EPA420-R-93-018

Guidance for the Implementation of

Accelerated Retirement of Vehicles Programs

Environmental Protection Agency

Office of Mobile Sources

February 1993
I. Forward

The Clean Air Act, as amended in 1990, mandates market-based

approaches in certain Federal programs and encourages the use of

such approaches at the Federal, State, and local levels, as well

as by individual sources, to facilitate the attainment of

required emission reduction milestones and goals of Title I of

the Clean Air Act Amendments. In response to the Act, the Agency

has proposed and issued rules and guidance that incorporate the

use of market-based measures in Federal program areas such as

acid rain reduction and clean fuel fleet vehicle purchases.

To facilitate the development of market-based programs that

go beyond such Federal programs, the Agency is developing

comprehensive rules and guidance for States and individual

sources to follow in designing and adopting market-based programs

in State Implementation Plans (SIP's). The pending Economic

Incentive Program (EIP) Rule draws upon the general principles

found in the 1986 Emission Trading Policy Statement (see 51 FR

43631 December 4, 1986), while providing a broad framework for

the development and use of a wide variety of market-based control

strategies. For States to take credit in their SIP's for

emission reductions based upon such strategies, reductions must

be quantifiable, enforceable, surplus to other Federal and State

requirements, permanent within the timeframe specified by the

program, and consistent with all other statutory and Federal

regulatory requirements. The proposed EIP Rule is applicable to

all types of sources, including stationary and mobile sources,

and defines general regulatory elements (e.g., program baseline,

auditing procedures, enforcement requirements) that should be

included in the design of market-based control strategies.

In addition to this broadly applicable general rule, the

Agency is also developing a more narrowly focused document

entitled, "Guidance on the Generation of Mobile Source Emission

Reduction Credits," specifically for the development of marketbased programs involving emission reduction credits generated

from mobile sources. Such mobile source emission reduction

credits (MERC's) can be generated from surplus emission

reductions over and above Federal mobile source program

requirements and can potentially be used to substitute for

stationary source emission reduction requirements. The general

guidance on the generation of MERC's mentioned above addresses

issues unique to emission reduction credits generated by mobile

sources, including the calculation of emissions baselines for

participating sources, the projection of future emissions levels,

and the time-averaging of emission reduction credits that vary

over time.

To exemplify how MERC's can be generated from a specific

category of mobile sources, the following guidance addresses

accelerated retirement of vehicles programs (also known as

scrappage programs), and illustrates how the purchase of

vehicles, and their removal from use, can generate emission
 See Transportation Control Measure Information Documents, Accelerated Retirement of Vehicles, U.S. EPA, Office of Mobile Sources, March 1992

credits. While market-based mobile source programs must be 

consistent with the EIP Rule and the Guidance on the Generation

of Mobile Source Emission Reduction Credits, EPA does not intend

to limit flexibility and innovation beyond the requirements found

in these documents.

The following guidance is intended to assist program

sponsors in the design of scrappage programs, not to limit

initiative, creativity, or flexibility in developing a program

which best meets the sponsors' needs within the limits of good

environmental policy. The examples that are used in this

guidance to illustrate a methodology for calculating benefits and

an administrative framework for such a program are not

exhaustive. EPA encourages potential sponsors to maximize the

cost-effectiveness of scrappage programs, for example, by

targeting them towards vehicles which have already been

identified as high emitters (see Section VIII-C) or by targeting

the retirement bounty at vehicles equipped with the very oldest

emission control technology (pre-1975 model year).

II. Introduction

The Clean Air Act Amendments of 1990 define "programs to

encourage the voluntary removal from use and the marketplace of

pre-1980 model year light duty vehicles and pre-1980 model light

duty trucks" as a transportation control measure in Section

108(f). A scrappage program as described in EPA's recent

information document1

, could be such a measure. Additionally,

scrappage programs offer a cost-effective alternative to more

expensive and difficult stationary source emission control

measures. A scrappage program has the potential to create

additional flexibility, for governments and industry alike, by

allowing the generation of emission reduction credits from

existing mobile sources that could be traded to stationary

sources.

The purpose of this document is to provide guidance to

States that are interested in developing criteria and procedures

for the implementation and administration of scrappage programs. 

It discusses scrappage programs and specifies a base methodology

for the calculation of MERCs from such programs. It also

discusses some areas of uncertainty that program variations may

amplify, and for which the Agency seeks additional information

for the purpose of developing future guidance.

The document is divided into nine sections. Section III

contains background information to provide the context from which

this guidance should be viewed. Section IV discusses

requirements that must be included in scrappage programs in order
for credits to be calculated from the methodology described in

this document. Section V provides the base methodology for the

calculation of MERCs, that if followed, would be readily

acceptable to EPA. Section VI provides an example illustrating

how to calculate MERCs using the base methodology. Section VII 

discusses some areas of uncertainty which may affect the emission

reductions that are actually achieved. Section VIII describes

program variations, which, if developed and addressed properly,

could increase emission reductions and improve costeffectiveness. Finally, Section IX defines the applicability of

generated emission credits.

This document is an addendum to EPA's general guidance

document, "Guidance on the Generation of Mobile Source Emission

Reduction Credits." The requirements, discussions and examples

are related only to the generation of emission reduction credits

from scrappage programs. Guidance related to the use of emission

reduction credits can be found in the general guidance document.

III. Background

Old automobiles with no or few emission controls are

typically a source of high emissions. Newer vehicles possessing

emission controls which have been tampered with, maintained

improperly, have failed, or have otherwise been rendered

ineffective are also significant contributors of emissions. 

While normal attrition of the fleet solves some of this emissions

problem, some high emitting vehicles remain in operation and

contribute to the problem for long periods of time. It is these

vehicles which scrappage programs seek to remove from the fleet

by providing an incentive for owners to retire these vehicles

sooner than they would have in the absence of the program.

A State or local government can design a scrappage program

as a SIP measure or, in conjunction with a private company, as a

program to generate emission credits to satisfy existing or new

source-specific requirements. Scrappage programs can be designed

as either emission-limiting or market-response programs. An

emission-limiting program would directly specify a level of

emission reduction to be achieved (e.g., scrap vehicles until the

desired reduction is achieved). In contrast, a market-response

program would create an incentive to reduce emissions without

directly stating a specific emission reduction target (e.g.,.set

a price for certain vehicles and scrap those that respond). The

proposed EIP rule provides guidance for both types of programs.

