Measurements 

Figure III-2 Measurements by Time of Day 

C. Composition of Vehicles Measured 

Table III-2 Source of Vehicle Registrations shows that 2.4% of vehicles measured 

were registered to the North Front Range, 1.4% were registered in El Paso County 

(Colorado Springs), 3.1% were registered in other non-I/M counties, and 12.4% were not 

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000

1,000,000

Jan

FebMar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Measurements

Measurements by Month

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000

1,000,000

Before 6 am

6-7 am7-8 am8-9 am

9-10 am

10-11 am11-12 am

12 -1 pm

1-2 pm2-3 pm3-4 pm4-5 pm5-7 pm6-7 pm7-8 pm

Measurements

Hour

Measurements by Time of Day
24 

matched. Almost 80% of the unmatched plates were classified as unmatched because 

they were matched to more than one vehicle record. This can occur when plates are 

transferred by an owner to a new vehicle. These numbers are indicative of on-road 

activity – not unique registrations. The same vehicle may be measured more than once. 

Table III-3 shows the distribution of vehicle measurements by vehicle type, age 

group and registration jurisdiction. The vehicle types were identified by the Polk VIN 

decoder, which classified 97% of all models. The model years of 1980 and older vehicles 

and some of the newest 2006 through 2009 models were determined from the registration 

information but the vehicle type was not available. These were classified as Unknown in 

Table III-3. Nine hundred measurements of motorcycles were also included as 

Unknown. 

Table III-2 Source of Vehicle Registrations Measured by RSD 

Program County Pass Truck Unknown Total %

Enhanced Adams 405,320 575,660 16,023 997,003 11.8%

Enhanced Arapahoe 443,754 613,558 35,280 1,092,592 12.9%

Enhanced Boulder 182,662 186,395 7,614 376,671 4.4%

Enhanced Broomfield 117,000 132,584 5,429 255,013 3.0%

Enhanced Denver 446,707 584,747 56,675 1,088,129 12.8%

Enhanced Douglas 501,643 853,344 31,602 1,386,589 16.3%

Enhanced Jefferson 667,501 920,673 30,199 1,618,373 19.1%

Enhanced State of Colorado 9,754 18,285 2,027 30,066 0.4%

Subtotal Enhanced 2,774,341 3,885,246 184,849 6,844,436 80.7%

North Front Range Larimer 35,459 42,820 2,414 80,693 1.0%

North Front Range Weld 49,070 71,853 2,822 123,745 1.5%

Subtotal North Front Range 84,529 114,673 5,236 204,438 2.4%

El Paso El Paso 47,044 65,980 3,451 116,475 1.4%

Non I/M 94,346 164,013 7,596 265,955 3.1%

Not Matched 1,052,877 12.4%

Total 4,229,912 3,000,260 201,132 8,484,181 100.0%
25 

Table III-3 Registered Jurisdiction and Age of Vehicles Measured by RSD 

 Vehicle 

Type Model Year Enhanced 

 Northern 

Front 

Range El Paso 

 NonI/M Total 

Pass 1981 & older 879 45 9 48 981 

1982-1985 10,691 591 191 904 12,377 

1986-1990 73,432 3,144 1,306 4,217 82,099 

1991-1995 284,475 10,887 4,968 10,659 310,989 

1996-2000 730,189 22,691 11,814 23,885 788,579 

2001-2005 1,067,774 30,095 18,529 36,100 1,152,498 

2006 & newer 606,901 17,076 10,227 18,533 652,737 

 Light Truck 1981 & older 718 53 21 151 943 

1982-1985 9,107 700 155 1,049 11,011 

1986-1990 53,471 2,464 1,005 4,098 61,038 

1991-1995 228,492 9,149 3,959 11,963 253,563 

1996-2000 871,784 25,452 14,099 37,249 948,584 

2001-2005 1,661,053 45,402 28,630 67,748 1,802,833 

2006 & newer 1,060,621 31,453 18,111 41,755 1,151,940 

Unknown 1981 & older 18,812 1,046 565 2,036 22,459 

1982-1985 378 26 24 76 504 

1986-1990 339 42 23 66 470 

1991-1995 724 68 40 119 951 

1996-2000 2,624 112 74 281 3,091 

2001-2005 3,073 217 177 350 3,817 

2006 & newer 158,551 3,725 2,548 4,668 169,492 

Total 204,438 6,844,088 116,475 265,955 7,430,956 
26 

IV. Clean Screening Program Performance 

A. Vehicles Selected, Notices and Redemptions 

The conditions for a vehicle to obtain a clean screen exemption are defined in Regulation 11. 

Extracts describing the measurements required and the vehicle emission standards to be applied 

are reproduced here for convenience: 

Excerpt from Colorado Regulation 11 Part C (last update 1/30/09) 

XII. CLEAN SCREEN INSPECTION PROGRAM PROCEDURES 

XII.A. Eligibility to participate 

XII.A.1. Vehicles specified in Part A, Section IV.B., are eligible for participation in the 

Clean Screen Program.Regulation No. 11 Page 28 Appendices 

XII.A.2. Clean Screen inspections applicable to the program are those performed within 

twelve months prior to an individual vehicle's registration renewal date. 

XII.A.3. Vehicles are eligible for participation in the Clean Screen Program when the two 

most recent consecutive emissions readings observed during the 12-months 

prior to its registration date comply with the standards specified in Part F (VI) 

and: the most recent passing emissions reading occurred on a different day or at 

a different site location from the prior reading. Additionally, vehicles that are 

identified as low emitters on the low emitting vehicle index are eligible for 

participation in the clean screen program when the most recent emissions 

reading observed during the 12-months prior to their registration date complies 

with the standard specified in Part F, Section VI. 

XII.A.4. The following vehicles are ineligible for participation in the Clean Screen 

Program: 

XII.A.4.a. New Vehicles as specified in Section 42-4-310(b)(II)(A), C.R.S. 

XII.A.4.b. Vehicles involved in a change of ownership. 

XII.A.4.c. Vehicles owned by the United States government or any agency 

thereof or by the State of Colorado or any agency or political subdivision 

thereof, pursuant to Section 42-4-310(l)(b)(I), C.R.S. 

In order to obtain a Certificate of Emissions Control the following conditions must be met: 

XII.E.1. The vehicle emissions levels are the same as or less than the limits specified in 

Part F(VI). 

XII.E.2. The most recent two consecutive emissions readings were observed within 

twelve months of the registration renewal date provided that the most recent 

passing emissions reading must have occurred on a different day or at a different 

site location from the prior reading. 
27 

XII.E.3. No non-complying emissions readings are observed between or subsequent to 

the last pair of complying readings. 

XII.E.4. For vehicles that are identified as low emitters on the low emitting index the most 

recent emission reading was observed within 12-months of the registration 

renewal date. For these vehicles, identification as a low emitter on the low 

emitting vehicle index shall take the place of the second remote sensing reading 

otherwise required under Section XII.E.2., above 

Excerpt from Colorado Regulation 11 Part F (last update 1/30/09) 

VI. CLEAN SCREEN PROGRAM MAXIMUM ALLOWABLE EMISSIONS LIMITS 

VI.A. In order to obtain a Certificate of Emissions Control through the Clean Screen Program, 

vehicles must not exceed maximum emissions concentrations of 0.50 percent carbon 

monoxide (CO) and 200 parts per million hydrocarbon (HC) as reflected in remote 

sensing emissions readings. 

VI.B. Vehicle owners who participate in the Clean Screen Program shall not be subject to the 

provisions of this Part F other than this section VI. 

VI.B.1. On or before July 1st 

of each year the Air Pollution Control Division shall develop a 

low emitting vehicle index based on a tabulation of the previous calendar year’s 

IM240 inspection program results for specified make, model and model year of 

vehicles. 

VI.B.2. A 98% passing rate for exhaust emissions shall be set as the minimum allowable 

passing criteria for the low emitting vehicle index. 

VI.B.3. In developing the low emitting vehicle index, the Division may use passing criteria 

greater than 98% if necessary to ensure that the use of the low emitting vehicle 

index is equivalent to or better than the use of a second remote sensing 

measurement in terms of air quality benefits. 

Table IV-1 summarizes the monthly number of vehicles meeting screening criteria each month, 

the number withheld for the random sample, the number rejected through QA checks, and the 

number notified. 

A random sample of two percent of vehicles meeting Clean Screen criteria are not mailed 

notices. These vehicles are required to go to a test station to obtain the station-based emission 

inspection. This random sample of vehicles is used to evaluate the effectiveness of the Clean 

Screen program. 

Not all vehicles notified for clean screen or withheld in the random sample redeem the clean 

screen or obtain a test at that time, for example vehicles that changed owner are likely to have 

obtained an earlier station inspection. Compared to the 236,400 vehicles notified in 2009, fewer 

vehicles 199,344 (84%) obtained a clean screen. 
28 

Table IV-1 Vehicles Qualified As Meeting Clean Screening Criteria by Status 

 Table IV-2 lists the number of vehicles by month and city that were notified via the Department 

of Revenue. 

B. Clean Screen Program Effectiveness 

The emissions reductions obtained during the station testing of the audit sample vehicles are used 

to project the total emissions reductions foregone as a result of the Clean Screen program. 

1. Pass / Fail Statistics 

Matching initial tests for audit vehicles were limited to those occurring after the second RSD 

measurement and before expiration of the assigned Clean Screen period. Matching tests were 

sought through the end of February 2010. The tests identified for audit sample vehicles and their 

I/M results are tabulated in Table IV-3. As noted earlier, some of the anticipated random vehicles 

did not obtain a test within the Clean Screen period. In aggregate, 1.2% of the tested audit 

vehicles failed their tailpipe emissions inspection, and 3.0% of the tested audit vehicles failed 

their gas cap pressure test2

. 

The 1.2% of emissions failures in 2009 increased from 0.6% in 2007 but lower than the 1.6% 

rate that followed the May 5th, 2008 tightening of IM240 standards1

. The LEI table was updated 

for 2009 but the HC and CO RSD clean screening cutpoints were left unchanged and no RSD 

cutpoint for NOx was introduced. The overall rate of gas cap failures in the program was also 

higher in 2009 than in 2008. 

 

2

 Note that the number of emissions fails plus the number of Gas Cap / Gas Cap Pressure failures does not always equal the total

number of inspection failures. In a few cases a vehicle may fail both Emissions and Gas Cap. In a few cases, vehicles fail for 

other reasons. 

Reg 

Year

Reg 

Month

Random 

Sample QA failed Notified

Total 

Qualified

Random 

% of 

Qualified

2009 Jan 444 341 21,224 22,009 2.0%

2009 Feb 422 461 20,302 21,185 2.0%

2009 Mar 430 345 20,636 21,411 2.0%

2009 Apr 357 291 17,082 17,730 2.0%

2009 May 355 351 16,837 17,543 2.0%

2009 Jun 399 362 18,935 19,696 2.0%

2009 Jul 389 366 18,448 19,203 2.0%

2009 Aug 457 369 21,576 22,402 2.0%

2009 Sep 455 417 22,011 22,883 2.0%

2009 Oct 487 381 23,186 24,054 2.0%

2009 Nov 344 278 16,528 17,150 2.0%

2009 Dec 405 300 19,635 20,340 2.0%

Total 4,944 4,262 236,400 245,606 2.0%
29 

Table IV-2 Notifications Transmitted to DOR 

Table IV-3 Clean Screen Audit Test Pass / Fail Statistics 

Registration Renewal Month

City Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total

DENVER 3,939 3,773 3,878 3,426 3,355 3,905 3,590 4,083 4,242 4,457 3,279 3,811 45,738

AURORA 1,796 1,767 1,811 1,394 1,498 1,565 1,602 1,765 1,842 1,909 1,532 1,750 20,231

LITTLETON 1,548 1,472 1,487 1,208 1,205 1,371 1,332 1,486 1,624 1,788 1,336 1,413 17,270

ARVADA 1,233 1,129 1,200 1,008 979 1,150 959 1,365 1,397 1,464 1,124 1,205 14,213

LAKEWOOD 1,122 1,087 1,129 914 937 1,045 905 1,235 1,283 1,364 1,035 1,119 13,175

CENTENNIAL 986 931 1,001 804 719 846 829 997 978 1,064 822 886 10,863

WESTMINSTER 1,141 1,032 1,102 849 788 958 968 1,078 1,180 1,138 752 1,014 12,000

BOULDER 886 794 759 630 589 711 718 902 881 834 644 670 9,018

HIGHLAND RCH 1,064 1,041 1,076 948 1,000 1,029 1,119 1,128 1,176 1,271 644 1,029 12,525

THORNTON 1,052 969 931 797 757 868 915 1,001 960 967 562 849 10,628

BROOMFIELD 669 702 660 501 574 609 512 759 762 793 561 661 7,763

PARKER 771 794 750 666 648 640 684 731 724 838 493 742 8,481

GOLDEN 518 464 494 381 396 475 408 590 530 607 468 534 5,865

CASTLE ROCK 781 741 740 652 613 686 767 766 810 735 464 560 8,315

ENGLEWOOD 447 467 428 353 366 345 331 436 387 469 344 405 4,778

LONGMONT 333 313 328 252 223 262 312 299 279 309 249 248 3,407

WHEAT RIDGE 229 254 244 185 200 211 197 269 280 319 216 256 2,860

BRIGHTON 284 227 275 195 198 233 239 267 256 267 191 257 2,889

COMMERCE CITY 257 284 265 234 199 236 236 265 260 254 189 223 2,902

LOUISVILLE 207 193 181 167 160 168 192 240 195 201 175 142 2,221

NORTHGLENN 298 277 281 243 238 242 240 300 309 283 149 266 3,126

LAFAYETTE 169 187 172 126 137 172 172 201 195 201 128 134 1,994

EVERGREEN 174 134 167 106 108 130 128 158 170 174 127 182 1,758

MORRISON 127 117 127 91 93 89 99 97 125 127 124 120 1,336

GREENWOOD VLG 193 169 165 149 116 133 132 164 141 194 113 146 1,815

CASTLE PNS N 2 2 1 1 5 7 24 119 92 95 348

SUPERIOR 121 117 121 80 84 95 138 148 115 113 82 110 1,324

CONIFER 45 65 51 45 41 43 35 68 46 80 73 64 656

LONE TREE 123 105 123 96 88 112 89 124 121 130 55 136 1,302

CHERRY HL VLG 73 62 57 60 35 54 35 55 54 66 48 48 647

ERIE 52 61 59 36 37 41 55 46 54 60 48 48 597

FRANKTOWN 55 48 53 43 38 39 65 35 54 50 48 48 576

FEDERAL HTS 58 68 61 38 60 49 66 62 76 66 42 68 714

HENDERSON 73 59 45 36 40 36 40 52 65 35 39 48 568

LARKSPUR 75 64 56 54 62 65 67 57 52 70 36 54 712

SEDALIA 36 58 54 49 43 40 48 50 47 60 36 31 552

EDGEWATER 23 21 36 25 18 24 18 26 26 41 24 35 317

GLENDALE 13 15 17 13 16 20 19 13 25 14 18 15 198

NIWOT 19 15 17 12 12 20 20 14 23 16 14 13 195

OTHER 234 224 233 215 166 218 162 237 243 239 152 200 2,523

Total 21,224 20,302 20,636 17,082 16,837 18,935 18,448 21,576 22,011 23,186 16,528 19,635 236,400

Vehicle Type Vehicles

Fail 

Emissions

Fail Gas 

Cap / 

Pressure

Fail 

Inspection

Passenger 1,803 22 54 74 

Light Truck 2,300 26 70 97 

Total 4,103 48 124 171 

Percentage 1.2% 3.0% 4.2%
30 

Following sections describe in detail how these results are used to evaluate the emissions impact 

of the Clean Screen program. 