While the potential for variations such as those described

in Section VIII exist, programs will basically work in the

following way. A State or local government or company would

advertise for the purchase of certain vehicles. Owners would

then voluntarily sell their vehicles to the sponsor of the

program and the vehicles would be removed from the fleet. The
sponsor would receive an emission credit for each car removed

from operation equivalent to the difference between the emissions

from the retired vehicle and the emissions from the replacement

vehicle.

Although this guidance generally addresses light-duty 

vehicles, EPA recognizes that old light-duty trucks were also

built without emission control equipment, and that the

introduction of emission control components lagged behind those

for cars. EPA encourages States to consider the application of

this guidance to programs that include trucks.

As indicated above, scrappage programs must follow a number

of general requirements that are detailed within other guidance

and rules. The next section provides additional specific

guidance relevant to scrappage programs.

IV. Requirements for Scrappage Programs

In order to ensure that scrappage programs yield the

expected levels of emission reductions, minimum safeguards should

be provided in order to receive tradeable credit. EPA therefore

requires the following program design elements in scrappage

programs as a condition to using the methodology contained in

this document. If these elements are not present, EPA will

consider the program particulars on a case by case basis, due to

greater uncertainty of emission reduction claims.

 1. Twelve month registration requirement

To ensure that vehicles are not imported into the area for

the sole purpose of being sold in the program, eligible vehicles

must have been registered by the owner at an address within the

nonattainment area continuously for at least the previous twelve

months prior to the date the vehicle is purchased by the program.

 2. Vehicle must be operable and driven to site

Scrappage programs should seek to remove those high emitting

vehicles which would have been operated in future years and not

to attract vehicles which are inoperable or have little remaining

useful life. Eligible vehicles are required to be operable and

driven to the intake site to increase the probability that the

scrappage program will attract in-use vehicles. In addition,

they must undergo a physical inspection designed to assure that

major body components have not been removed and that the vehicle

could be readily used for normal transportation purposes.
 3. Owner must be present and possess a valid title

The owner of the vehicle or his or her legal representative,

or in the case of corporate owned vehicles, a certified agent,

must be present to ensure proper passage of title, and verify the 

owner's intention to retire the vehicle. Since these vehicles

will either be destroyed or dismantled for partial recycling,

they cannot be returned to the owner if a mistake is made. The

identification of the person delivering the vehicle, the Vehicle

Identification Number (VIN) and the validity of the vehicle title

must be verified.

 4. Owner must have a valid I/M certificate (where 

 applicable)

As a further assurance that the vehicle being retired is an

in-use vehicle, scrappage programs must require the owners to

present the I/M certificate (or waiver certificate if the car

received a waiver) obtained from the previously required testing

period (where I/M is applicable).

 5. Environmentally Safe Disposal

A scrappage program will generate solid, liquid, and gaseous

waste which must be disposed of or recycled in an environmentally

sound manner. EPA requires that all retired vehicles be scrapped

by facilities which are licensed and approved to dispose of all

the types of waste created by the scrappage of vehicles or

recycling of vehicle parts, where licensing requirements apply. 

In areas where such licensing requirements are not in place,

programs must adhere to all applicable Federal, State, and local

recordkeeping procedures and laws for disposal of vehicles. 

Where legal requirements are not in effect, all prudent

environmental safeguards should be strictly followed to ensure

that scrappage of vehicles does not result in environmental

degradation.

EPA is considering whether to issue supplemental guidelines

that States should follow to ensure that vehicles are disposed of

or parts are recycled in an environmentally sound manner. The

supplemental guidelines would include criteria for materials

disposition that disposal facilities should be required to meet

whether licensed or not. EPA is interested in receiving comments

regarding what criteria might be included in those guidelines. 

Anyone wishing to submit comments on the criteria should send

them in writing to: U.S. Environmental Protection Agency,

Transportation Section, 2565 Plymouth Road, Ann Arbor, MI 48105.

The overall environmental and economic impact should be

examined by program sponsors when considering the method of
 For California programs, the requirements of this section may be applied to the EMFAC model if currently accepted by EPA for use in SIP submittals.

 If exhaust and evaporative emissions tests other than the Federal Test Procedure (FTP) are used, proof of correlation to the FTP must be submitted and approved by the EPA. The I/M240 is one such acceptable

exhaust emissions test.

vehicle disposal to be used. For non-emissions related parts,

program sponsors may wish to make use of the broader

environmental benefits of the automotive dismantling and

recycling industry when economically feasible. The recycling of

a vehicle's major body components and other non-emissions related

parts could be allowed where proper safeguards are implemented to

assure that emissions related parts are effectively destroyed.

 6. Emission Estimates

The estimates used in the base methodology for calculating

MERCs, described in Section V, come from the latest MOBILE model

released by EPA2. The most recent version of the model must be

used for program evaluations begun three months or more after the

release of an updated model.

As an alternative to the MOBILE model's average emissions

approach, program sponsors may choose to use actual tested

emission levels as the basis for emission estimates. For the

purpose of quantifying those emission levels, a transient mass

exhaust emissions test, and if desired, an evaporative emissions

test procedure3

 should be used. If this approach is used, other

program design elements will be required to guard against the

possibility of tampering to increase emissions and the resulting

credits. This issue is discussed more fully in Sections VII and

VIII.

 7. Minimum data gathering requirements for programs 

over 2500 vehicles

Sponsors which retire more than 2500 vehicles within any

twelve month period are subject to a minimum data gathering

requirement. Sponsors must collect emissions data, using EPA's

I/M240 mass emission test and evaporative purge and pressure

tests, from a random sample of a statistically significant number

of participating vehicles. Sponsors must also collect

information on annual VMT, expected remaining useful life, and

model year of replacement vehicle. The information will be

provided to EPA for evaluation of program emission estimates and

for the purpose of improving future guidance on emission

reduction estimates for scrappage programs.
 Advance estimates may be desired in order to evaluate program cost-effectiveness or to predict emission reductions for a State Implementation Plan. EPA does not intend to issue tradeable credits based upon

predicted emission reductions from proposed future scrappage programs.