2. Tailpipe Emissions 

The vast majority of vehicles were tested using IM240 tailpipe tests and IM240 testing provides 

a more accurate estimate of vehicle emissions than the idle tailpipe test. Therefore, the results of 

the 95% of the clean screen audit sample vehicles tested using IM240 were used to evaluate the 

exhaust emissions effectiveness of the clean screen program. The emission reductions from 

vehicles inspected using the idle test procedure have been included in the overall estimate of 

program benefits. Models inspected using the idle test procedure are 1981-and-older models and 

1982-and-newer trucks over 8500 lbs GWWR plus some four-wheel drive and traction control 

vehicles. 

Vehicle test results were sorted by VIN and test date. Vehicles were then further classified based 

on their first and last test result during the period. To avoid potential double counting of 

emissions reductions, the emissions analysis only considered the first and last result for each 

vehicle during the year and interim results were ignored. 

In the list below, the first and last results are indicated in parenthesis, where P is pass, F is fail, 

W is waiver and null indicates that there was only a single test result for a particular vehicle. 

The expected combinations that apply to the vast majority of vehicles are underlined. 

 P – Passed initial test (P/null, P/P, P/F, P/W) 

 R – Failed and successfully repaired (F/P) 

 U – Failed unresolved (F/null, F/F) 

 W – Failed and wavered (F/W) 

The difference between the initial and final tests is used to determine the percentage of tailpipe 

emissions reduction of each group. For vehicles with only one test, the final result is the same as 

the initial result. 

Adjustment of Fast-Pass Results 

A majority of vehicles tested on IM240 fast pass the test in less than the 240-second driving 

cycle. To allow for comparison of emissions of vehicles tested over different durations of the 

IM240 test cycle, the emission results for vehicles that fast-pass the IM240 inspection must be 

extrapolated. A method for projecting full test emissions was developed and implemented in the 

I/M program in 19952

 and the projected full test emissions values are stored in the test records 

and reported as the emissions results. 

Unresolved Vehicles 

When vehicles fail their initial inspection, they must obtain a repair and return for re-inspection. 

This process is normally completed in 30 days, but can take longer. Vehicles that had initial 

tests in late 2009 but completed repair and final test after February of the following year are 

treated as unresolved. Thus, the “Fail unresolved” category may be somewhat over-stated. 
31 

A number of vehicles never complete the repair/re-inspection process. In most cases, these 

vehicles are either scrapped or removed from the non-attainment area, which does reduce 

emissions in the area. Surveys in Arizona3

 and Colorado4 found that some vehicles continued to 

operate in the area in violation of the program rules, either with expired license plates or with 

stolen license plates or license plate stickers. In this report, it is assumed that two-thirds of these 

unresolved vehicles leave the area and one third continues to operate. Studies in progress in 

Colorado preliminarily indicate the percentage leaving the area is closer to 80%. 

To minimize the number of unresolved Clean Screen audit vehicles, retests of audit vehicles 

were included through the end of February 2010 and the audit vehicles were all assumed to 

remain in the area. 

First and Final Emissions Results 

Table IV-5 contains an example of the initial and final tailpipe results for 1982 to 1985 passenger 

vehicles inspected using the IM240 test. The table shows the average initial and average final 

emissions for each group of vehicles together with the percentage reduction. 

For example, of the 1,618 1985 model year passenger vehicles tested using the IM240 transient 

test, 16.6% of vehicles initially failed inspection and were repaired (Pass) with HC, CO and NOx 

reductions of 56.0%, 71.6% and 12.6% respectively. Another 8.3% of vehicles failed their initial 

inspection and had not successfully passed a retest by end February 2010 (Unresolved). 

Reductions from these vehicles are estimated to be approximately 67% for HC, CO and NOx, 

because two thirds are assumed to have left the area. Finally, 0.3% of vehicles were waived 

(Waiver) with HC, CO and NOx reductions of 0.2%, 1.2% and -70.0% respectively. In 

aggregate, including vehicles that passed their initial inspection, emission reductions for 1985 

passenger vehicles were 32.7% for HC, 38.8% for CO and 8.5% for NOx. 

Complete tables by model year and vehicle type are provided in Appendix A for vehicles tested 

using the IM240. Tables are also provided for the Clean Screen audit sample vehicles. The 

aggregate results from these tables are used to estimate the impact of the Clean Screen program. 

Audit Sample Reductions and Projected Impact 

Table IV-6 shows the aggregate first and final results for the 95% of the inspected audit sample 

vehicles that were tested using IM240. The average per vehicle emissions reductions from the 

audit sample are multiplied by the number of exempted clean screen vehicles to project the 

reductions that could have been achieved if the clean screen vehicles had instead been inspected 

at the stations. This amount is then compared to the total emission reductions from vehicles 

tested at stations to determine the impact of the Clean Screen program and the percentage of 

emissions reductions retained. 

For vehicles subject to the IM240 test, the Clean Screen program retained approximately 93-98% 

of the exhaust HC, CO and NOx reductions. These reductions assume all vehicles are driven the 

same number of miles each year. Mileage adjusted emission reductions are calculated in section 

V. 
32 

Table IV-5 Transient Test Emission Reductions for 1982-1985 Passenger Vehicles 

Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction 

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO 

1982 Pass - 331 1.70 19.88 2.01 1.70 19.88 2.01 0.0% 0.0% 

P Fail Pass 76 17.6% 4.11 46.78 2.52 1.67 17.90 2.08 59.4% 61.7% 

Fail Unresolv. 25 5.8% 8.41 68.27 2.01 2.51 21.78 0.65 70.1% 68.1% Fail Waiver 1 0.2% 14.28 142.04 0.59 14.28 142.04 0.59 0.0% 0.0% 

Total Fail% 433 23.6% 2.54 27.68 2.10 1.77 19.92 1.94 30.3% 28.0% 

1983 Pass - 655 1.40 16.53 1.96 1.40 16.53 1.96 0.0% 0.0% 

P Fail Pass 170 18.9% 3.33 48.56 2.11 1.44 15.10 2.15 56.8% 68.9% 

Fail Unresolv. 69 7.7% 5.52 80.48 1.91 1.59 24.10 0.62 71.2% 70.1% Fail Waiver 4 0.4% 2.62 80.42 1.74 2.57 75.79 1.03 2.1% 5.8% 

Total Fail% 898 27.1% 2.09 27.79 1.98 1.43 17.10 1.89 31.6% 38.5% 

1984 Pass - 985 1.33 14.69 1.98 1.33 14.69 1.98 0.0% 0.0% 

P Fail Pass 238 17.9% 3.36 43.74 2.09 1.44 13.19 2.07 57.2% 69.9% 

Fail Unresolv. 107 8.0% 5.20 67.97 2.10 1.67 22.53 0.69 67.8% 66.9% Fail Waiver 3 0.2% 3.16 49.06 1.71 3.91 65.91 1.84 -23.8% -34.3% 

Total Fail% 1,333 26.1% 2.01 24.23 2.01 1.38 15.17 1.89 31.1% 37.4% 

1985 Pass - 1,618 1.04 11.45 1.93 1.04 11.45 1.93 0.0% 0.0% 

P Fail Pass 359 16.6% 2.53 35.25 2.26 1.11 10.00 1.97 56.0% 71.6% 

Fail Unresolv. 179 8.3% 4.97 59.49 2.28 1.44 18.86 0.75 71.0% 68.3% Fail Waiver 6 0.3% 2.56 53.21 1.11 2.56 52.61 1.88 -0.2% 1.1% 

Total Fail% 2,162 25.2% 1.61 19.50 2.01 1.09 11.94 1.84 32.7% 38.8% 
33 

Table IV-6 Clean Screen Emissions Impact for Tailpipe Emissions 

C. Gas Cap Evaporative Emissions 

The evaporative emissions test used in the I/M Program is a gas cap pressure test. Leaking 

gas caps allow evaporated gasoline (HC) to escape from vehicle gas tanks into the 

atmosphere. The impact of leaking gas caps on the Clean Screen program is only evaluated in 

this report in terms of the failure rate, not in terms of repairable gas cap emissions reductions3

. 

Figure IV-7 compares the average gas cap failure rate of the Clean Screen audit sample 

vehicles to the average failure rate of the non-audit vehicles tested at stations. The failure rate 

of vehicles exempted via Clean Screen methods was 18% lower than the failure rate of 

vehicles that received a station-based test (See Figure IV-7). This result is expected because 

remote sensing is directed towards measuring tailpipe emissions. A gas cap evaporative leak 

would have to be quite large to be detected by RSD units. Clean screen models were newer 

than the overall tested fleet. 

 

3

 Although the gas cap leak rates are measured in the I/M Program, it is not clear that leak rates are directly related to the 

amount of evaporative HC emissions released from the gas tank. A small pressure leak may have the same effect as a 

large pressure leak, as long as it is sufficient to release internal gas tank pressure over a period of an hour or so. 

IM240 Tailpipe Emissions

Vehicles HC g/mi CO g/mi NOx g/mi

Audit Sample 3,887

Mean Initial 0.182 2.396 0.569

Mean Final 0.176 2.316 0.551

Emissions reduction 0.007 0.079 0.018

Clean Screens 199,344

Potential Reductions 1,297 15,825 3,595 

Station Vehicles 636,923

Mean Initial 0.444 5.227 0.872

Mean Final 0.333 3.946 0.790

Emissions reduction 0.111 1.281 0.082

In station reductions 70,760 815,703 52,175 

Combined CS & Stn 836,267 72,058 831,528 55,770 

Clean Screen Impact 1.8% 1.9% 6.4%

Retained Reductions 98.2% 98.1% 93.6%
34 

Figure IV-7 Gas Cap Pressure Failure Rates 

Using the fail rates identified in the audit sample, Table IV-7 shows the projected gas cap 

failures that would have been found in the exempted clean screen vehicles. These projected 

gas cap failures are added to the actual gas cap failures identified in initial inspections at the 

test stations to provide the total possible gas cap failure rate for the program. Vehicles with a 

redeemed Clean Screen notice account for 18.5% of the total possible gas cap failures. 

Therefore, 81.5% of evaporative gas cap HC emission reductions were retained. 

In general, it is desirable to use direct measurements of emissions to evaluate program 

performance rather than a model. Unlike exhaust emissions that are directly measured using 

tailpipe tests, however, emissions rates from gas caps cannot easily be directly measured. 

Emissions rates of vapor leaks are typically determined in a test laboratory by enclosing a 

vehicle in a sealed compartment and measuring the emissions released into the compartment 

over time, which is impractical for testing many vehicles. Therefore, the EPA mobile source 

emissions model, Mobile6.2, was used to estimate the fraction of emissions benefits derived 

from gas cap inspections. 

CDPHE provided results from Mobile6.2 models of the benefits of the I/M program for 2009. 

The projected average reduction in HC emissions of the area fleet was 0.095 g/mi. This was 

comprised of 0.074 g/mi resulting from exhaust emissions inspections and 0.021 g/mi from 

the Gas Cap testing. The measured I/M exhaust reductions (see section V) were 691.8 tons. 

Assuming the 0.074 g/mi corresponded to 691.8 tons, the Gas Cap related HC reductions were 

projected to be 196.3 tons. These results are shown in Table IV-8. The RapidScreen impact 

was projected as 35.9 tons or 4.0% of the I/M program reductions. 

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

Pressure Failure Missing Cap

Nature of Failure

2009 Gas Cap Pressure Failure Rates

Clean Screen Station
35 

Table IV-7 Clean Screen Impact on Evaporative HC Emissions 

Table IV-8 Gas Cap Related Benefit Tons 

 

Initial Tests

Pressure 

Failure

Missing 

Cap

Total 

Fails

RapidScreen Audit 4,103 122 2 124 

3.0% 0.0% 3.0%

Projected RapidScreen 199,344 5,927 97 6,025 

Station GC Tests 715,137 26,031 897 26,928 

3.6% 0.1% 3.8%

Total Program 914,481 31,958 994 32,953 

RapidScreen Impact 21.8% 18.5% 9.8% 18.3%

Retained Reductions 78.2% 81.5% 90.2% 81.7%

Mobile6 Estimates (from CDPHE)

2009 M6 

g/mi HC

I/M 

2009 

HC tons

I/M Exhaust emission reductions 0.074 691.8

Projected Gas Cap Evap Emissions reductions 0.021 196.3

I/M Program total HC reductions 0.095 888.1

Gas Cap Evap RapidScreen impact 18% 0.004 35.9

% of I/M program HC benefit 4.0%
36 

D. Hybrid RSD-LEI vs. 2-hit RSD 

ESP compared the effectiveness of the ‘Hybrid’ and ‘2-RSD’ screening methods. The Hybrid 

method uses a single RSD measurement and a low emitter index (LEI) table. The 2-RSD 

method uses two RSD measurements. 

The audit sample of vehicles with IM240 tests contained 2,774 vehicles screened using the 2-

RSD method and 1,113 vehicles screened using Hybrid RSD-LEI method. Table IV-9 shows 

the emissions reductions for these two samples and the average for all vehicles inspected at 

stations. Figures IV-2 and IV-3 show the average initial emissions and emissions reductions 

for each sample. 

The 2-RSD method audit vehicles had initial emissions that were 52%, 55% and 77% of the 

overall I/M fleet average for HC and CO and NOx respectively. The relatively higher average 

for NOx in part reflects the absence of an RSD NO cutpoint. The Hybrid RSD-LEI method 

audit vehicles had lower initial emissions that were 38%, 45% and 62% of the I/M fleet 

average for HC and CO and NOx respectively. 

Average emissions reductions for the 2-RSD audit vehicles were 2.0%, 1.8% and 2.7% of 

fleet average initial emissions for HC and CO and NOx respectively. Average emissions 

reductions for the Hybrid RSD-LEI audit vehicles were 0.9%, 1.6% and 1.1% of fleet average 

initial emissions for HC and CO and NOx respectively. These compared to station average 

reductions of 29.1%, 28.1% and 10.2% for HC, CO and NOx respectively. The Hybrid RSDLEI audit vehicles had lower initial emissions and lower reductions than the 2-RSD audit 

vehicles. 
37 

Table IV-9 Average Emissions per Vehicle 

Figure IV-2 Average Initial IM240 Emissions 

Vehicle IM240 Tailpipe Emissions

Sample Vehicles HC g/mi CO g/mi NOx g/mi

I/M vehicle initial mean emissions 0.382 4.552 0.800

2-RSD Audits 2,774

Mean Initial 0.197 2.535 0.599

Mean Final 0.189 2.453 0.578

Emissions reduction 0.008 0.083 0.022

 % of I/M vehicle initial mean emissions 2.0% 1.8% 2.7%

Hybrid Audits 1,113

Mean Initial 0.146 2.047 0.492

Mean Final 0.142 1.976 0.484

Emissions reduction 0.004 0.071 0.009

 % of I/M vehicle initial mean emissions 0.9% 1.6% 1.1%

All Station Tests 636,923

Mean Initial 0.444 5.227 0.872

Mean Final 0.333 3.946 0.790

Emissions reduction 0.111 1.281 0.082

 % of I/M vehicle initial mean emissions 29.1% 28.1% 10.2%

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Station

RSD-2

RSDLEI

g/mi

HC

0.0

1.0

2.0

3.0

4.0

5.0

6.0

Station

RSD-2

RSDLEI

CO

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Station

RSD-2

RSDLEI

NOx
38 

Figure IV-3 Average IM240 Emissions Reductions 

 

0.00

0.02

0.04

0.06

0.08

0.10

0.12

Station

RSD-2

RSDLEI

g/mi

HC

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Station

RSD-2

RSDLEI

CO

0.00

0.02

0.04

0.06

0.08

0.10

Station

RSD-2

RSDLEI

NOx
39 

V. Estimate of Overall I/M Program Benefits and Clean Screen 

Impact 

Overall I/M program emission reductions derive from two main components: 

○ Reductions resulting directly from I/M inspections and consequent repairs; 

○ Reductions from repair activities that are performed in anticipation of an I/M 

inspection. 

In previous years, it was assumed the vast majority of emissions reductions were directly 

measurable by comparing the initial and final I/M inspection emissions results, i.e. the first 

component described above. This report uses the same methodology. However, it is 

acknowledged that by 2007 most vehicles were equipped with OBD-II malfunction indicator 

lights. It is believed that some repairs of these newer model vehicles are performed in 

response to warning lights before the initial inspection. The benefits of these repairs are not 

directly measurable in the program testing. 

The Clean Screen disbenefit can be projected directly from the emissions testing of the audit 

sample. There may be unmeasured offsetting benefits if the Clean Screen program 

encourages owners to maintain malfunctioning vehicles sooner than otherwise. 

For this report, measured I/M exhaust emissions benefits were projected from the IM240 and 

Idle emissions tests. In the case of Idle tests, idle test emission concentrations were converted 

to equivalent IM240 g/mi emissions. 

For each model year, the IM240 g/mi emissions values were weighted by the annual vehicle 

miles traveled to project the emissions inventory for initial and final test and, hence, the direct 

program benefits. 

The following sections project the directly measured tons of emissions and reductions 

A. Conversion of Idle Tests to IM240 Equivalent emissions 

On-road remote sensing emissions of vehicles inspected at I/M stations have been used to 

project IM240 equivalent values for Idle test emissions. 

The idle test procedure includes a low-speed idle and a high speed idle at 2500rpm. 1980 and 

older vehicle models are required to pass the low-speed idle. 1981 and newer models must 

pass both the low-speed and the high-speed tests. 

Figures V-1 and V-2 show the correlation between idle tests and on-road HC and CO 

emissions of the same vehicles. Results are averaged by model year. Average initial and 

final test emissions were used for vehicles that initially failed and were retested. Model years 

were grouped together for 1965-and-older, 1966 to 1970, 1971 to 1975, 1976 to 1981, 1982 to 

1985, 1986 to 1990 and 2004-and-newer. Even with these groups, there were less than 100 

matching RSD measurements for Passenger vehicles in groups from 1982 to 1998. There 

were several hundred matching RSD measurements for each truck group. Trend lines were 

plotted with an intercept of zero to obtain RSD / Idle Test emissions ratios. 
40 

Similarly, Figure V-3 shows the correlation between IM240 and on-road emissions. Trend 

lines were plotted with an intercept of zero for HC and CO emissions to obtain IM240 / RSD 

emissions ratios. The results are summarized in Tables V-1 and V-2. 

Figure V-1 RSD vs. Idle Test Emissions 

Table V-1 Low Speed Idle to IM240 

Truck Idle Test and Matching Vehicle 

RSD Emissions

 (RSD N=57,867)

y = 1.0336x

R2

 = 0.9242

0

100

200

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800

Idle HC ppm

RSD HC ppm

Passenger Idle Test and Matching

Vehicle RSD Emissions

 (RSD N=8,843)

y = 1.1007x

R2

 = 0.8169

0

100

200

300

400

500

600

- 100 200 300 400 500 600

Idle HC ppm

RSD HC ppm

Passenger Idle Test and Matching

Vehicle RSD Emissions

 (RSD N=8,843)

y = 1.3267x

R2

 = 0.712

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0.0 1.0 2.0 3.0 4.0

Idle CO %

RSD CO %

Truck Idle Test Test and Matching

Vehicle RSD Emissions

 (RSD N=57,867)

y = 1.5121x

R2

 = 0.7963

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Idle CO %

RSD CO %

Low Speed Idle test to IM240 Projection

Passenger HC HC R2 CO CO R2

RSD / Idle 1.1007 0.81 1.3267 0.71

IM240 / RSD 0.0087 0.98 15.947 0.92

IM240 / Idle 0.0096 21.1569

Truck HC HC R2 CO CO R2

RSD / Idle 1.0336 0.92 1.5121 0.8

IM240 / RSD 0.0111 0.98 18.765 0.94

IM240 / Idle 0.0115 28.3746
41 

Figure V-2 RSD vs. 2500 Idle Test Emissions 

Table V-2 Low Speed Idle to IM240 

Using the ratios derived above, IM240 g/mi equivalent emissions were projected for the 

vehicles tested with the idle test procedure. The low speed idle results were used to estimate 

emissions reductions as all model year vehicles tested at idle were required to pass the low 

speed idle test. 

Model Year Average Truck Idle 2500 Test and 

Matching Vehicle RSD Emissions

 (RSD N=57,867)

y = 1.548x

R2

 = 0.927

0

100

200

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800

Idle HC ppm

RSD HC ppm

Model Year Average Passenger Idle 2500 Test 

and Matching Vehicle RSD Emissions (RSD 

N=8,843)

y = 1.5353x

R2

 = 0.8565

0

100

200

300

400

500

600

0 100 200 300 400 500 600

Idle HC ppm

RSD HC ppm

Model Year Average Passenger Idle 2500 Test 

and Matching Vehicle RSD Emissions (RSD 

N=8,843)

y = 1.1789x

R2

 = 0.8169

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0.0 1.0 2.0 3.0 4.0

Idle CO %

RSD CO %

Model Year Average Truck Idle 2500 Test and 

Matching Vehicle RSD Emissions

 (RSD N=57,867)

y = 1.4699x

R2

 = 0.8185

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Idle CO %

RSD CO %

2500 RPM Idle test to IM240 Projection

Passenger HC HC R2 CO CO R2

RSD / 2500 1.5353 0.86 1.1789 0.82

IM240 / RSD 0.0087 0.98 15.947 0.92

IM240 / 2500 0.0134 18.7999

Truck HC HC R2 CO CO R2

RSD / 2500 1.548 0.93 1.4699 0.82

IM240 / RSD 0.0111 0.98 18.765 0.94

IM240 / 2500 0.0172 27.5827
42 

Figure V-3 RSD vs. 2500 Idle Test Emissions 

Model Year Average Passenger IM240 Test and 

Matching Vehicle RSD Emissions

 (RSD N=449,842)

y = 0.0087x

R2

 = 0.9812

0.0

0.5

1.0

1.5

2.0

2.5

0 50 100 150 200 250

RSD HC ppm

IM240 HC g/mi

Model Year Average Passenger IM240 Test and 

Matching Vehicle RSD Emissions

 (RSD N=449,842)

y = 15.947x

R2

 = 0.9229

0

5

10

15

20

25

30

0.0 0.3 0.5 0.8 1.0 1.3 1.5

RSD CO %

IM240 CO g/mi

Model Year Average Passenger IM240 Test and 

Matching Vehicle RSD Emissions

 (RSD N=449,842)

y = 0.0016x + 0.1754

R2

 = 0.9885

0.0

0.5

1.0

1.5

2.0

2.5

0 250 500 750 1000 1250 1500

RSD NO ppm

IM240 NOx g/mi

Model Year Average Truck IM240 Test and 

Matching Vehicle RSD Emissions

 (RSD N=423,746)

y = 0.0111x

R2

 = 0.9756

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0 50 100 150 200 250 300 350 400

RSD HC ppm

IM240 HC g/mi

Model Year Average Truck IM240 Test and 

Matching Vehicle RSD Emissions

 (RSD N=423,746)

y = 18.765x

R2

 = 0.9368

0

10

20

30

40

50

60

0.0 0.5 1.0 1.5 2.0 2.5 3.0

RSD CO %

IM240 CO g/mi

Model Year Average Truck IM240 Test and 

Matching Vehicle RSD Emissions

 (RSD N=423,746)

y = 0.0016x + 0.3013

R2

 = 0.9785

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 500 1000 1500 2000

RSD NO ppm

IM240 NOx g/mi
43 

B. Annual Mileage Weighting 

Because of data entry errors and odometer rollover on older, high mileage vehicles, obtaining 

estimates of annual mileage from the I/M Program odometer readings for each model year 

and type of vehicle is not recommended. To avoid these problems, annual mileages for 

vehicles were taken from the 2008 ERG report on Colorado mileage accumulation rates5

. 

The estimated annual mileages are shown in Table V-3 for LDGVs and LDGTs. In Table VI3 the mileage accumulation rates for LDGT2, 3 and 4 were weighted together to obtain a 

single LDGT value. This table indicates that newer model year vehicles are driven more miles 

annually than older vehicles. It also indicates that 1995 and newer model year LDGTs, which 

emit greater masses of pollution than LDGVs are driven more miles annually than 1995 and 

newer model year LDGVs. 

Table V-3 Estimated Annual Mileage in 2009 

Year LDGV LDGT

1980 4304 4,554 

1981 4304 4,562 

1982 4434 4,583 

1983 4481 4,630 

1984 4502 4,668 

1985 4552 4,741 

1986 4,780 4,851 

1987 5,088 5,019 

1988 5,430 5,256 

1989 5,672 5,519 

1990 6,002 5,824 

1991 6,331 6,135 

1992 6,653 6,471 

1993 6,974 6,940 

1994 7,369 7,437 

1995 7,764 7,863 

1996 8,188 8,345 

1997 8,613 8,900 

1998 9,032 9,502 

1999 9,450 10,087 

2000 9,905 10,727 

2001 10,360 11,245 

2002 10,746 11,817 

2003 11,132 12,303 

2004 11,870 12,834 

2005 12,023 13,215 

2006 12,307 13,433 

2007 12,357 13,514 

2008 11,600 12,428 

2009 9,650 8,995 
44 

C. Annual Emissions Reductions 

Annual tons of emissions were projected for vehicle type and model year by multiplying the 

numbers of vehicles by annual mileage and average g/mi emission levels. Results were 

projected for initial tests and final tests to determine the initial and final tons of emissions and, 

therefore, the tons of reduction. The results are listed in Appendix B for IM240 and Idle tests. 

Table V-4 first shows the reductions from the Clean Screen audit tests. Based on the audit 

tests, the second part of the table projects the potential reductions from the Clean Screen 

vehicles if all vehicles with redeemed Clean Screen notices had been tested at a station. The 

third part of the table shows the reductions from the vehicles that were tested at inspection 

stations, which includes the Clean Screen audit vehicles. The total potential reductions from 

the program are the combination of the potential reductions from the Clean Screened vehicles 

plus the actual reductions from the vehicles tested at stations. 

In Table IV-4, Clean Screen effectiveness was expressed without reference to the annual 

vehicle miles traveled (VMT) by each model year of vehicles. The more complete analysis in 

Table V-4 shows the Clean Screen program effectiveness when the VMT and Gas Cap4

estimates are factored in. During 2009, the Clean Screen program retained 94.6%, 98.1% and 

92.9% respectively of potential HC, CO and NOx emission reductions in vehicles subject to 

testing. 

For vehicles initially tested in calendar year 2009, the I/M Program is projected to have 

eliminated 840.1 tons of HC, 7,485.7 tons of CO and 463.7 tons of NOx for one year of 

vehicle travel – based on the IM240 driving cycle. 

Because the program is biennial, these reductions are approximately half of the reductions 

that would be measured over a full two-year cycle of the program. 

The tons of reductions cited here do not relate directly to the total mobile emissions inventory. 

The reductions cited are for tailpipe emissions and are in terms of the IM240 driving cycle. 

State Implementation Plan reductions are based on different driving cycles, are subject to 

many adjustments for speed, road type, temperature, air conditioning loads, etc., and therefore 

are larger than the IM240 measured reductions. 

As noted earlier, the reductions shown do not include reductions from maintenance actions 

performed on vehicles before their initial inspection. These may be quite substantial, 

especially for OBD-II vehicles that turn on the check engine light to alert owners to problems. 

 

4

 The evaporative emissions have not been adjusted for mileage but the effect of an adjustment would be small. Gas cap 

failures are more evenly distributed by age than tailpipe failures and only part of the evaporative emissions are running 

losses dependent on miles traveled. 
45 

Table V-4 Estimated Annual Tons Of Reduction (IM240 and Idle Tested Vehicles 

* NOx is not reported for idle tests. 

Table V-4 also shows that, during for the calendar year 2009, 199,344 unique vehicles were 

exempted through Clean Screen, and 700,302 vehicles received a station test. Therefore, 22% 

of the 899,646 unique vehicles were Clean Screened. 

If the fraction of Clean Screen vehicles had been 30% of vehicles subject to inspection there 

would have be 269,894 Clean Screens and 629,752 Station tests. Assuming this increase was 

achieved by increasing on-road fleet coverage rather than by relaxing the Clean Screen 

standards, the projected emissions retained would have been 92.7%, 97.1% and 89.6% 

respectively of potential HC, CO and NOx tailpipe emission reductions. 

 Audit Vehicle Reductions (tons/yr)

Audit Tests

Unique 

Vehicles HC CO NOx

Enhanced IM240 3,887 0.24 2.87 0.69

Potential from RS Vehicles (tons/yr)

RapidScreen

Unique 

Vehicles HC CO NOx

Enhanced Area 199,344 12.2 147.4 35.4

Gas Cap estimate from Mobile6 35.9

Station Reductions (tons/yr)

Station I/M Vehicles

Unique 

Vehicles HC CO NOx

Enhanced IM240 636,923 542.9 6,212.5 463.7

Enhanced Idle* 63,379 136.7 1,273.2

Gas Cap estimate from Mobile6 160.4

 840.1 700,302 7,485.7 463.7 

Total Potential Reductions 888.1 7,633.1 499.2

RapidScreen Exhaust Impact 1.4% 1.9% 7.1%

Rapidscreen Gas Cap Impact 4.0%

Retained Reductions 94.6% 98.1% 92.9%
46 

VI. Proposed Adjustments to Clean Screen Standards 

The 2008 report1 contained an extensive ‘what if’ analysis to determine how clean screen 

standards should be adjusted to match the May 5, 2008 changes in I/M standards. 

Conclusions from that analysis were: 

1. As a result of the tightening of the I/M standards in 2008, it would be appropriate to 

also adjust the clean screening standards. 

2. The 2-RSD method was relatively insensitive to tightening RSD standards for HC and 

CO. Tighter cutpoints would reduce NOx losses. 

3. The application of the LEI2008 table with a 2% fail rate cutpoint was projected to 

substantially reduce the lost emissions reductions from the RSD-LEI sample but to 

also reduce the number of RSD-LEI clean screens by 30%. 

4. The addition of an RSD NO cutpoint of 1500ppm in combination with a 7.5% 

LEI2008 fail rate cutpoint was projected to produce similar results to the 2% LEI 

cutpoint noted above while retaining 87% of the 2008 clean screens. 

5. The same combination of RSD NO cutpoint of 1500ppm in combination with a 7.5% 

LEI2008 fail rate cutpoint applied to the 2-RSD clean screen sample was projected to 

achieve similar results to those from the RSD-LEI sample while retaining 86% of the 

2008 clean screens. 