 8. State Responsibility

States allowing MERCs for retirement programs are

responsible for assuring that programs are implemented in

accordance with this guidance. Since these programs have the

potential to change fleet emissions characteristics, MERCs

claimed for these programs must be properly accounted for in

applicable State Implementation Plans. Baseline emissions

projections must be adjusted to assure that double counting of

the emission reductions has not occurred.

V. Base Methodology for Calculating MERCs

The base methodology, consisting of the eight basic steps

described below, is designed to ensure that emission reduction

credits can be reasonably determined without emission testing. 

The estimates of emission levels described in steps 5 and 6 are

based on local fleet and ambient characteristics entered into

EPA's MOBILE model. However, the use of emission tests, as

described in Sections VII and VIII, to establish vehicle emission

levels could be used as an alternative.

 1. Determine or estimate the number of vehicles to be

retired, by model year.

When the scrappage program has been executed, or partially

executed, the number of vehicles retired by model year can be

determined by simple counting. The following paragraphs address

a situation in which an advance estimate of credit is desired or

required4

.

A model year distribution for a scrappage program reflecting

the model year distribution of eligible vehicles in the local

area is required for accurate estimates of emission reductions. 

The first step is to estimate the model year distribution of

vehicles expected to participate in the program. Determining

this distribution requires information about the distribution of

the eligible fleet. The eligible fleet is defined as the subset

of model year vehicles from the area fleet that could potentially

participate. The most reliable source of this information is

actual vehicle registration data that can generally be obtained

from a State's Department of Motor Vehicles (DMV) or equivalent

agency.

The incentive offered to entice owners of old vehicles to

participate, relative to the market value of the various model

years and makes, will affect the actual distribution of
participating vehicles. Program sponsors must assure that

incentives are sufficient to attract a level of participation

that reflects the distribution estimates made in the analysis. 

If alternative incentives are offered, sponsors should modify the

model year distribution accordingly.

Determining the number and model year of vehicles which will

be retired depends on several factors, including the amount of

money or other incentive which will be offered for each retired

vehicle, the number of eligible vehicles that exist in the fleet,

the method of advertising, and the convenience of the scrappage

site to various groups of owners. Some insight on appropriate

incentives and number of vehicles may be gleaned from a used car

market value reference such as a "blue book," or a local

newspaper's classified advertisements, and State DMV statistics

 2. Estimate changes in fleet size

Determining the effect the program will have on the size of

the fleet is important because fleet size affects evaporative

emission totals, independent of vehicle miles traveled (VMT). 

Scrappage programs cause a portion of the fleet to be retired

from use faster than it would have been without a program. While

the drivers' need to travel may not have changed, vehicle

replacement is uncertain. Some vehicles will be replaced, some

of the owners may now choose to drive another car that they own

more than before, and some may utilize alternative modes of

transportation.

This methodology has made assumptions that total fleet VMT

will remain the same before and after the program and that the

VMT from the scrapped vehicles is redistributed to the remaining

fleet in proportion to the travel fractions that exist for the

entire fleet. These assumptions are discussed below in part (3)

of this section. These assumptions imply that there would

necessarily be fewer vehicles in the fleet, at least immediately

after the program. This can be conceptualized by thinking of

lower VMT vehicles being replaced by higher VMT vehicles, but

holding total VMT constant. The result is fewer total cars. 

With time, fleet size is likely to return to a "natural" level,

through increased new car purchases and slower retirement of

existing vehicles.

Fewer but higher VMT vehicles, on average, would have lower

diurnal evaporative emissions per mile of travel. Without

adjusting mileage accumulation rates in the MOBILE model, this

discrepancy cannot be addressed satisfactorily. The net effect

on emission calculations is minor, and the effect on fleet size

is likely to be only temporary. These considerations warrant

taking the more conservative and simplified approach of ignoring

the potential change in the total number of vehicles in the

fleet.
 U.S. Department of Energy, Fuel Purchasing Patterns and Vehicle Use Trends from the NPD Research Gasoline Diary Data Base: October 1983 - September 1984 Data Display, January 1988.

 3. Estimate changes in VMT

Two basic estimates need to be made: 1) What is the effect

on total VMT in the area when older vehicles are scrapped; and 2)

How are the VMT, which were attributed to the retired vehicles,

redistributed in the remaining fleet? Estimates of these changes

in VMT in the area as a result of the program are important

because VMT affects numerous critical internal calculations and

inputs to the MOBILE model. For instance, the MOBILE model

assigns the number of trips made by vehicles based upon VMT. The

number of trips is important within the MOBILE model since a

significant portion of a trip's emissions is generated when a

trip begins and the engine is cold.

It is reasonable to assume that scrappage programs will not

change total VMT significantly because people's transportation 

needs will not necessarily change. However, data suggest that

within the national fleet, newer vehicles travel farther than

older vehicles5

. Since the post-program fleet will be somewhat

newer, it could be argued that there may be slightly more VMT. 

EPA believes that for most programs, any increase in total area

VMT will be insignificant and that the methodology should assume

that total VMT remains the same before and after the program. In

effect, EPA is assuming that newer cars are used more because

drivers with larger VMT needs can afford and choose the greater

reliability, comfort, and fuel economy of newer cars. Their VMT

needs are, however, basically fixed. EPA believes that this is a

more reasonable assumption than an assumption that the driving

performance of a newer car unleashes some previously pent up

desire or need to travel.

Inherent in the determination of the change in VMT is the

estimation of the redistribution of VMT from the retired

vehicles. This estimation is difficult, and empirical data are

scarce. States should assume that the VMT of the retired

vehicles are absorbed by the remaining fleet in the same

proportion that exists for the total fleet in the MOBILE model. 

If, for example, ten percent of the total fleet VMT are assigned

to 1989 model year vehicles, then ten percent of the VMT of the

retired vehicles are assigned to 1989 model year vehicles in the

remaining fleet.

 4. Estimate the expected years of remaining life for the

retired vehicles.

The expected remaining useful life of any given group of

vehicles will vary by geographic location. Differing estimates

may be used if supported by accurate local or regional data on
 U.S. Department of Transportation, FHWA, Highway Statistics, 1991

 U.S. Department of Energy, Transportation Energy Data Book: Edition 11, Oak Ridge National Laboratory, January 1991.

remaining useful life, or by projections from related data

sources.