6. If the combination of an added RSD NO cutpoint of 1500ppm and a 7.5% LEI2008 

fail rate cutpoint had been applied to both 2-RSD and RSD-LEI clean screen vehicles 

in 2008 then 98%, 96% and 97% of HC, CO and NOx exhaust reductions would have 

been retained. This combination of cutpoints was recommended for implementation. 

In 2009, the LEI table was tightened and, as shown earlier in the report, the lost emissions 

reductions from the Hybrid RSD-LEI method were substantially reduced as anticipated in 3) 

above. 

The implementation of the NOx cutpoint is still pending and is anticipated in 2010. 

The application of a loose LEI standard to 2-RSD results is under review. 
47 

VII. IM240 Projected Emissions by Model Year 

Figures VII-1 through VII-6 show the annual emissions inventories and reductions by model 

year and vehicle type for the vehicles tested in 2009 at stations, based on the IM240 driving 

cycle. The projected exhaust emissions inventory for the Clean Screen vehicles and Idle 

tested vehicles are also shown. The biennial testing cycle of the Enhanced area causes the 

difference between the sizes of the bars for odd model year vehicles vs. even model year 

vehicles. 

Not included in these charts: 

 most 2006 and newer models that had not yet entered the testing program; 

 any estimate of pre-inspection emission reductions; 

 NOx emissions for 63,000 vehicles tested with the idle test: 1981 and older models 

17,400 (27%), 1982 and newer trucks 42,600 (67%), and 1982 & newer passenger 

vehicles 3,300 (5%). 

The Figures VII-1 to 6 illustrate that older vehicles, which are fewer in number and driven 

fewer miles each year, still contribute many tons of excess emissions in the Denver 

metropolitan area. 
48 

Figure VII-1 LDGV HC Reductions and Remaining Emissions 

Figure VII-2 LDGT HC Reductions and Remaining Emissions 

0

50

100

150

200

250

300

P 1965&older

P 1966-70P 1971-75P 1976-81

P 1982P 1983P 1984P 1985P 1986P 1987P 1988P 1989P 1990P 1991P 1992P 1993P 1994P 1995P 1996P 1997P 1998P 1999P 2000P 2001P 2002P 2003P 2004P 2005P 2006P 2007P 2008P 2009P 2010

IM240 Equivalent Exhaust Tons Per Year in 2009

Passenger HC

Idle Reduction HC

IM240 Reduction HC

Idle Final HC

IM240 Final HC

Clean Screen Vehicles HC 

0

50

100

150

200

250

300

T 1965&older

T 1966-70T 1971-75T 1976-81

T 1982T 1983T 1984T 1985T 1986T 1987T 1988T 1989T 1990T 1991T 1992T 1993T 1994T 1995T 1996T 1997T 1998T 1999T 2000T 2001T 2002T 2003T 2004T 2005T 2006T 2007T 2008T 2009T 2010

IM240 Equivalent Exhaust Tons Per Year in 2009

Light Truck HC

Idle Reduction HC

IM240 Reduction HC

Idle Final HC

IM240 Final HC

Clean Screen Vehicles HC 
49 

Figure VII-3 LDGV CO Reductions and Remaining Emissions 

Figure VII-4 LDGT CO Reductions and Remaining Emissions 

0

500

1,000

1,500

2,000

2,500

P 1965&older

P 1966-70P 1971-75P 1976-81

P 1982P 1983P 1984P 1985P 1986P 1987P 1988P 1989P 1990P 1991P 1992P 1993P 1994P 1995P 1996P 1997P 1998P 1999P 2000P 2001P 2002P 2003P 2004P 2005P 2006P 2007P 2008P 2009P 2010

IM240 Equivalent Exhaust Tons Per Year in 2009

Passenger CO

Idle Reduction CO

IM240 Reduction CO

Idle Final CO

IM240 Final CO

Clean Screen Vehicles CO

0

500

1,000

1,500

2,000

2,500

T 1965&older

T 1966-70T 1971-75T 1976-81

T 1982T 1983T 1984T 1985T 1986T 1987T 1988T 1989T 1990T 1991T 1992T 1993T 1994T 1995T 1996T 1997T 1998T 1999T 2000T 2001T 2002T 2003T 2004T 2005T 2006T 2007T 2008T 2009T 2010

IM240 Equivalent Exhaust Tons Per Year in 2009

Light Truck CO

Idle Reduction CO

IM240 Reduction CO

Idle Final CO

IM240 Final CO

Clean Screen Vehicles CO
50 

Figure VII-5 LDGV NOx Reductions and Remaining Emissions 

Figure VII-6 LDGT NOx Reductions and Remaining Emissions 

0

50

100

150

200

250

300

350

400

450

500

P 1965&older

P 1966-70P 1971-75P 1976-81

P 1982P 1983P 1984P 1985P 1986P 1987P 1988P 1989P 1990P 1991P 1992P 1993P 1994P 1995P 1996P 1997P 1998P 1999P 2000P 2001P 2002P 2003P 2004P 2005P 2006P 2007P 2008P 2009P 2010

IM240 Equivalent Exhaust Tons Per Year in 2009

Passenger NOx

Idle Reduction NOx n/a

IM240 Reduction NOx

Idle Final NOx n/a

IM240 Final NOx

Clean Screen Vehicles NOx

0

50

100

150

200

250

300

350

400

450

500

T 1965&older

T 1966-70T 1971-75T 1976-81

T 1982T 1983T 1984T 1985T 1986T 1987T 1988T 1989T 1990T 1991T 1992T 1993T 1994T 1995T 1996T 1997T 1998T 1999T 2000T 2001T 2002T 2003T 2004T 2005T 2006T 2007T 2008T 2009T 2010

IM240 Equivalent Exhaust Tons Per Year in 2009

Light Truck NOx

Idle Reduction NOx n/a

IM240 Reduction NOx

Idle Final NOx n/a

IM240 Final NOx

Clean Screen Vehicles NOx
51 

References 

 

1

 “The Colorado Remote Sensing Program January – December 2008”, ESP report for the Colorado 

Department of Public Health and Environment, July 2010

2

 Klausmeier R., “Technical Note: Estimating Full IM240 Emissions Based on Fast Pass Emission 

Results”, November 2005 

3

 Wenzel, T. “Evaluation of Arizona’s Enhanced I/M Program”, Presented at the 9th CRC On-Road 

Vehicle Emissions Workshop. April 1999. 

4

 McClintock, P. “The Denver Remote Sensing Clean Screening Pilot”, ESP report for the Colorado 

Department of Health and Environment, December 1999. 

5

 “Colorado Mileage Accumulation Rates from VID Odometer Readings Draft Report” for CDPHE by 

Eastern Research Group, Inc. June 30, 2008
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1982 Pass - 331 1.70 19.88 2.01 1.70 19.88 2.01 0.0% 0.0% 0.0%

P Fail Pass 76 17.6% 4.11 46.78 2.52 1.67 17.90 2.08 59.4% 61.7% 17.1%

Fail Unresolv. 25 5.8% 8.41 68.27 2.01 2.51 21.78 0.65 70.1% 68.1% 67.9%

Fail Waiver 1 0.2% 14.28 142.04 0.59 14.28 142.04 0.59 0.0% 0.0% 0.0%

Total Fail% 433 23.6% 2.54 27.68 2.10 1.77 19.92 1.94 30.3% 28.0% 7.4%

1983 Pass - 655 1.40 16.53 1.96 1.40 16.53 1.96 0.0% 0.0% 0.0%

P Fail Pass 170 18.9% 3.33 48.56 2.11 1.44 15.10 2.15 56.8% 68.9% -2.1%

Fail Unresolv. 69 7.7% 5.52 80.48 1.91 1.59 24.10 0.62 71.2% 70.1% 67.4%

Fail Waiver 4 0.4% 2.62 80.42 1.74 2.57 75.79 1.03 2.1% 5.8% 40.9%

Total Fail% 898 27.1% 2.09 27.79 1.98 1.43 17.10 1.89 31.6% 38.5% 4.7%

1984 Pass - 985 1.33 14.69 1.98 1.33 14.69 1.98 0.0% 0.0% 0.0%

P Fail Pass 238 17.9% 3.36 43.74 2.09 1.44 13.19 2.07 57.2% 69.9% 1.0%

Fail Unresolv. 107 8.0% 5.20 67.97 2.10 1.67 22.53 0.69 67.8% 66.9% 67.1%

Fail Waiver 3 0.2% 3.16 49.06 1.71 3.91 65.91 1.84 -23.8% -34.3% -7.5%

Total Fail% 1,333 26.1% 2.01 24.23 2.01 1.38 15.17 1.89 31.1% 37.4% 5.8%

1985 Pass - 1,618 1.04 11.45 1.93 1.04 11.45 1.93 0.0% 0.0% 0.0%

P Fail Pass 359 16.6% 2.53 35.25 2.26 1.11 10.00 1.97 56.0% 71.6% 12.6%

Fail Unresolv. 179 8.3% 4.97 59.49 2.28 1.44 18.86 0.75 71.0% 68.3% 66.9%

Fail Waiver 6 0.3% 2.56 53.21 1.11 2.56 52.61 1.88 -0.2% 1.1% -70.0%

Total Fail% 2,162 25.2% 1.61 19.50 2.01 1.09 11.94 1.84 32.7% 38.8% 8.5%

1986 Pass - 1,847 0.96 10.04 1.95 0.96 10.04 1.95 0.0% 0.0% 0.0%

P Fail Pass 315 13.6% 2.62 34.48 2.05 1.05 8.82 1.89 59.8% 74.4% 7.8%

Fail Unresolv. 158 6.8% 4.51 52.03 2.33 1.33 16.50 0.75 70.6% 68.3% 67.8%

Fail Waiver 3 0.1% 1.21 23.21 2.85 1.66 24.66 2.36 -37.0% -6.3% 17.5%

Total Fail% 2,323 20.5% 1.43 16.22 1.99 1.00 10.33 1.86 30.1% 36.3% 6.5%

1987 Pass - 2,898 0.89 9.29 1.76 0.89 9.29 1.76 0.0% 0.0% 0.0%

P Fail Pass 482 13.4% 2.53 29.69 2.28 1.04 8.49 1.91 59.0% 71.4% 16.3%

Fail Unresolv. 217 6.0% 4.07 50.91 2.33 1.30 15.91 0.80 68.1% 68.7% 65.9%

Fail Waiver 4 0.1% 2.32 39.85 1.59 2.57 53.15 1.54 -11.0% -33.4% 3.5%

Total Fail% 3,601 19.5% 1.30 14.56 1.86 0.94 9.63 1.72 28.1% 33.9% 7.6%

1988 Pass - 3,048 0.82 9.06 1.69 0.82 9.06 1.69 0.0% 0.0% 0.0%

P Fail Pass 504 13.3% 2.41 28.83 2.02 0.92 8.40 1.73 61.7% 70.9% 14.4%

Fail Unresolv. 226 6.0% 4.11 44.32 2.28 1.27 14.96 0.75 69.0% 66.2% 67.0%

Fail Waiver 9 0.2% 2.98 39.26 1.92 2.70 37.23 1.58 9.4% 5.2% 17.6%

Total Fail% 3,787 19.5% 1.23 13.87 1.77 0.86 9.39 1.64 29.9% 32.3% 7.4%

1989 Pass - 4,905 0.72 8.54 1.54 0.72 8.54 1.54 0.0% 0.0% 0.0%

P Fail Pass 676 11.5% 2.37 29.60 2.09 0.87 8.70 1.79 63.2% 70.6% 14.0%

Fail Unresolv. 271 4.6% 4.55 45.85 2.32 1.51 15.04 0.75 66.8% 67.2% 67.8%

Fail Waiver 5 0.1% 5.15 49.47 2.55 5.23 36.82 2.40 -1.7% 25.6% 5.8%

Total Fail% 5,857 16.3% 1.09 12.73 1.64 0.78 8.88 1.53 28.7% 30.2% 6.5%

A1-1
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1990 Pass - 6,197 0.71 7.92 1.55 0.71 7.92 1.55 0.0% 0.0% 0.0%

P Fail Pass 851 11.5% 2.17 25.48 2.32 0.86 7.96 1.74 60.5% 68.8% 25.1%

Fail Unresolv. 351 4.7% 4.35 44.92 2.70 1.35 14.26 0.87 68.9% 68.3% 67.7%

Fail Waiver 7 0.1% 2.61 30.70 3.80 3.52 51.55 3.86 -34.6% -67.9% -1.4%

Total Fail% 7,406 16.3% 1.06 11.71 1.69 0.76 8.26 1.54 27.6% 29.4% 9.1%

1991 Pass - 8,864 0.58 6.88 1.39 0.58 6.88 1.39 0.0% 0.0% 0.0%

P Fail Pass 1,101 10.6% 2.01 22.15 2.20 0.70 6.96 1.58 65.1% 68.6% 28.4%

Fail Unresolv. 447 4.3% 3.63 35.04 2.70 1.16 11.30 0.87 67.9% 67.8% 67.8%

Fail Waiver 15 0.1% 3.69 44.57 2.84 3.24 36.11 2.60 12.4% 19.0% 8.3%

Total Fail% 10,427 15.0% 0.87 9.75 1.53 0.62 7.12 1.39 28.1% 27.0% 9.5%

1992 Pass - 8,411 0.55 6.32 1.37 0.55 6.32 1.37 0.0% 0.0% 0.0%

P Fail Pass 1,140 11.3% 1.97 23.72 2.08 0.66 6.26 1.57 66.6% 73.6% 24.4%

Fail Unresolv. 492 4.9% 3.23 36.19 2.48 1.10 11.82 0.81 65.9% 67.3% 67.4%

Fail Waiver 10 0.1% 2.46 37.79 2.17 2.39 33.68 1.82 3.0% 10.9% 15.9%

Total Fail% 10,053 16.3% 0.84 9.79 1.50 0.59 6.61 1.36 30.0% 32.5% 9.3%

1993 Pass - 11,359 0.51 5.72 1.31 0.51 5.72 1.31 0.0% 0.0% 0.0%

P Fail Pass 1,394 10.5% 2.02 23.30 2.14 0.65 6.26 1.57 68.0% 73.1% 26.5%

Fail Unresolv. 504 3.8% 3.53 31.75 2.78 1.11 10.05 0.92 68.5% 68.4% 66.9%

Fail Waiver 9 0.1% 3.03 14.82 3.42 4.40 21.27 2.89 -45.4% -43.6% 15.6%

Total Fail% 13,266 14.4% 0.78 8.56 1.45 0.55 5.95 1.32 30.1% 30.5% 9.0%

1994 Pass - 12,776 0.41 4.97 1.06 0.41 4.97 1.06 0.0% 0.0% 0.0%

P Fail Pass 1,340 9.2% 1.91 19.12 1.98 0.51 5.36 1.35 73.5% 72.0% 31.8%

Fail Unresolv. 482 3.3% 2.93 27.83 2.63 0.98 8.90 0.87 66.8% 68.0% 66.8%

Fail Waiver 16 0.1% 4.08 25.36 2.87 3.62 21.70 2.79 11.2% 14.5% 2.8%

Total Fail% 14,614 12.6% 0.63 7.05 1.19 0.44 5.16 1.08 30.6% 26.8% 9.7%

1995 Pass - 16,664 0.38 4.31 0.96 0.38 4.31 0.96 0.0% 0.0% 0.0%

P Fail Pass 1,660 8.8% 1.57 16.19 1.83 0.47 4.54 1.20 69.9% 72.0% 34.4%

Fail Unresolv. 600 3.2% 2.97 24.86 2.54 0.91 8.06 0.84 69.4% 67.6% 66.8%

Fail Waiver 15 0.1% 1.86 27.32 2.69 1.83 23.68 2.57 1.4% 13.3% 4.2%

Total Fail% 18,939 12.0% 0.56 6.02 1.09 0.40 4.46 0.98 28.6% 25.9% 10.0%

1996 Pass - 15,310 0.31 3.68 0.81 0.31 3.68 0.81 0.0% 0.0% 0.0%

P Fail Pass 1,305 7.7% 1.08 12.97 1.61 0.37 4.18 0.99 65.7% 67.8% 38.5%

Fail Unresolv. 397 2.3% 2.29 21.47 2.41 0.74 6.94 0.78 67.9% 67.7% 67.5%

Fail Waiver 11 0.1% 1.49 14.32 3.20 1.24 14.45 3.00 17.0% -0.9% 6.2%

Total Fail% 17,023 10.1% 0.41 4.81 0.91 0.32 3.80 0.82 22.0% 21.0% 9.4%

1997 Pass - 20,310 0.29 3.48 0.75 0.29 3.48 0.75 0.0% 0.0% 0.0%

P Fail Pass 1,425 6.5% 0.90 12.92 1.46 0.34 3.95 0.92 62.5% 69.4% 37.0%

Fail Unresolv. 324 1.5% 2.25 20.40 2.58 0.67 6.46 0.85 70.2% 68.3% 67.0%

Fail Waiver 5 0.0% 1.84 22.66 3.32 0.65 11.54 3.12 64.9% 49.1% 5.9%

Total Fail% 22,064 7.9% 0.36 4.34 0.82 0.30 3.55 0.76 16.8% 18.1% 7.4%

A1-2
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1998 Pass - 18,315 0.23 3.22 0.62 0.23 3.22 0.62 0.0% 0.0% 0.0%

P Fail Pass 1,403 7.0% 0.87 12.43 1.39 0.26 3.52 0.70 70.1% 71.7% 50.0%

Fail Unresolv. 292 1.5% 1.72 19.58 2.19 0.54 6.53 0.71 68.4% 66.6% 67.7%

Fail Waiver 8 0.0% 2.17 35.25 3.35 1.85 36.38 2.59 14.5% -3.2% 22.7%

Total Fail% 20,018 8.5% 0.30 4.11 0.70 0.24 3.30 0.63 20.1% 19.8% 10.1%

1999 Pass - 22,938 0.20 2.89 0.57 0.20 2.89 0.57 0.0% 0.0% 0.0%

P Fail Pass 1,729 6.9% 0.66 10.25 1.25 0.21 2.74 0.65 68.2% 73.3% 48.5%

Fail Unresolv. 293 1.2% 1.58 22.61 2.34 0.48 6.88 0.80 69.7% 69.6% 66.0%

Fail Waiver 7 0.0% 1.08 7.69 3.34 0.89 6.08 3.30 18.0% 20.9% 1.2%

Total Fail% 24,967 8.1% 0.25 3.63 0.64 0.21 2.93 0.58 17.6% 19.4% 9.5%

2000 Pass - 21,581 0.16 2.69 0.50 0.16 2.69 0.50 0.0% 0.0% 0.0%

P Fail Pass 1,485 6.4% 0.62 8.17 1.42 0.18 2.76 0.56 71.1% 66.2% 60.9%

Fail Unresolv. 269 1.2% 1.53 14.33 2.61 0.40 4.22 0.88 73.8% 70.5% 66.2%

Fail Waiver 4 0.0% 0.84 5.95 3.64 0.84 16.22 2.07 -0.3% -172.5% 43.1%

Total Fail% 23,339 7.5% 0.21 3.17 0.59 0.17 2.71 0.51 19.7% 14.5% 12.8%

2001 Pass - 26,531 0.13 2.38 0.41 0.13 2.38 0.41 0.0% 0.0% 0.0%

P Fail Pass 1,051 3.8% 0.48 8.00 1.27 0.13 2.06 0.39 72.9% 74.2% 69.3%

Fail Unresolv. 129 0.5% 1.48 21.89 2.51 0.50 6.69 0.85 66.1% 69.4% 66.3%

Fail Waiver 2 0.0% 0.12 10.23 0.79 0.18 16.47 0.44 -44.9% -60.9% 44.8%

Total Fail% 27,713 4.3% 0.15 2.69 0.45 0.13 2.39 0.41 12.1% 11.0% 9.2%

2002 Pass - 20,396 0.12 2.27 0.37 0.12 2.27 0.37 0.0% 0.0% 0.0%

P Fail Pass 858 4.0% 0.41 6.15 1.08 0.11 2.34 0.34 73.6% 62.0% 68.4%

Fail Unresolv. 97 0.5% 1.35 19.93 2.82 0.39 6.35 0.87 71.0% 68.1% 69.0%

Fail Waiver 2 0.0% 0.19 8.27 2.57 0.48 6.27 3.44 -146.4% 24.2% -33.8%

Total Fail% 21,353 4.5% 0.14 2.51 0.41 0.12 2.29 0.37 12.2% 8.6% 9.3%

2003 Pass - 26,513 0.10 2.01 0.33 0.10 2.01 0.33 0.0% 0.0% 0.0%

P Fail Pass 764 2.8% 0.41 5.70 0.83 0.09 1.36 0.24 79.1% 76.1% 71.4%

Fail Unresolv. 50 0.2% 2.15 13.77 2.63 0.56 4.51 0.87 73.8% 67.3% 66.9%

Fail Waiver 2 0.0% 6.81 9.58 2.85 1.04 8.61 2.67 84.8% 10.2% 6.2%

Total Fail% 27,329 3.0% 0.11 2.13 0.35 0.10 1.99 0.33 11.1% 6.5% 5.7%

2004 Pass - 14,333 0.09 2.03 0.30 0.09 2.03 0.30 0.0% 0.0% 0.0%

P Fail Pass 623 4.2% 0.27 4.46 0.57 0.06 1.09 0.17 76.7% 75.6% 70.0%

Fail Unresolv. 32 0.2% 1.59 16.84 2.55 0.47 4.85 0.80 70.3% 71.2% 68.7%

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 14,988 4.4% 0.10 2.17 0.31 0.09 2.00 0.29 10.6% 7.6% 6.5%

2005 Pass - 29,578 0.09 1.86 0.28 0.09 1.86 0.28 0.0% 0.0% 0.0%

P Fail Pass 932 3.1% 0.25 3.82 0.56 0.05 0.92 0.13 81.2% 75.9% 77.2%

Fail Unresolv. 31 0.1% 1.50 15.93 2.80 0.42 4.87 0.83 72.1% 69.4% 70.5%

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 30,541 3.2% 0.09 1.94 0.29 0.09 1.84 0.27 7.8% 5.2% 5.3%

A1-3
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

2006 Pass - 8,185 0.08 1.86 0.26 0.08 1.86 0.26 0.0% 0.0% 0.0%

P Fail Pass 240 2.8% 0.19 3.04 1.82 0.06 0.92 0.17 66.6% 69.8% 90.6%

Fail Unresolv. 13 0.2% 0.69 6.38 2.47 0.23 2.10 0.90 66.7% 67.1% 63.4%

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 8,438 3.0% 0.09 1.90 0.30 0.08 1.83 0.25 5.1% 3.5% 16.3%

2007 Pass - 3,797 0.08 1.74 0.24 0.08 1.74 0.24 0.0% 0.0% 0.0%

P Fail Pass 118 3.0% 0.11 1.98 1.08 0.03 0.78 0.09 70.1% 60.6% 91.8%

Fail Unresolv. 10 0.3% 0.80 5.23 2.46 0.15 2.54 0.69 81.1% 51.4% 72.0%

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 3,925 3.3% 0.08 1.76 0.27 0.08 1.71 0.24 4.9% 2.4% 12.6%

2008 Pass - 2,943 0.08 1.85 0.23 0.08 1.85 0.23 0.0% 0.0% 0.0%

P Fail Pass 118 3.8% 0.09 1.86 0.83 0.03 0.78 0.09 66.6% 58.2% 89.6%

Fail Unresolv. 7 0.2% 0.06 1.42 1.12 0.02 0.47 0.37 67.0% 67.0% 67.0%

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 3,068 4.1% 0.08 1.85 0.25 0.08 1.81 0.22 3.1% 2.4% 11.9%

2009 Pass - 718 0.08 1.75 0.25 0.08 1.75 0.25 0.0% 0.0% 0.0%

P Fail Pass 17 2.3% 0.28 2.50 2.82 0.03 0.62 0.19 88.3% 75.1% 93.3%

Fail Unresolv. 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 735 2.3% 0.08 1.76 0.31 0.08 1.72 0.25 6.8% 2.5% 19.8%

2010 Pass - 32 0.07 1.82 0.24 0.07 1.82 0.24 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Fail Unresolv. 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 32 0.0% 0.07 1.82 0.24 0.07 1.82 0.24 0.0% 0.0% 0.0%

Total Passenger Vehicles

All Pass - 312,038 0.27 3.57 0.68 0.27 3.57 0.68 0.0% 0.0% 0.0%

P Fail Pass 22,374 6.6% 1.31 16.13 1.63 0.45 4.68 1.03 66.0% 71.0% 36.7%

Fail Unresolv. 6,072 1.8% 3.14 32.68 2.50 0.99 10.46 0.82 68.6% 68.0% 67.1%

Fail Waiver 148 0.0% 2.72 31.46 2.71 2.60 30.91 2.49 4.4% 1.8% 8.2%

Total Fail% 340,632 8.4% 0.39 4.93 0.78 0.29 3.78 0.71 24.7% 23.3% 8.9%

A1-4
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1982 Pass - 286 2.82 31.51 2.76 2.82 31.51 2.76 0.0% 0.0% 0.0%

T Fail Pass 158 31.0% 4.79 56.94 3.22 2.60 30.91 2.70 45.7% 45.7% 16.1%

Fail Unresolv. 66 12.9% 6.87 97.39 2.80 2.21 32.71 0.85 67.8% 66.4% 69.5%

Fail Waiver 0 0.0%

Total Fail% 510 43.9% 3.95 47.92 2.91 2.67 31.48 2.49 32.4% 34.3% 14.2%

1983 Pass - 598 2.86 32.43 2.66 2.86 32.43 2.66 0.0% 0.0% 0.0%

T Fail Pass 193 22.1% 4.14 54.95 3.29 2.54 27.65 2.86 38.6% 49.7% 13.1%

Fail Unresolv. 84 9.6% 7.76 108.44 2.62 2.24 34.75 0.83 71.1% 68.0% 68.2%

Fail Waiver 0 0.0%

Total Fail% 875 31.7% 3.61 44.70 2.80 2.73 31.60 2.53 24.4% 29.3% 9.5%

1984 Pass - 873 2.36 26.72 2.74 2.36 26.72 2.74 0.0% 0.0% 0.0%

T Fail Pass 362 25.7% 4.36 61.34 2.93 2.31 25.22 3.09 47.0% 58.9% -5.6%

Fail Unresolv. 167 11.9% 7.21 103.50 2.80 2.25 32.68 0.94 68.8% 68.4% 66.4%

Fail Waiver 7 0.5% 6.04 83.03 2.73 4.84 89.72 2.09 19.9% -8.1% 23.6%

Total Fail% 1,409 38.0% 3.47 45.00 2.80 2.35 27.35 2.61 32.3% 39.2% 6.5%

1985 Pass - 1,233 2.02 22.71 2.62 2.02 22.71 2.62 0.0% 0.0% 0.0%

T Fail Pass 489 25.2% 3.72 49.13 3.00 1.99 20.48 2.92 46.5% 58.3% 2.6%

Fail Unresolv. 212 10.9% 5.96 89.48 2.63 2.05 30.23 0.87 65.5% 66.2% 66.9%

Fail Waiver 3 0.2% 5.74 57.48 5.39 3.45 36.29 5.11 39.8% 36.9% 5.2%

Total Fail% 1,937 36.3% 2.88 36.74 2.72 2.02 22.99 2.51 30.1% 37.4% 7.8%

1986 Pass - 1,484 1.80 17.60 2.70 1.80 17.60 2.70 0.0% 0.0% 0.0%

T Fail Pass 460 21.3% 3.93 48.36 3.02 1.89 19.45 2.77 52.0% 59.8% 8.1%

Fail Unresolv. 211 9.8% 6.29 85.69 2.72 2.04 27.18 0.95 67.6% 68.3% 64.9%

Fail Waiver 4 0.2% 4.61 59.28 3.50 6.48 71.32 3.41 -40.7% -20.3% 2.7%

Total Fail% 2,159 31.3% 2.70 30.89 2.77 1.85 19.03 2.54 31.4% 38.4% 8.1%

1987 Pass - 2,195 1.48 14.22 2.32 1.48 14.22 2.32 0.0% 0.0% 0.0%

T Fail Pass 479 16.7% 2.94 37.31 2.79 1.47 13.98 2.54 49.8% 62.5% 9.1%

Fail Unresolv. 185 6.5% 4.79 61.17 2.80 1.60 20.18 0.94 66.7% 67.0% 66.2%

Fail Waiver 2 0.1% 6.16 56.18 2.10 6.98 30.01 3.07 -13.4% 46.6% -46.2%

Total Fail% 2,861 23.3% 1.94 21.15 2.43 1.49 14.58 2.27 23.2% 31.1% 6.7%

1988 Pass - 2,524 1.33 12.61 2.11 1.33 12.61 2.11 0.0% 0.0% 0.0%

T Fail Pass 620 18.2% 3.36 30.79 3.01 1.40 12.22 2.40 58.3% 60.3% 20.2%

Fail Unresolv. 255 7.5% 5.30 46.73 3.21 1.67 15.54 1.06 68.4% 66.7% 66.9%

Fail Waiver 3 0.1% 2.32 54.92 1.52 2.17 53.97 3.09 6.8% 1.7% -102.5%

Total Fail% 3,402 25.8% 2.00 18.52 2.36 1.37 12.80 2.09 31.5% 30.9% 11.5%

1989 Pass - 3,504 1.23 11.60 2.05 1.23 11.60 2.05 0.0% 0.0% 0.0%

T Fail Pass 735 16.3% 2.88 29.29 2.91 1.39 12.23 2.43 51.6% 58.2% 16.5%

Fail Unresolv. 254 5.6% 4.79 49.29 3.43 1.54 16.88 1.08 67.8% 65.7% 68.6%

Fail Waiver 9 0.2% 3.72 50.54 4.00 2.95 48.37 3.72 20.8% 4.3% 7.1%

Total Fail% 4,502 22.2% 1.70 16.69 2.27 1.27 12.07 2.06 25.1% 27.7% 9.3%

A1-5
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1990 Pass - 3,408 1.18 10.99 2.11 1.18 10.99 2.11 0.0% 0.0% 0.0%