Regardless of geographic location, annual VMT and the number

of vehicles which "naturally" survive from any given starting

group of vehicles decrease each year. Therefore, a program which

scrapped typical vehicles from this fleet segment would earn the

most credit in the first few years and earn smaller amounts of

credit over time. A few vehicles in a group of scrapped vehicles

could, in the absence of a scrappage program, continue to operate

substantially longer than the average vehicle of that vintage. 

However, EPA anticipates that there is a possibility that the

vehicles attracted by a scrappage program will not be typical or

representative of the fleet. Instead, scrapped vehicles may be

mechanically worse than average and may have shorter useful lives

than others their age. Also, when some cars of a certain model

year are removed from service through a scrappage program, the

market value of the others in that age group will increase, which

will tend to reduce their "natural" scrappage rate.

However, EPA remains open to the possibility that an area

and program-specific remaining life assumption could be assumed

for any group of scrapped vehicles if supporting information or 

program design elements were present. EPA will consider

remaining life assumptions based upon such information including,

but not limited to, data gathered from previous program studies,

professional independent mechanical condition assessments, or

information on the correlation between vehicle procurement

incentives and the mechanical condition of participating

vehicles.

Where such regional or local data, or other supporting

program information or design elements are not present, three

years of remaining useful life, estimated by EPA from national

data on 1979 and earlier model year vehicles, should be used. 

EPA has evaluated the effect of age on useful life and remaining

VMT based on national fleet data from the 1984 National Purchase

Diary (adjusted to reflect FHWA 1990 total VMT estimates)6

 and

from the Transportation Energy Data Book7. Our analysis

indicates that if a vehicle were to travel at its age-specific

VMT accumulation rate for three years, then it would accumulate

all of the expected remaining VMT for an average vehicle of that

vintage. EPA believes that this three year limitation is a

reasonable policy choice on how long credit should be granted.

EPA analysis of the same data indicates that the 1979 and

earlier model year segment of the fleet has an average annual

retirement rate of about 20% (the average vehicle in this segment

has a 20% chance of being retired in a given year). Therefore,
within this three year window, the number of vehicles affected by

the accelerated retirement event must be reduced by 20% per year. 

Likewise, where local or regional remaining life estimates are

used, a comparable age-specific retirement rate derived from

local or regional scrappage/survival statistics must be used to

reduce the affected number of vehicles.

The calculation of a declining number of vehicles in the

scrapped fleet and the truncation of emission credit at three

years are policy choices to set a national default value for

these parameters in the example program described in this

guidance. These choices are made in light of the uncertainties

and the possibility of biased recruitment in scrappage programs

in cases where the data described above to support alternative

estimates are unavailable or unreliable. They are not meant to

establish precedents for remaining life estimates for scrappage

programs which use vehicle specific data to estimate remaining

useful life or other programs which might need such estimates in

order to calculate benefits.

 5. Estimate the average emission rate per year from the

retired vehicles.

Estimates of the average emissions from the retired vehicles

are calculated by the MOBILE model for each calender year, taking

into account local characteristics such as model year mix,

ambient temperature, fuel, average speeds, and any local control

program. The MOBILE model should be run with a zero value

entered for the registration distribution and mileage 

accumulation inputs for the non-retired model years. The average

grams per mile will be indicated at the bottom of the column

labeled FER on the MOBILE "By Model Year" output table.

 6. Estimate the average emission rate per year from the

replacement vehicles.

A determination of the emission characteristic of the

replacement vehicles for each calender year is also needed. 

Consistent with the assumption about the redistribution of

scrapped vehicle VMT, the replacement vehicle is assumed to be

the average vehicle in the entire fleet, including older vehicles

which were not scrapped. As in part (5), estimates of the

average emissions from the entire post-program fleet are based on

the local characteristics and are calculated by the MOBILE model. 

To estimate the average emissions of the replacement vehicles,

the MOBILE model should be run for all model years. The average

grams per mile will be indicated in the column labeled FER on the

MOBILE "By Model Year" output table. It is optional whether to

adjust age distribution at this step to account for the removal

of some vehicles, since the effect may be too small to appear in

the significant digits of the output.
 7. Calculate the average yearly emissions benefit for each

retired vehicle

The average yearly benefit of the program for each vehicle

retired from the fleet is the difference between the average

emission rate of the scrapped vehicles and the average emission

rate of the replacement vehicles, multiplied by the average

annual VMT of the scrapped vehicles. The average annual VMT of

scrapped vehicles is the average annual mileage accumulation

taken from the MOBILE model, for the model years of the vehicles

being scrapped. Model years can be treated individually, or

aggregated by the number of vehicles scrapped from each. This

annual VMT value will decrease in accordance with the MOBILE

model, for each successive year of the creditable three year

period.

 8. Calculate the total emission reduction in tons per year

removed by the program.

To calculate the tons removed by the program, multiply the

average yearly emissions benefit of each retired vehicle by the

number of vehicles retired by the program and convert to tons. 

This calculation is done for each of the three creditable years 

As mentioned in part (4) of this section, the methodology assumes

an annual "normal" retirement rate. The total number of vehicles

represented in years two and three reflect this reduction. Since

the MOBILE model reports emission levels in grams per mile per

vehicle, the values need to be converted to tons.

VI. Example

The example used to illustrate the methodology is

hypothetical and does not represent an Agency position on

appropriate program size or design. The values used in the

calculations are based upon data representing national fleet

averages and may not be representative of any particular urban

area.

Table 1 provides an estimate of the emission reductions that

could be realized from a program operating in 1993, in which

10,000 pre-1980 model vehicles are retired.
Table 1.

Program to Retire 10,000 Vehicles in 1993

Year Emission Reduction (tons)

VOC NOx CO

1993 343 115 2600

1994 272 91 2085

1995 216 72 1657

Total 831 278 6342

Avg/Yr 277 93 2114

All of the emission estimates were made using the mobile

source emissions model, MOBILE4.1. Baseline and post-program

scenarios use national average default values to describe the

vehicle fleet, standard speeds, and typical summer temperatures. 