T Fail Pass 689 16.0% 3.18 31.79 2.93 1.37 11.94 2.37 57.1% 62.4% 19.1%

Fail Unresolv. 216 5.0% 4.73 47.14 3.54 1.51 15.35 1.19 68.2% 67.4% 66.3%

Fail Waiver 3 0.1% 2.57 45.68 4.54 1.41 30.27 3.22 45.3% 33.7% 29.0%

Total Fail% 4,316 21.0% 1.68 16.14 2.32 1.23 11.37 2.11 26.9% 29.6% 9.0%

1991 Pass - 5,041 0.90 9.33 1.70 0.90 9.33 1.70 0.0% 0.0% 0.0%

T Fail Pass 882 14.2% 2.61 28.40 2.77 1.12 11.14 2.08 57.2% 60.8% 24.8%

Fail Unresolv. 280 4.5% 4.84 46.53 3.46 1.70 16.52 1.10 64.8% 64.5% 68.1%

Fail Waiver 4 0.1% 7.27 50.01 2.08 3.71 46.55 2.97 49.0% 6.9% -42.6%

Total Fail% 6,207 18.8% 1.32 13.74 1.93 0.97 9.93 1.73 26.9% 27.7% 10.5%

1992 Pass - 5,065 0.93 9.69 1.87 0.93 9.69 1.87 0.0% 0.0% 0.0%

T Fail Pass 905 14.4% 2.87 28.35 2.87 1.15 10.63 2.09 60.2% 62.5% 27.0%

Fail Unresolv. 311 4.9% 4.89 41.71 3.45 1.52 13.73 1.14 68.9% 67.1% 66.9%

Fail Waiver 5 0.1% 5.21 53.80 2.80 2.53 40.14 3.03 51.6% 25.4% -8.0%

Total Fail% 6,286 19.4% 1.41 14.00 2.09 0.99 10.05 1.86 29.7% 28.2% 10.8%

1993 Pass - 7,770 0.88 8.87 1.79 0.88 8.87 1.79 0.0% 0.0% 0.0%

T Fail Pass 1,276 13.6% 2.71 26.18 3.11 1.09 10.48 2.25 59.7% 60.0% 27.8%

Fail Unresolv. 349 3.7% 4.90 45.13 3.76 1.58 14.08 1.24 67.7% 68.8% 66.9%

Fail Waiver 14 0.1% 6.86 59.13 2.95 5.68 47.88 2.84 17.1% 19.0% 3.7%

Total Fail% 9,409 17.4% 1.29 12.63 2.04 0.95 9.34 1.83 26.7% 26.1% 10.3%

1994 Pass - 10,259 0.70 7.30 1.50 0.70 7.30 1.50 0.0% 0.0% 0.0%

T Fail Pass 1,691 13.6% 2.37 22.10 2.99 0.87 8.33 1.88 63.4% 62.3% 36.9%

Fail Unresolv. 495 4.0% 4.33 35.82 3.76 1.35 11.52 1.23 68.8% 67.8% 67.3%

Fail Waiver 16 0.1% 2.45 18.84 5.97 2.18 15.84 5.25 11.2% 16.0% 12.1%

Total Fail% 12,461 17.7% 1.07 10.45 1.79 0.75 7.61 1.54 30.2% 27.2% 14.0%

1995 Pass - 11,776 0.61 6.06 1.46 0.61 6.06 1.46 0.0% 0.0% 0.0%

T Fail Pass 1,943 13.6% 2.31 20.73 2.83 0.83 8.05 1.82 64.0% 61.2% 35.7%

Fail Unresolv. 498 3.5% 3.79 28.54 3.70 1.24 9.54 1.21 67.2% 66.6% 67.4%

Fail Waiver 21 0.1% 3.58 23.44 4.15 2.83 19.93 3.84 20.9% 15.0% 7.6%

Total Fail% 14,238 17.3% 0.96 8.87 1.73 0.67 6.47 1.50 30.4% 27.1% 13.0%

1996 Pass - 11,022 0.37 4.26 1.27 0.37 4.26 1.27 0.0% 0.0% 0.0%

T Fail Pass 1,543 12.0% 1.18 14.74 2.51 0.42 5.15 1.52 64.3% 65.0% 39.5%

Fail Unresolv. 336 2.6% 2.75 28.07 3.98 0.84 8.80 1.32 69.4% 68.7% 66.9%

Fail Waiver 10 0.1% 2.04 19.31 3.50 2.14 20.22 3.14 -5.0% -4.7% 10.1%

Total Fail% 12,911 14.6% 0.53 6.14 1.49 0.39 4.49 1.30 26.4% 26.8% 12.6%

1997 Pass - 15,797 0.31 3.85 1.11 0.31 3.85 1.11 0.0% 0.0% 0.0%

T Fail Pass 2,049 11.2% 1.01 13.91 2.20 0.38 4.87 1.35 62.4% 65.0% 38.8%

Fail Unresolv. 396 2.2% 2.45 25.30 3.53 0.82 8.65 1.17 66.6% 65.8% 66.8%

Fail Waiver 12 0.1% 1.19 32.81 3.51 0.98 33.49 3.36 17.5% -2.1% 4.3%

Total Fail% 18,254 13.5% 0.44 5.46 1.29 0.33 4.09 1.14 24.2% 25.2% 11.4%

A1-6
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1998 Pass - 16,789 0.29 3.28 0.96 0.29 3.28 0.96 0.0% 0.0% 0.0%

T Fail Pass 1,578 8.5% 0.94 10.94 2.09 0.36 4.18 1.18 62.1% 61.8% 43.8%

Fail Unresolv. 287 1.5% 2.21 20.63 3.58 0.63 6.05 1.17 71.6% 70.7% 67.4%

Fail Waiver 12 0.1% 1.35 22.76 3.28 1.94 25.36 3.14 -44.1% -11.4% 4.4%

Total Fail% 18,666 10.1% 0.38 4.21 1.10 0.30 3.42 0.98 19.5% 18.9% 10.5%

1999 Pass - 21,730 0.21 2.39 0.72 0.21 2.39 0.72 0.0% 0.0% 0.0%

T Fail Pass 1,816 7.6% 0.92 9.37 1.94 0.30 3.25 0.96 67.2% 65.3% 50.6%

Fail Unresolv. 257 1.1% 1.94 18.08 3.33 0.65 5.66 1.07 66.6% 68.7% 68.0%

Fail Waiver 8 0.0% 1.78 19.08 3.61 0.93 6.72 3.48 47.7% 64.8% 3.6%

Total Fail% 23,811 8.7% 0.29 3.10 0.84 0.23 2.50 0.74 21.4% 19.5% 11.8%

2000 Pass - 19,209 0.20 2.25 0.67 0.20 2.25 0.67 0.0% 0.0% 0.0%

T Fail Pass 1,363 6.6% 0.66 7.65 1.46 0.26 3.05 0.83 61.3% 60.1% 43.0%

Fail Unresolv. 115 0.6% 2.62 23.84 3.02 0.70 7.67 1.00 73.4% 67.8% 67.1%

Fail Waiver 5 0.0% 2.35 18.88 3.09 2.12 17.97 3.13 9.8% 4.9% -1.3%

Total Fail% 20,692 7.2% 0.24 2.73 0.74 0.20 2.33 0.68 15.5% 14.4% 7.1%

2001 Pass - 23,784 0.12 1.65 0.49 0.12 1.65 0.49 0.0% 0.0% 0.0%

T Fail Pass 1,231 4.9% 0.43 6.58 1.08 0.17 2.35 0.55 61.8% 64.3% 49.0%

Fail Unresolv. 77 0.3% 1.56 18.09 2.52 0.60 5.54 0.87 61.6% 69.4% 65.5%

Fail Waiver 1 0.0% 0.01 0.14 3.16 0.03 0.13 3.47 -136.5% 1.0% -9.8%

Total Fail% 25,093 5.2% 0.14 1.94 0.53 0.13 1.70 0.49 11.2% 12.7% 5.9%

2002 Pass - 17,493 0.10 1.48 0.45 0.10 1.48 0.45 0.0% 0.0% 0.0%

T Fail Pass 818 4.5% 0.28 6.14 0.90 0.13 2.11 0.47 55.8% 65.7% 48.0%

Fail Unresolv. 46 0.3% 1.09 21.61 2.61 0.38 7.87 0.87 65.1% 63.6% 66.5%

Fail Waiver 6 0.0% 1.68 33.42 3.16 1.34 30.01 2.91 20.1% 10.2% 7.7%

Total Fail% 18,363 4.7% 0.12 1.75 0.47 0.11 1.53 0.45 7.7% 12.3% 5.0%

2003 Pass - 25,323 0.09 1.25 0.38 0.09 1.25 0.38 0.0% 0.0% 0.0%

T Fail Pass 823 3.1% 0.26 4.28 0.71 0.10 1.51 0.35 62.2% 64.6% 49.8%

Fail Unresolv. 23 0.1% 0.87 8.20 3.08 0.28 3.04 0.94 67.9% 63.0% 69.6%

Fail Waiver 0 0.0%

Total Fail% 26,169 3.2% 0.10 1.36 0.39 0.09 1.26 0.38 5.8% 6.8% 3.3%

2004 Pass - 15,239 0.08 1.14 0.29 0.08 1.14 0.29 0.0% 0.0% 0.0%

T Fail Pass 493 3.1% 0.17 3.26 0.51 0.08 1.28 0.18 53.9% 60.8% 64.2%

Fail Unresolv. 19 0.1% 1.21 15.83 1.67 0.39 5.17 0.53 67.6% 67.4% 68.4%

Fail Waiver 0 0.0%

Total Fail% 15,751 3.3% 0.08 1.22 0.30 0.08 1.14 0.28 4.8% 6.1% 3.9%

2005 Pass - 31,394 0.06 0.98 0.22 0.06 0.98 0.22 0.0% 0.0% 0.0%

T Fail Pass 596 1.9% 0.16 3.04 0.34 0.05 0.96 0.12 65.4% 68.6% 64.7%

Fail Unresolv. 15 0.0% 0.18 5.39 0.54 0.06 1.80 0.18 67.1% 66.7% 67.2%

Fail Waiver 0 0.0%

Total Fail% 32,005 1.9% 0.07 1.02 0.22 0.06 0.98 0.22 3.0% 4.0% 1.9%

A1-7
Appendix A1 Colorado 2009 Transient Test Emissions Reductions

Unresolved fails remaining in area 33%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

2006 Pass - 7,019 0.06 0.94 0.21 0.06 0.94 0.21 0.0% 0.0% 0.0%

T Fail Pass 163 2.3% 0.18 1.64 0.82 0.07 0.88 0.14 59.9% 46.5% 82.5%

Fail Unresolv. 7 0.1% 0.50 3.59 1.66 0.16 1.19 0.55 67.0% 67.0% 67.0%

Fail Waiver 0 0.0%

Total Fail% 7,189 2.4% 0.06 0.96 0.23 0.06 0.94 0.21 4.3% 2.1% 7.2%

2007 Pass - 3,400 0.05 0.85 0.19 0.05 0.85 0.19 0.0% 0.0% 0.0%

T Fail Pass 69 2.0% 0.06 0.88 0.62 0.05 0.85 0.11 18.7% 3.5% 82.9%

Fail Unresolv. 3 0.1% 0.69 8.03 3.46 0.23 2.65 1.14 67.0% 67.0% 67.0%

Fail Waiver 0 0.0%

Total Fail% 3,472 2.1% 0.05 0.86 0.20 0.05 0.85 0.19 1.1% 0.6% 6.0%

2008 Pass - 2,700 0.05 0.81 0.20 0.05 0.81 0.20 0.0% 0.0% 0.0%

T Fail Pass 56 2.0% 0.05 0.90 0.44 0.03 0.71 0.06 37.8% 21.2% 87.4%

Fail Unresolv. 4 0.1% 0.17 1.43 0.41 0.06 0.47 0.14 67.0% 67.0% 67.0%

Fail Waiver 0 0.0%

Total Fail% 2,760 2.2% 0.05 0.81 0.20 0.05 0.81 0.19 1.1% 0.6% 4.1%

2009 Pass - 567 0.05 0.87 0.18 0.05 0.87 0.18 0.0% 0.0% 0.0%

T Fail Pass 8 1.4% 0.04 0.77 0.19 0.02 0.46 0.03 58.2% 40.5% 86.5%

Fail Unresolv. 0 0.0%

Fail Waiver 0 0.0%

Total Fail% 575 1.4% 0.05 0.87 0.18 0.05 0.86 0.18 0.6% 0.5% 1.3%

2010 Pass - 8 0.05 0.50 0.15 0.05 0.50 0.15 0.0% 0.0% 0.0%

T Fail Pass 0 0.0%

Fail Unresolv. 0 0.0%

Fail Waiver 0 0.0%

Total Fail% 8 0.0% 0.05 0.50 0.15 0.05 0.50 0.15 0.0% 0.0% 0.0%

Total Trucks

All Pass - 267,490 0.33 3.64 0.82 0.33 3.64 0.82 0.0% 0.0% 0.0%

T Fail Pass 23,488 7.9% 1.73 19.01 2.23 0.72 7.42 1.52 58.1% 61.0% 32.1%

Fail Unresolv. 5,168 1.7% 4.17 43.59 3.38 1.34 14.26 1.11 67.9% 67.3% 67.1%

Fail Waiver 145 0.0% 3.39 36.26 3.70 2.80 32.63 3.50 17.4% 10.0% 5.5%

Total Fail% 296,291 9.7% 0.51 5.57 0.98 0.38 4.14 0.89 25.3% 25.7% 9.8%

Fleet Total

All Pass - 579,528 0.30 3.60 0.75 0.30 3.60 0.75 0.0% 0.0% 0.0%

All Fail Pass 45,862 7.2% 1.52 17.61 1.94 0.59 6.08 1.28 61.4% 65.5% 34.0%

Fail Unresolv. 11,240 1.8% 3.61 37.70 2.90 1.15 12.21 0.95 68.2% 67.6% 67.1%

Fail Waiver 293 0.0% 3.05 33.84 3.20 2.69 31.76 2.99 11.6% 6.1% 6.7%

Total Fail% 636,923 9.0% 0.44 5.23 0.87 0.33 3.95 0.79 25.0% 24.5% 9.4%

A1-8
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1982 Pass - 0 ------ - - -

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

1983 Pass - 1 0.75 7.40 1.19 0.75 7.40 1.19 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 1 0.0% 0.75 7.40 1.19 0.75 7.40 1.19 0.0% 0.0% 0.0%

1984 Pass - 1 1.18 10.90 2.85 1.18 10.90 2.85 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 1 0.0% 1.18 10.90 2.85 1.18 10.90 2.85 0.0% 0.0% 0.0%

1985 Pass - 0 ------ - - -

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

1986 Pass - 5 0.67 9.02 1.74 0.67 9.02 1.74 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 5 0.0% 0.67 9.02 1.74 0.67 9.02 1.74 0.0% 0.0% 0.0%

1987 Pass - 4 0.83 9.59 2.68 0.83 9.59 2.68 0.0% 0.0% 0.0%

P Fail Pass 1 16.7% 0.31 6.64 1.89 0.37 8.58 0.79 -18.1% -29.2% 58.0%

Fail Unresolv. 1 16.7% 2.01 14.10 4.24 0.53 2.20 4.18 73.6% 84.4% 1.4%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 6 33.3% 0.94 9.85 2.81 0.70 8.19 2.62 25.2% 16.9% 6.9%

1988 Pass - 3 0.48 8.22 1.78 0.48 8.22 1.78 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 1 25.0% 2.71 10.93 3.74 2.69 11.04 3.23 0.6% -1.0% 13.5%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 4 25.0% 1.04 8.89 2.27 1.03 8.92 2.14 0.4% -0.3% 5.6%

1989 Pass - 8 0.96 8.36 1.99 0.96 8.36 1.99 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 8 0.0% 0.96 8.36 1.99 0.96 8.36 1.99 0.0% 0.0% 0.0%