The scenarios assume a low altitude area with an ASTM class "C"

fuel. The area is also assumed to have an existing "basic"

Inspection/Maintenance program with an idle test covering all

model years of vehicles.

A step by step description of the base methodology and how

it was applied to the example follows and is shown in Table 2.

 1. Estimate the model years and number of vehicles to be

retired.

For this example, the model year distribution of the

participating vehicles is assumed to be identical to that of the

eligible fleet and is based upon national fleet model year

distribution from the MOBILE4.1 model. It is assumed that 10,000

pre-1980 model year vehicles are scrapped on January 1, 1993.

 2. Estimate changes in fleet size.

For this example, it is assumed the total number of vehicles
in the fleet remains the same as before the program was

implemented.

 3. Estimate changes in VMT.

EPA's approach keeps total VMT the same before and after the

program. The values are determined by the annual mileage

accumulation in the MOBILE model and are supported by data

reported by Oak Ridge National Laboratory in the Transportation

Energy Data Book: Edition 11, and also by data collected by

UNOCAL during the demonstration program in Los Angeles during the

summer of 1990. The average VMT per year per retired vehicle is

5182 miles in year 1, 4920 miles in year 2, and 4680 miles in

year 3.

 4. Estimate the expected number of years of use remaining for

the retired vehicles.

The expected number of years of use remaining in the retired

vehicles is three years.

 5. Estimate the average emissions per year from the retired

vehicles.

The average emissions from the retired vehicle were

estimated by EPA's mobile source emissions model, MOBILE4.1,

using national average characteristics for climate, geography,

local control program, and vehicle fleet (altitude, fuel, I/M

program, fleet, travel fraction, etc.). The MOBILE model was

then run for three successive years, 1993, 1994, 1995. The

average emissions were determined by running the model with zero

registrations and zero mileage accumulation for 1980 and newer

model years. The average grams per mile are indicated at the 

bottom of the column labeled FER on the MOBILE4.1 output

table(See attachments 1, 2 and 3).

The emission levels for the retired vehicles in each of the

three years were as follows: 8.87 g/mile in 1993, 9.06 g/mile in

1994, and 9.26 g/mile in 1995.

 6. Estimate the average emissions per year from the replacement

vehicles.

The estimates of the average emissions from the entire postprogram fleet were based on the same national average

characteristics mentioned in step (5). To estimate the average

emissions of the replacement vehicles the MOBILE model should be

run for all model years for 1993, 1994 and 1995. The average

grams per mile will be indicated in the column labeled FER on the

MOBILE4.1 output table(see attachments 4,5 and 6).

The emission levels for the replacement vehicles in each of
the three years were as follows: 2.20 g/mile in 1993, 2.09 g/mile

in 1994, and 2.00 g/mile in 1995.

 7. Calculate the average yearly emissions benefit for each

retired vehicle.

Subtract the result of step 6 from the result of step 5 and

multiply by the average VMT per scrapped vehicle, determined in

step 3, for each calender year. The results are 34564

grams/vehicle in 1993, 34292 grams/vehicle in 1994, and 33977

grams/vehicle in 1995.

 8. Calculate the total emission reduction in tons per year

removed by the program

Multiply the average emissions benefit for each retired

vehicle by the effective number of vehicles retired, and

convert to tons for each calender year. To determine the

effective number of vehicles for each year, reduce the

number of scrapped vehicles by the "normal" retirement rate. 

For this example, the national rate of decline of 20% per

year will be assumed, starting immediately after the

scrappage event. Averaged over each of the three years, the

effective number of vehicles for each year is 9000, 7200,

and 5760 respectively.
 Recent work, related to the Environmental Defense Fund/General Motors scrappage proposal described later in this document, provides information on VMT and remaining life, aggregated by regions of the U.S.

Table 2.

Hydrocarbon Emission Reduction

Example: 10,000 pre-1980 model year vehicles scrapped on 1/1/93

1993 1994 1995

HC/retired vehicle (g/mile) 8.87 9.06 9.26

HC/replacement vehicle (g/mile) - 2.20 2.09 2.00

HC reduction/vehicle (g/mile) = 6.67 6.97 7.26

VMT/year/retired vehicle x 5182 4920 4680

Grams/vehicle/year = 34564 34292 33977

Effective number of vehicles* x 9000 7200 5760

Conversion (grams to tons) x .000001102 # # 

Tons per year = 343 272 216

(*) The analysis assumes that all of the retired vehicles would

have been scrapped within 3 years. This method assumes a 20%

scrappage rate per year for three years, and provides for no

reduction credit beyond the three year remaining life assumption.

VII. Areas of Uncertainty

Because there is a good correlation between the age of the

vehicle and the level of emissions, the base methodology will be

sufficient for estimating emission reductions from age-based

programs. The base methodology was developed from empirical data

and from careful consideration of areas of uncertainty. EPA

recognizes that future scrappage programs offer the opportunity

to gather better data and has set minimum data gathering

requirements for sponsors that retire more than 2,500 vehicles

within a twelve month period (see Section III-7). EPA encourages

all program sponsors, regardless of size, to address the areas of

uncertainty outlined below in their program designs and to gather

data which can be used to update future guidance8. For now, EPA

will consider alternatives to the assumptions for base

methodology where there are sufficient supporting data and
information.

 1. Tailpipe and evaporative emissions

Testing a vehicle's actual tailpipe emissions using a

transient mass emissions test procedure may provide more accurate

emissions reduction estimates, but if used to screen out clean

cars or to quantify the credit for specific cars, it may also be

an incentive to tamper with the vehicle to increase its emissions

and credit value. EPA encourages the testing of participating

vehicles to gather information on their actual emissions, but the

test results should enter into a calculation of credits only if

the vehicle owner and the scrappage sponsor are kept ignorant of

the results, or if an EDF/GM-type approach to measurement pooling

(see Below) is used. Simpler idle-type tests should not be used

as a screen.

Evaporative emissions cannot practically be measured in a

scrappage program, but physical inspection using pressure and

purge tests is possible and allows a rough estimate of

evaporative emission levels. Similar considerations apply as for

tailpipe emissions.