A2-1
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1990 Pass - 13 0.64 7.56 1.63 0.64 7.56 1.63 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 13 0.0% 0.64 7.56 1.63 0.64 7.56 1.63 0.0% 0.0% 0.0%

1991 Pass - 17 0.46 6.15 1.28 0.46 6.15 1.28 0.0% 0.0% 0.0%

P Fail Pass 1 5.6% 2.41 49.71 2.11 0.61 2.94 1.82 74.9% 94.1% 13.4%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 18 5.6% 0.57 8.57 1.32 0.47 5.98 1.31 17.5% 30.3% 1.2%

1992 Pass - 13 0.48 5.48 1.36 0.48 5.48 1.36 0.0% 0.0% 0.0%

P Fail Pass 3 17.6% 0.70 17.17 0.95 0.51 6.54 1.31 27.5% 61.9% -37.1%

Fail Unresolv. 1 5.9% 0.26 5.36 4.08 2.09 47.38 0.38 -713.7% -784.6% 90.7%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 17 23.5% 0.51 7.54 1.45 0.58 8.13 1.29 -14.5% -7.9% 10.7%

1993 Pass - 33 0.45 4.99 1.41 0.45 4.99 1.41 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 33 0.0% 0.45 4.99 1.41 0.45 4.99 1.41 0.0% 0.0% 0.0%

1994 Pass - 38 0.33 3.70 1.02 0.33 3.70 1.02 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 38 0.0% 0.33 3.70 1.02 0.33 3.70 1.02 0.0% 0.0% 0.0%

1995 Pass - 40 0.30 3.63 0.82 0.30 3.63 0.82 0.0% 0.0% 0.0%

P Fail Pass 1 2.4% 0.23 7.28 3.02 1.00 3.05 2.33 -324.0% 58.1% 22.8%

Fail Unresolv. 1 2.4% 7.41 10.20 1.54 7.41 10.20 1.54 0.0% 0.0% 0.0%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 42 4.8% 0.47 3.87 0.89 0.48 3.77 0.88 -3.9% 2.6% 1.8%

1996 Pass - 55 0.26 2.93 0.79 0.26 2.93 0.79 0.0% 0.0% 0.0%

P Fail Pass 2 3.5% 0.82 4.05 2.61 0.14 2.38 0.79 82.7% 41.3% 69.7%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 57 3.5% 0.28 2.97 0.85 0.26 2.91 0.79 8.4% 2.0% 7.5%

1997 Pass - 79 0.22 2.76 0.62 0.22 2.76 0.62 0.0% 0.0% 0.0%

P Fail Pass 2 2.5% 0.12 2.14 0.32 0.34 1.78 1.00 -179.2% 17.1% -217.8%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 81 2.5% 0.22 2.75 0.61 0.22 2.74 0.63 -2.5% 0.3% -2.8%

A2-2
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1998 Pass - 94 0.23 2.80 0.63 0.23 2.80 0.63 0.0% 0.0% 0.0%

P Fail Pass 2 2.1% 0.25 10.33 2.30 0.48 3.19 1.07 -93.6% 69.1% 53.8%

Fail Unresolv. 1 1.0% 0.06 0.22 3.11 0.06 0.22 3.11 0.0% 0.0% 0.0%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 97 3.1% 0.23 2.93 0.69 0.23 2.78 0.66 -2.1% 5.0% 3.7%

1999 Pass - 151 0.23 2.70 0.61 0.23 2.70 0.61 0.0% 0.0% 0.0%

P Fail Pass 8 5.0% 0.53 3.80 0.82 0.27 1.99 0.65 48.2% 47.6% 21.7%

Fail Unresolv. 1 0.6% 1.54 74.71 1.66 1.54 74.71 1.66 0.0% 0.0% 0.0%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 160 5.6% 0.25 3.21 0.63 0.24 3.12 0.62 5.1% 2.8% 1.4%

2000 Pass - 165 0.17 2.74 0.49 0.17 2.74 0.49 0.0% 0.0% 0.0%

P Fail Pass 9 5.1% 0.35 5.60 1.98 0.12 2.54 0.46 66.3% 54.7% 76.5%

Fail Unresolv. 2 1.1% 1.83 13.35 1.76 1.85 13.76 1.89 -1.1% -3.1% -7.0%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 176 6.3% 0.20 3.01 0.58 0.18 2.86 0.50 5.9% 5.1% 13.1%

2001 Pass - 179 0.11 2.17 0.37 0.11 2.17 0.37 0.0% 0.0% 0.0%

P Fail Pass 7 3.8% 0.09 2.31 0.25 0.07 0.77 0.26 21.1% 66.9% -4.8%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 186 3.8% 0.11 2.18 0.36 0.11 2.12 0.37 0.6% 2.7% -0.1%

2002 Pass - 136 0.11 2.20 0.36 0.11 2.20 0.36 0.0% 0.0% 0.0%

P Fail Pass 5 3.5% 0.32 3.58 1.05 0.08 2.18 0.61 74.5% 39.2% 41.9%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 141 3.5% 0.12 2.24 0.38 0.11 2.19 0.37 7.2% 2.2% 4.1%

2003 Pass - 264 0.10 1.96 0.31 0.10 1.96 0.31 0.0% 0.0% 0.0%

P Fail Pass 10 3.6% 0.09 2.14 0.32 0.03 0.76 0.29 65.7% 64.7% 11.0%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 274 3.6% 0.10 1.97 0.31 0.10 1.92 0.31 2.2% 2.6% 0.4%

2004 Pass - 94 0.09 2.13 0.31 0.09 2.13 0.31 0.0% 0.0% 0.0%

P Fail Pass 2 2.1% 0.04 1.02 0.86 0.03 0.10 0.01 39.0% 90.5% 98.3%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 96 2.1% 0.09 2.11 0.32 0.09 2.09 0.31 0.4% 0.9% 5.4%

2005 Pass - 315 0.08 1.90 0.27 0.08 1.90 0.27 0.0% 0.0% 0.0%

P Fail Pass 12 3.7% 0.09 1.46 0.43 0.02 0.23 0.09 71.2% 84.5% 77.8%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 327 3.7% 0.08 1.88 0.28 0.08 1.84 0.27 2.6% 2.4% 4.4%

2006 Pass - 3 0.10 2.27 0.29 0.10 2.27 0.29 0.0% 0.0% 0.0%

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 3 0.0% 0.10 2.27 0.29 0.10 2.27 0.29 0.0% 0.0% 0.0%

A2-3
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

2007 Pass - 0 ------ - - -

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

2008 Pass - 0 ------ - - -

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

2009 Pass - 0 ------ - - -

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

2010 Pass - 0 ------ - - -

P Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

Total Passenger Vehicles

All Pass - 1,711 0.17 2.59 0.50 0.17 2.59 0.50 0.0% 0.0% 0.0%

P Fail Pass 65 3.6% 0.29 4.68 0.95 0.16 1.76 0.50 46.2% 62.4% 46.9%

Fail Unresolv. 8 0.4% 2.21 17.78 2.74 2.25 21.66 2.23 -2.1% -21.8% 18.3%

Fail Waiver 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00

Total Fail% 1,784 4.1% 0.18 2.73 0.53 0.18 2.65 0.51 2.6% 3.3% 3.5%

A2-4
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1982 Pass - 2 2.13 31.73 2.57 2.13 31.73 2.57 0.0% 0.0% 0.0%

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 2 0.0% 2.13 31.73 2.57 2.13 31.73 2.57 0.0% 0.0% 0.0%

1983 Pass - 0 ------ - - -

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

1984 Pass - 0 ------ - - -

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

1985 Pass - 0 ------ - - -

T Fail Pass 1 100.0% 0.33 3.18 6.20 0.38 4.00 4.98 -17.7% -25.7% 19.7%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 1 100.0% 0.33 3.18 6.20 0.38 4.00 4.98 -17.7% -25.7% 19.7%

1986 Pass - 0 ------ - - -

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

1987 Pass - 6 1.00 11.40 2.00 1.00 11.40 2.00 0.0% 0.0% 0.0%

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 6 0.0% 1.00 11.40 2.00 1.00 11.40 2.00 0.0% 0.0% 0.0%

1988 Pass - 1 0.98 10.91 2.32 0.98 10.91 2.32 0.0% 0.0% 0.0%

T Fail Pass 1 50.0% 1.57 11.73 5.23 1.80 12.44 4.06 -14.6% -6.1% 22.3%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 2 50.0% 1.28 11.32 3.78 1.39 11.67 3.19 -9.0% -3.2% 15.4%

1989 Pass - 2 1.64 11.40 2.14 1.64 11.40 2.14 0.0% 0.0% 0.0%

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 2 0.0% 1.64 11.40 2.14 1.64 11.40 2.14 0.0% 0.0% 0.0%

1990 Pass - 3 0.62 8.95 1.28 0.62 8.95 1.28 0.0% 0.0% 0.0%

T Fail Pass 1 25.0% 2.52 33.29 13.25 1.33 10.13 1.78 47.3% 69.6% 86.6%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 4 25.0% 1.09 15.04 4.27 0.80 9.25 1.40 27.2% 38.5% 67.1%

A2-5
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

1991 Pass - 8 0.68 7.19 1.78 0.68 7.19 1.78 0.0% 0.0% 0.0%

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 8 0.0% 0.68 7.19 1.78 0.68 7.19 1.78 0.0% 0.0% 0.0%

1992 Pass - 8 0.76 9.48 1.54 0.76 9.48 1.54 0.0% 0.0% 0.0%

T Fail Pass 1 11.1% 2.22 18.58 1.55 1.03 22.94 1.58 53.6% -23.5% -2.3%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 9 11.1% 0.92 10.49 1.54 0.79 10.98 1.54 14.3% -4.6% -0.3%

1993 Pass - 15 0.68 6.98 1.57 0.68 6.98 1.57 0.0% 0.0% 0.0%

T Fail Pass 2 11.8% 1.47 40.81 0.96 1.01 11.95 1.40 31.2% 70.7% -45.6%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 17 11.8% 0.77 10.96 1.50 0.72 7.56 1.55 7.0% 31.0% -3.4%

1994 Pass - 29 0.70 6.19 1.44 0.70 6.19 1.44 0.0% 0.0% 0.0%

T Fail Pass 1 3.3% 1.30 2.64 8.00 0.55 8.19 3.24 57.5% -210.2% 59.5%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 30 3.3% 0.72 6.08 1.66 0.69 6.26 1.50 3.5% -3.0% 9.6%

1995 Pass - 36 0.55 5.33 1.52 0.55 5.33 1.52 0.0% 0.0% 0.0%

T Fail Pass 6 14.0% 2.17 11.97 2.05 0.59 4.92 1.94 72.7% 58.9% 5.3%

Fail Unresolv. 1 2.3% 5.73 67.23 0.05 5.73 67.23 0.05 0.0% 0.0% 0.0%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 43 16.3% 0.89 7.69 1.56 0.67 6.71 1.54 24.7% 12.8% 1.0%

1996 Pass - 35 0.39 4.28 1.39 0.39 4.28 1.39 0.0% 0.0% 0.0%

T Fail Pass 3 7.7% 0.30 8.70 2.01 0.37 5.21 2.08 -23.7% 40.1% -3.4%

Fail Unresolv. 1 2.6% 1.32 12.48 3.17 1.46 13.97 3.21 -10.1% -12.0% -1.2%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 39 10.3% 0.41 4.83 1.49 0.42 4.60 1.49 -2.2% 4.8% -0.4%

1997 Pass - 75 0.34 3.85 1.21 0.34 3.85 1.21 0.0% 0.0% 0.0%

T Fail Pass 9 10.5% 0.42 5.09 2.19 0.31 4.92 1.65 25.8% 3.3% 24.8%

Fail Unresolv. 2 2.3% 1.61 13.09 4.37 1.30 11.26 4.87 19.3% 13.9% -11.3%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 86 12.8% 0.38 4.20 1.39 0.36 4.14 1.34 4.9% 1.4% 3.3%

1998 Pass - 104 0.25 2.92 0.86 0.25 2.92 0.86 0.0% 0.0% 0.0%

T Fail Pass 6 5.5% 0.38 4.06 1.84 0.29 3.08 1.13 25.4% 24.1% 38.8%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 110 5.5% 0.26 2.98 0.91 0.25 2.93 0.88 2.1% 1.8% 4.2%

1999 Pass - 194 0.20 2.01 0.73 0.20 2.01 0.73 0.0% 0.0% 0.0%

T Fail Pass 9 4.4% 0.39 3.69 1.17 0.34 2.73 0.85 13.1% 26.2% 26.7%

Fail Unresolv. 1 0.5% 1.60 40.42 2.53 2.01 48.78 2.66 -25.1% -20.7% -4.9%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 204 4.9% 0.21 2.27 0.76 0.21 2.27 0.75 0.1% 0.1% 1.7%

A2-6
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

2000 Pass - 170 0.20 2.09 0.71 0.20 2.09 0.71 0.0% 0.0% 0.0%

T Fail Pass 8 4.5% 0.31 3.30 1.32 0.28 3.06 1.17 7.6% 7.2% 11.4%

Fail Unresolv. 1 0.6% 0.51 6.61 2.29 0.53 5.14 2.20 -3.9% 22.2% 4.1%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 179 5.0% 0.20 2.17 0.75 0.20 2.15 0.74 0.5% 0.9% 1.0%

2001 Pass - 247 0.11 1.51 0.50 0.11 1.51 0.50 0.0% 0.0% 0.0%

T Fail Pass 7 2.7% 0.21 1.94 1.10 0.15 1.79 0.93 26.2% 7.6% 15.1%

Fail Unresolv. 1 0.4% 0.12 15.05 0.27 0.12 15.05 0.27 0.0% 0.0% 0.0%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 255 3.1% 0.12 1.58 0.51 0.11 1.57 0.51 1.3% 0.3% 0.9%

2002 Pass - 180 0.10 1.37 0.47 0.10 1.37 0.47 0.0% 0.0% 0.0%

T Fail Pass 3 1.6% 0.06 0.76 0.73 0.03 0.05 0.28 54.0% 93.6% 61.5%

Fail Unresolv. 1 0.5% 0.21 4.11 2.18 0.21 4.11 2.18 0.0% 0.0% 0.0%

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 184 2.2% 0.10 1.38 0.48 0.10 1.36 0.48 0.5% 0.8% 1.5%

2003 Pass - 345 0.09 1.20 0.37 0.09 1.20 0.37 0.0% 0.0% 0.0%

T Fail Pass 10 2.8% 0.10 1.59 0.32 0.05 1.15 0.26 45.3% 27.6% 18.4%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 355 2.8% 0.09 1.21 0.36 0.08 1.20 0.36 1.4% 1.0% 0.5%

2004 Pass - 124 0.07 1.04 0.27 0.07 1.04 0.27 0.0% 0.0% 0.0%

T Fail Pass 6 4.6% 0.08 1.17 0.35 0.04 0.83 0.09 49.0% 29.3% 72.7%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 130 4.6% 0.07 1.04 0.27 0.07 1.03 0.26 2.5% 1.5% 4.2%

2005 Pass - 424 0.06 0.90 0.21 0.06 0.90 0.21 0.0% 0.0% 0.0%

T Fail Pass 12 2.8% 0.08 0.79 0.26 0.04 0.38 0.07 46.6% 51.8% 71.8%

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 436 2.8% 0.06 0.90 0.21 0.06 0.89 0.21 1.7% 1.3% 2.4%