Vehicles which are due for testing as part of a State I/M

program raise additional concerns. If the vehicle is in a test

failing condition at the time it enters a scrappage program,

exhaust and evaporative emissions tests may yield emission

estimates that are unrepresentative of that vehicle for future

years, since required I/M repairs would likely reduce its

emissions. Conversely, a vehicle with relatively low emissions

at the time of scrappage, could have suffered a malfunction and

produced higher emissions in the future. Section VIII-C

discusses an appropriate approach for adjusting tested emission

levels in areas that have I/M programs in operation. However,

States may choose to allow only age-based average emission

estimates for vehicles which are shortly due for their I/M test.

 2. VMT Determination

The VMT of both the scrapped and replacement vehicles is

critical to the calculation of the MERC, but due to the lack of

available data, the base methodology uses age-based averages. 

EPA believes that, where actual data are unavailable, an estimate

based on the MOBILE model is appropriate. EPA encourages data

gathering to help clarify the actual annual VMT of scrapped

vehicles and replacement vehicles. The Agency understands of

course, that the data will be indirect in nature since, once

scrapped, it is impossible to tell how any specific vehicle would

have been kept and used.
 Fairbank,. Bregman and Maullin, "Final Summary Report of the Results of the Unocal SCRAP Program Post-Participation Survey," January, 1991

 3. Replacement Vehicle Determination

How the VMT of a scrapped vehicles is redistributed to the

model years in the remaining fleet is necessary to calculate

emission reductions. However, it is very difficult to predetermine what type of vehicle, if any, will be used to replace

the scrapped vehicle. The assumption made by EPA in the base

methodology is derived from the data gathered from the Unocal

study9

. EPA encourages the sponsors of scrappage programs to

gather information on the redistribution of VMT from scrapped

vehicles. However, in light of the complexities of frequent and

ongoing vehicle transfers, it will be difficult to be sure what

vehicle(s) has actually been the supplier of replacement VMT.

 4. Remaining life of scrapped vehicles

EPA limits the length of time emission reductions are 

creditable, based, in part, upon expected VMT within the

remaining life of the average scrapped vehicle (see Section V.).

The actual remaining life of participating vehicles may be

influenced by program design. For instance, programs may attract

a disproportionate number of vehicles which would have been

retired soon on their own anyway. Programs offering very low

incentives for vehicles would encourage the retirement of

vehicles with little remaining life. While EPA will not require

programs to offer a minimum incentive per vehicle, EPA encourages

program sponsors to offer incentives that will attract a true

cross section of vehicles within each age group, rather than just

those with low market value or remaining useful life. Likewise,

if people are aware that a scrappage program will be regularly

repeated, there may be an incentive for them to hold on to their

older vehicles longer since they can sell them to the program

instead of selling or retiring them when they otherwise would

have done. EPA encourages the gathering of data on the expected

remaining life of participating vehicles and its relationship to

the value of incentives or other program design elements.

VIII. Program Variations

Basic scrappage programs can be varied by changing the focus

of vehicle selection from general model year eligibility to

emissions level eligibility. EPA encourages scrappage programs

to focus on high emitters and recognizes that there are many

possible program variations that could assist in that regard. 

Some may require alternative assumptions or other modifications

to the basic methodology for the calculation of emission

reductions.
 A copy of the EDF/GM white paper detailing the program is available from EDF. Those interested in obtaining a copy should contact EDF at their Washington, D.C. office.

Program sponsors should give careful consideration to the

effect that variations may have on effectiveness. Program

variations require careful design and implementation in order to

prevent fraud and misuse, and to decrease the effects of

uncertainty. Some examples of possible variation are described

below. These variations should be viewed only as points for

discussion and should not substitute for local selection of

program variations.

A. EDF/GM Test and Pool Approach

A scrappage program design proposal from the Environmental

Defense Fund (EDF) and General Motors Corporation (GM) addresses

some of the areas of uncertainty and is conducive to

establishment of an ongoing program10. The EDF/GM design targets

high-emitting vehicles regardless of age, awards emission

reduction credits on the basis of emissions testing for each

scrapped vehicle and creates an emissions reduction "pool" for

the purpose of nullifying the incentive to tamper with individual

vehicles. Under the program, vehicles are purchased for a

negotiated amount reflecting the local market price for emission

reduction credits in the area and generic information about the

emissions and expected remaining life of the specific vehicle

model and vintage. Presumably, in an active, ongoing program,

private parties would accumulate and circulate such information,

just as the retail market for used cars has created a "Blue

Book," recording generic information about the transportation

value of vehicles. Following purchase, the buyer would present

the vehicle to an independent testing center where the emissions

would be measured. The emission results, factored by projected

annual VMT and remaining life, would be included in pools of the

emission results of all cars purchased by scrappage sponsors in

the area. Emission values would be reduced to reflect the

emissions from replacement vehicles. Such pools would be created

for each year of expected remaining life.

As an added assurance that the program provides net emission

reductions, each year's emissions pool would be discounted by

10%. The remainder of the annualized emissions pool would be

distributed in the form of transferable MERCs, to each scrappage

sponsor on a pro-rata basis reflecting the sponsor's share of all

scrapped vehicles whose emissions were included in the pool.

To bolster the pooling approach for minimizing the incentive

for sponsors to tamper with vehicles to increase their emissions,

local regulatory authorities would adopt an oversight procedure. 

By selling a "control" vehicle with known emissions to a

scrappage sponsor and obtaining the emission test results from

the independent test facility, tampering could be detected. 

Stiff penalties for tampering, including disqualifying the
sponsor from future scrappage programs and disallowing MERCs

already generated by the sponsor would nullify the incentive to

tamper, while also ensuring that any tampering already committed

would not have an adverse effect on air quality.

B. Scrappage and Remote Sensing

Programs that use a remote sensing device (RSD) to target

vehicles for participation in a scrappage program may reduce some

of the uncertainty found in programs with eligibility based only

on age and improve cost-effectiveness. Specifically, RSD may

increase program cost-effectiveness by identifying older cars

that are higher emitters than the average car of their age, and

it may reduce credit overestimation by identifying vehicles which

are actually in active service and not just being stored or used

very infrequently. Scrapping only vehicles identified by on-road

remote sensing should, therefore, produce more emission

reductions per scrapped vehicle. EPA encourages consideration of

this approach. However, if the emission estimates used for

calculating the MERCs are to be increased over those predicted by

the MOBILE model, transient mass emissions testing is required to

determine how much larger the increases should be. Special

program design elements should also be included to guard against

intentional tampering for the purpose of increasing emissions and

the resulting credits. An EDF/GM-type measuring approach is one

solution. Interested parties should contact EPA to discuss any

other ideas they may have.

C. Scrappage and I/M Programs

Adding a vehicle scrappage option to an I/M program is

another way to improve program benefit and/or reduce costs. I/M

programs require vehicles to pass an emissions test in order to

be registered or licensed for operation. If a vehicle does not

pass the test, owners are required to make repairs up to a

certain dollar amount. If, after making the repairs, the vehicle

still cannot pass the test, the owner may receive a waiver which

allows the vehicle to be licensed for use until the next

scheduled test.

Vehicles that fail an I/M test, and which have not yet been

successfully repaired, or are known to need repairs costing

greater than a predetermined amount, would become eligible for a

scrappage program. Depending upon the estimated cost of repair,

emission reduction credits would be based upon either the

vehicles' emission levels from an I/M240 test, or emission

estimates from the MOBILE model.

For example, vehicles requiring less than $300 in repairs

would be assigned the MOBILE estimate of emission levels for the

appropriate model year. Vehicles requiring $300-$450 in repairs

would be assigned an emission level that is less than the initial
 TECH5 is an EPA model that is used to predict the effect that I/M programs have on emission levels of passenger vehicles. A description of the Tech5 model can be found in the Technical Support Document for

the I/M rule, "I/M Costs, Benefits, and Impacts", November 1992.

I/M240 test results, to reflect the repairs and the post-repair

emission levels it would likely have reached in absence of the

scrappage option. This post-repair emission level is derived

from the TECH511 relationship between initial test emission

levels and post-repair test emission levels. Vehicles requiring

in excess of $450 would be assigned emission levels based upon

their initial I/M transient test. It should be noted that

serviceability and repair costs are difficult to predict without

professional diagnosis. Furthermore, a conflict of interest

could occur if the diagnosis were performed by someone whose

judgment may be influenced by the sponsor of the scrappage

program. Therefore, it is reasonable to require proof of an

independent professional diagnosis that supports the cost

estimate.

Scrappage program designs that incorporate an I/M element in 

this way will not only have greater assurance that they are

retiring high emitting vehicles, but could possibly offer lower

incentives since the vehicle owner is faced with immediate repair

costs if the vehicle is not scrapped. EPA encourages this

approach as a way to increase assurance of an environmental

benefit, as a way of lowering incentives, and as an

environmentally sound option to issuing a waiver to a high

emitting vehicle. As with the EDF/GM approach and the remote

sensing approach described above, special program features to

guard against cheating or fraud would be required.

IX. Applicability of Credits

A program can be designed to produce emission reductions for

a short-term or long-term period. A program could be conceived,

which operates continuously or intermittently over the course of

the attainment period, to produce essentially permanent emission

reductions. Retired vehicles are assumed to have a finite

remaining life that takes into account normal fleet turnover. 

Emission reduction credits will be applicable for future years in

which the vehicle would have been in operation in absence of the

program. In the example program, the retired vehicles are

assumed to have a maximum remaining life expectancy of three

years. Therefore, credit for the emission reductions are

applicable for only three years. If a program sponsor desires

emission reduction credits for use in additional future years,

the retirement program will need to operate in additional future

years and scrap more vehicles.

Any long-term or repeated scrappage program proposal raises

issues concerning when a tradeable credit is actually created and

granted, and how follow-through on the scrappage plan can be
ensured if the credit is granted and used by another source

before the scrappage event on which it is based is completed. In

general, credit generation and trading should not result in a

shift in enforcement liability to a party against which

enforcement is more difficult. Readers should refer to the

general guidance, to which this document is an addendum, for

guidance on these issues.
1BTEST2.INP : Basic I/M (only 1969-1979 model years) 

 ................- Light Duty Gas Vehicles  Jan 1, 19930Model | HC | CO |  Year TF Miles | BEF4 Tamper SALHCF Evapor Refuel Runnin Restin FER | BEF4 Tamper SALHCF FER | BEF4 +____ _____ _______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ _____ 1993 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1992 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1991 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1990 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1989 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1988 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1987 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1986 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1985 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1984 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1983 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1982 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1981 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1980 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1979 .2372 129594. 3.738 0.936 0.980 1.087 0.255 0.861 0.236 1.665 47.105 12.022 0.980 13.747 2.32 1978 .1798 135705. 3.809 1.039 0.980 1.127 0.259 0.861 0.249 1.303 48.090 13.103 0.980 10.784 2.37 1977 .1258 141485. 3.874 1.083 0.980 2.513 0.280 0.861 0.264 1.104 49.226 13.867 0.980 7.781 2.41 1976 .1278 146952. 3.927 1.201 0.984 2.582 0.294 0.861 0.279 1.158 50.094 15.810 0.986 8.306 2.68 1975 .0887 152125. 3.981 1.239 0.984 2.652 0.325 0.861 0.295 0.823 51.051 16.947 0.986 5.951 2.69 1974 .0610 157017. 4.783 0.184 0.981 2.725 0.359 0.861 0.312 0.557 49.747 5.217 0.981 3.287 2.87 1973 .0433 161645. 5.443 0.187 0.981 2.804 0.359 0.867 0.329 0.428 60.301 5.316 0.981 2.787 2.89 1972 .0341 166023. 5.527 0.063 0.986 2.884 0.353 0.872 0.348 0.340 62.996 1.803 0.982 2.173 3.87 1971 .0259 170164. 8.206 0.030 0.986 4.515 0.356 1.668 0.368 0.389 71.720 0.899 0.980 1.841 3.87 1970 .0184 174081. 8.391 0.031 0.987 3.872 0.344 1.668 0.389 0.268 74.914 0.913 0.979 1.364 3.87 1969 .0579 177787. 8.201 0.000 0.985 3.968 0.344 1.668 0.411 0.838 66.107 0.000 0.979 3.750 3.87+ ______ ______ ______ ______ ______ ______  2.146 0.294 0.944 0.281 8.873 61.771 
1BTEST3.INP : Basic I/M (only 1970-1979 model years) 