2006 Pass - 1 0.03 0.00 0.16 0.03 0.00 0.16 0.0% - 0.0%

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 1 0.0% 0.03 0.00 0.16 0.03 0.00 0.16 0.0% 0.0% 0.0%

2007 Pass - 0 ------ - - -

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

2008 Pass - 0 ------ - - -

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

A2-7
Appendix A2 Colorado 2009 Clean Screen Audit Transient Test Emissions Reductions

Unresolved fails remaining in area 100%

Model First Last Initial Final Reduction %

Year/Type Result Result Vehicles Fail% HC CO NOX HC CO NOX HC CO NOX

2009 Pass - 0 ------ - - -

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

2010 Pass - 0 ------ - - -

T Fail Pass 0 0.0% - - - - - - - - -

Fail Unresolv. 0 0.0% - - - - - - - - -

Fail Waiver 0 0.0% - - - - - - - - -

Total Fail% 0 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.0% 0.0% 0.0%

Total Trucks

All Pass - 2,009 0.16 1.91 0.56 0.16 1.91 0.56 0.0% 0.0% 0.0%

T Fail Pass 86 4.1% 0.48 4.96 1.45 0.28 3.17 1.00 41.1% 36.2% 30.6%

Fail Unresolv. 8 0.4% 1.59 21.51 2.41 1.58 22.10 2.54 0.5% -2.8% -5.5%

Fail Waiver 0 0.0%

Total Fail% 2,103 4.5% 0.18 2.11 0.60 0.17 2.04 0.58 4.5% 3.4% 2.9%

Fleet Total

All Pass - 3,720 0.17 2.22 0.53 0.17 2.22 0.53 0.0% 0.0% 0.0%

All Fail Pass 151 3.9% 0.40 4.84 1.23 0.23 2.56 0.79 42.7% 47.1% 36.0%

Fail Unresolv. 16 0.4% 1.90 19.64 2.57 1.92 21.88 2.39 -1.0% -11.4% 7.2%

Fail Waiver 0 0.0%

Total Fail% 3,887 4.3% 0.18 2.40 0.57 0.18 2.32 0.55 3.6% 3.3% 3.2%

A2-8
Appendix B Colorado 2009

Enhanced IM240 Test Reduction Tons

Initial Tons/Yr Final Tons/Yr Reduction Tons/Yr

Type

 Annual 

Miles 

 Unique 

Vehicles HC CO NOx HC CO NOx HC CO NOx

P 1982 4,434 433 5.4 58.6 4.4 3.7 42.2 4.1 1.6 16.4 0.3

P 1983 4,481 898 9.3 123.3 8.8 6.3 75.9 8.4 2.9 47.4 0.4

P 1984 4,502 1,333 13.3 160.3 13.3 9.1 100.3 12.5 4.1 60.0 0.8

P 1985 4,552 2,162 17.5 211.5 21.8 11.8 129.5 20.0 5.7 82.0 1.9

P 1986 4,780 2,323 17.5 198.6 24.4 12.2 126.4 22.8 5.2 72.1 1.6

P 1987 5,088 3,601 26.3 294.0 37.6 18.9 194.4 34.8 7.4 99.6 2.9

P 1988 5,430 3,787 27.9 314.4 40.2 19.5 212.9 37.2 8.3 101.5 3.0

P 1989 5,672 5,857 40.0 466.2 60.1 28.6 325.2 56.2 11.5 140.9 3.9

P 1990 6,002 7,406 51.7 573.8 83.0 37.4 404.9 75.5 14.3 168.9 7.5

P 1991 6,331 10,427 63.3 709.8 111.4 45.5 518.2 100.9 17.8 191.7 10.5

P 1992 6,653 10,053 62.0 721.4 110.8 43.4 487.2 100.6 18.6 234.3 10.3

P 1993 6,974 13,266 79.7 873.2 148.1 55.7 606.9 134.8 24.0 266.3 13.3

P 1994 7,369 14,614 75.2 836.6 141.8 52.1 612.3 128.1 23.0 224.3 13.7

P 1995 7,764 18,939 91.4 975.7 177.0 65.3 723.4 159.3 26.2 252.3 17.7

P 1996 8,188 17,023 63.7 739.5 139.8 49.7 583.8 126.6 14.0 155.7 13.2

P 1997 8,613 22,064 74.4 908.9 172.0 61.9 744.1 159.3 12.5 164.7 12.7

P 1998 9,032 20,018 59.8 819.8 139.2 47.8 657.5 125.1 12.0 162.2 14.1

P 1999 9,450 24,967 65.3 944.1 165.5 53.8 760.7 149.9 11.5 183.4 15.7

P 2000 9,905 23,339 53.0 808.1 149.5 42.6 691.2 130.3 10.4 116.9 19.2

P 2001 10,360 27,713 46.6 851.1 141.7 41.0 757.6 128.6 5.6 93.5 13.0

P 2002 10,746 21,353 34.4 633.8 104.5 30.3 579.4 94.8 4.2 54.4 9.7

P 2003 11,132 27,329 37.4 715.1 116.6 33.3 668.7 109.9 4.1 46.4 6.7

P 2004 11,870 14,988 20.4 424.8 61.4 18.2 392.3 57.4 2.2 32.5 4.0

P 2005 12,023 30,541 37.6 783.7 117.4 34.7 743.3 111.2 2.9 40.4 6.2

P 2006 12,307 8,438 9.9 217.6 34.7 9.4 209.9 29.0 0.5 7.7 5.6

P 2007 12,357 3,925 4.3 94.0 14.5 4.1 91.7 12.7 0.2 2.3 1.8

P 2008 11,600 3,068 3.1 72.7 10.0 3.0 70.9 8.8 0.1 1.7 1.2

P 2009 9,650 735 0.6 13.8 2.4 0.6 13.4 1.9 0.0 0.3 0.5

P 2010 9,650 32 0.0 0.6 0.1 0.0 0.6 0.1 0.0 0.0 0.0

P Total 340,632 1091.1 14544.9 2351.9 839.9 11525.1 2140.6 251.1 3019.8 211.3

T 1982 4 583 , 510 10 2. 123 4. 7 5. 6 9. 81 1. 6 4. 3 3. 42 3. 1 1.

T 1983 4,630 875 16.1 199.6 12.5 12.2 141.1 11.3 3.9 58.5 1.2

T 1984 4,668 1,409 25.1 326.2 20.3 17.0 198.3 19.0 8.1 127.9 1.3

T 1985 4,741 1,937 29.2 371.9 27.5 20.4 232.8 25.4 8.8 139.2 2.2

T 1986 4,851 2,159 31.2 356.6 32.0 21.4 219.7 29.4 9.8 136.9 2.6

T 1987 5,019 2,861 30.7 334.8 38.4 23.6 230.8 35.9 7.1 104.1 2.6

T 1988 5,256 3,402 39.4 365.0 46.4 27.0 252.2 41.1 12.4 112.8 5.3

T 1989 5,519 4,502 46.6 457.2 62.2 34.9 330.7 56.4 11.7 126.5 5.8

T 1990 5,824 4,316 46.6 447.2 64.2 34.1 315.1 58.4 12.5 132.2 5.8

T 1991 6,135 6,207 55.5 576.8 81.0 40.6 416.9 72.5 15.0 159.9 8.5

T 1992 6,471 6,286 63.2 627.6 93.7 44.4 450.6 83.6 18.7 177.0 10.1

T 1993 6,940 9,409 92.8 909.4 147.0 68.1 672.0 131.9 24.8 237.4 15.2

T 1994 7,437 12,461 109.4 1067.7 183.3 76.4 777.8 157.7 33.0 289.9 25.6

T 1995 7,863 14,238 118.4 1095.0 213.5 82.4 798.7 185.6 36.0 296.3 27.8

T 1996 8,345 12,911 63.1 729.2 176.9 46.4 533.7 154.5 16.7 195.6 22.3

T 1997 8,900 18,254 78.6 978.7 230.7 59.6 732.3 204.4 19.0 246.3 26.3

T 1998 9,502 18,666 73.3 822.9 214.3 59.0 667.7 191.9 14.3 155.2 22.4

T 1999 10,087 23,811 76.0 821.0 222.6 59.7 660.8 196.3 16.3 160.1 26.3

T 2000 10,727 20,692 59.1 667.1 180.2 50.0 571.0 167.3 9.2 96.2 12.8

T 2001 11,245 25,093 44.9 604.4 163.5 39.9 527.9 153.8 5.0 76.5 9.6

T 2002 11,817 18,363 27.6 417.8 113.4 25.4 366.3 107.7 2.1 51.5 5.7

T 2003 12,303 26,169 34.2 481.0 138.5 32.2 448.5 133.9 2.0 32.5 4.6

T 2004 12,834 15,751 18.0 271.7 66.0 17.1 255.0 63.4 0.9 16.7 2.6

T 2005 13,215 32,005 30.6 474.9 104.1 29.7 456.0 102.1 0.9 18.9 2.0

T 2006 13,433 7,189 6.9 101.7 24.1 6.6 99.7 22.4 0.3 2.1 1.7

T 2007 13,514 3,472 2.8 44.4 10.6 2.8 44.1 9.9 0.0 0.3 0.6

T 2008 12,428 2,760 1.8 30.8 7.6 1.8 30.6 7.3 0.0 0.2 0.3

T 2009 8,995 575 0.3 4.9 1.0 0.3 4.9 1.0 0.0 0.0 0.0

T 2010 8,995 8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T Total 296,291 1231.7 13709.1 2682.9 939.9 10516.3 2430.5 291.8 3192.7 252.4

Total 636,923 2322.7 28254.0 5034.8 1779.8 22041.4 4571.1 542.9 6212.5 463.7

B-1
Appendix B - Colorado 2009

RapidScreen Audit IM240 Test Reduction Tons

Initial Tons/Yr Final Tons/Yr Reduction Tons/Yr

Type

 Annual 

Miles 

 Unique 

Vehicles HC CO NOx HC CO NOx HC CO NOx

P 1982 4,434 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

P 1983 4,481 1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

P 1984 4,502 1 0.0 0.1 0.0 0.0 0.1 0.0 0.0 0.0 0.0

P 1985 4,552 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

P 1986 4,780 5 0.0 0.2 0.0 0.0 0.2 0.0 0.0 0.0 0.0

P 1987 5,088 6 0.0 0.3 0.1 0.0 0.3 0.1 0.0 0.1 0.0

P 1988 5,430 4 0.0 0.2 0.1 0.0 0.2 0.1 0.0 0.0 0.0

P 1989 5,672 8 0.0 0.4 0.1 0.0 0.4 0.1 0.0 0.0 0.0

P 1990 6,002 13 0.1 0.7 0.1 0.1 0.7 0.1 0.0 0.0 0.0

P 1991 6,331 18 0.1 1.1 0.2 0.1 0.8 0.2 0.0 0.3 0.0

P 1992 6,653 17 0.1 0.9 0.2 0.1 1.0 0.2 0.0 -0.1 0.0

P 1993 6,974 33 0.1 1.3 0.4 0.1 1.3 0.4 0.0 0.0 0.0

P 1994 7,369 38 0.1 1.1 0.3 0.1 1.1 0.3 0.0 0.0 0.0

P 1995 7,764 42 0.2 1.4 0.3 0.2 1.4 0.3 0.0 0.0 0.0

P 1996 8,188 57 0.1 1.5 0.4 0.1 1.5 0.4 0.0 0.0 0.0

P 1997 8,613 81 0.2 2.1 0.5 0.2 2.1 0.5 0.0 0.0 0.0

P 1998 9,032 97 0.2 2.8 0.7 0.2 2.7 0.6 0.0 0.1 0.0

P 1999 9,450 160 0.4 5.3 1.0 0.4 5.2 1.0 0.0 0.2 0.0

P 2000 9,905 176 0.4 5.8 1.1 0.4 5.5 1.0 0.0 0.3 0.1

P 2001 10,360 186 0.2 4.6 0.8 0.2 4.5 0.8 0.0 0.1 0.0

P 2002 10,746 141 0.2 3.7 0.6 0.2 3.7 0.6 0.0 0.1 0.0

P 2003 11,132 274 0.3 6.6 1.0 0.3 6.4 1.0 0.0 0.2 0.0

P 2004 11,870 96 0.1 2.6 0.4 0.1 2.6 0.4 0.0 0.0 0.0

P 2005 12,023 327 0.4 8.2 1.2 0.4 8.0 1.2 0.0 0.2 0.1

P 2006 12,307 3 0.0 0.1 0.0 0.0 0.1 0.0 0.0 0.0 0.0

P 2007 12,357 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

P 2008 11,600 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

P 2009 9,650 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

P Total 1,784 3.3 51.2 9.6 3.2 49.7 9.3 0.1 1.6 0.3

T 1982 4 583 , 2 0 0. 0 3. 0 0. 0 0. 0 3. 0 0. 0 0. 0 0. 0 0.

T 1983 4,630 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T 1984 4,668 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T 1985 4,741 1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T 1986 4,851 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T 1987 5,019 6 0.0 0.4 0.1 0.0 0.4 0.1 0.0 0.0 0.0

T 1988 5,256 2 0.0 0.1 0.0 0.0 0.1 0.0 0.0 0.0 0.0

T 1989 5,519 2 0.0 0.1 0.0 0.0 0.1 0.0 0.0 0.0 0.0

T 1990 5,824 4 0.0 0.4 0.1 0.0 0.2 0.0 0.0 0.1 0.1

T 1991 6,135 8 0.0 0.4 0.1 0.0 0.4 0.1 0.0 0.0 0.0

T 1992 6,471 9 0.1 0.7 0.1 0.1 0.7 0.1 0.0 0.0 0.0

T 1993 6,940 17 0.1 1.4 0.2 0.1 1.0 0.2 0.0 0.4 0.0

T 1994 7,437 30 0.2 1.5 0.4 0.2 1.5 0.4 0.0 0.0 0.0

T 1995 7,863 43 0.3 2.9 0.6 0.3 2.5 0.6 0.1 0.4 0.0

T 1996 8,345 39 0.1 1.7 0.5 0.2 1.6 0.5 0.0 0.1 0.0

T 1997 8,900 86 0.3 3.5 1.2 0.3 3.5 1.1 0.0 0.1 0.0

T 1998 9,502 110 0.3 3.4 1.1 0.3 3.4 1.0 0.0 0.1 0.0

T 1999 10,087 204 0.5 5.1 1.7 0.5 5.1 1.7 0.0 0.0 0.0

T 2000 10,727 179 0.4 4.6 1.6 0.4 4.6 1.6 0.0 0.0 0.0

T 2001 11,245 255 0.4 5.0 1.6 0.4 5.0 1.6 0.0 0.0 0.0

T 2002 11,817 184 0.2 3.3 1.2 0.2 3.3 1.1 0.0 0.0 0.0

T 2003 12,303 355 0.4 5.8 1.8 0.4 5.8 1.7 0.0 0.1 0.0

T 2004 12,834 130 0.1 1.9 0.5 0.1 1.9 0.5 0.0 0.0 0.0

T 2005 13,215 436 0.4 5.7 1.3 0.4 5.6 1.3 0.0 0.1 0.0

T 2006 13,433 1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T 2007 13,514 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T 2008 12,428 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T 2009 8,995 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

T Total 2,103 4.0 48.4 14.1 3.9 47.1 13.8 0.2 1.3 0.3

Total 3,887 7.3 99.7 23.7 7.1 96.8 23.1 0.2 2.9 0.7

B-2