 ................- Light Duty Gas Vehicles  Jan 1, 19940Model | HC | CO |  Year TF Miles | BEF4 Tamper SALHCF Evapor Refuel Runnin Restin FER | BEF4 Tamper SALHCF FER | BEF4 +____ _____ _______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ _____ 1994 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1993 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1992 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1991 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1990 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1989 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1988 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1987 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1986 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1985 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1984 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1983 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1982 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1981 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1980 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1979 .2338 135705. 3.797 0.938 0.980 1.127 0.255 0.861 0.249 1.668 47.668 12.050 0.980 13.684 2.37 1978 .1650 141485. 3.855 1.039 0.980 1.169 0.259 0.861 0.264 1.212 48.443 13.103 0.980 9.950 2.41 1977 .1679 146952. 3.920 1.083 0.980 2.582 0.280 0.861 0.279 1.495 49.558 13.867 0.980 10.435 2.46 1976 .1167 152125. 3.962 1.201 0.984 2.652 0.294 0.861 0.295 1.071 50.411 15.810 0.986 7.621 2.69 1975 .0804 157017. 4.007 1.239 0.984 2.725 0.325 0.861 0.312 0.754 51.275 16.947 0.986 5.407 2.71 1974 .0570 161645. 5.443 0.184 0.981 2.800 0.359 0.861 0.329 0.562 60.819 5.217 0.981 3.688 2.89 1973 .0449 166023. 5.533 0.187 0.981 2.880 0.359 0.867 0.348 0.452 63.206 5.316 0.981 3.020 2.90 1972 .0340 170164. 5.626 0.063 0.986 2.963 0.353 0.872 0.368 0.346 64.950 1.803 0.982 2.230 3.87 1971 .0242 174081. 8.391 0.030 0.986 4.665 0.356 1.668 0.389 0.372 75.033 0.899 0.980 1.798 3.87 1970 .0762 177787. 8.571 0.000 0.987 3.968 0.344 1.668 0.411 1.132 77.024 0.000 0.979 5.751 3.87+ ______ ______ ______ ______ ______ ______  2.223 0.293 0.943 0.296 9.064 63.584 
1BTEST4.INP : Basic I/M (only 1971-1979 model years) 

 ................- Light Duty Gas Vehicles  Jan 1, 19950Model | HC | CO |  Year TF Miles | BEF4 Tamper SALHCF Evapor Refuel Runnin Restin FER | BEF4 Tamper SALHCF FER | BEF4 +____ _____ _______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ _____ 1995 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1994 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1993 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1992 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1991 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1990 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1989 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1988 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1987 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1986 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1985 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1984 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1983 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1982 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1981 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1980 .0000 0. 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.00 1979 .2136 141485. 3.842 0.938 0.980 1.169 0.255 0.861 0.264 1.545 48.095 12.050 0.980 12.588 2.41 1978 .2191 146952. 3.894 1.039 0.980 1.212 0.259 0.861 0.279 1.631 48.843 13.103 0.980 13.302 2.46 1977 .1526 152125. 3.955 1.083 0.980 2.652 0.280 0.861 0.295 1.377 49.862 13.867 0.980 9.531 2.50 1976 .1052 157017. 3.987 1.201 0.984 2.725 0.294 0.861 0.312 0.978 50.620 15.810 0.986 6.892 2.71 1975 .0747 161645. 5.080 1.239 0.984 2.799 0.325 0.861 0.329 0.787 64.580 16.947 0.986 6.007 2.73 1974 .0588 166023. 5.533 0.184 0.981 2.875 0.359 0.861 0.348 0.591 63.731 5.217 0.981 3.978 2.90 1973 .0446 170164. 5.632 0.187 0.981 2.958 0.359 0.867 0.368 0.457 65.269 5.316 0.981 3.085 2.92 1972 .0316 174081. 5.723 0.063 0.986 3.043 0.353 0.872 0.389 0.328 68.072 1.803 0.982 2.170 3.87 1971 .0998 177787. 8.571 0.000 0.986 4.754 0.356 1.668 0.411 1.561 77.265 0.000 0.980 7.559 3.87+ ______ ______ ______ ______ ______ ______  2.287 0.293 0.942 0.310 9.255 65.112 
1BTEST1.INP : Basic I/M (all model years) 

 ................- Light Duty Gas Vehicles  Jan 1, 19930Model | HC | CO |  Year TF Miles | BEF4 Tamper SALHCF Evapor Refuel Runnin Restin FER | BEF4 Tamper SALHCF FER | BEF4 +____ _____ _______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ _____ 1993 .0237 1640. 0.235 0.001 0.975 0.162 0.189 0.312 0.076 0.023 2.850 0.009 0.971 0.066 0.50 1992 .1133 9816. 0.269 0.005 0.975 0.162 0.189 0.312 0.077 0.114 3.408 0.038 0.971 0.379 0.52 1991 .1126 22403. 0.304 0.011 0.975 0.170 0.189 0.312 0.089 0.120 3.964 0.079 0.971 0.442 0.55 1990 .1053 34309. 0.337 0.015 0.975 0.204 0.186 0.336 0.092 0.122 4.521 0.109 0.971 0.474 0.58 1989 .1021 45572. 0.381 0.019 0.975 0.248 0.184 0.349 0.099 0.130 5.361 0.133 0.972 0.545 0.61 1988 .0931 56225. 0.438 0.023 0.975 0.289 0.181 0.388 0.113 0.132 6.420 0.155 0.971 0.595 0.64 1987 .0835 66303. 0.496 0.027 0.976 0.358 0.183 0.432 0.122 0.134 7.350 0.174 0.972 0.610 0.70 1986 .0574 75837. 0.535 0.031 0.981 0.436 0.185 0.476 0.149 0.103 7.861 0.209 0.976 0.452 0.75 1985 .0482 84854. 0.583 0.036 0.981 0.572 0.191 0.575 0.160 0.102 8.567 0.262 0.977 0.416 1.02 1984 .0461 93384. 0.658 0.039 0.977 0.688 0.196 0.672 0.177 0.111 10.147 0.279 0.975 0.469 1.12 1983 .0426 101452. 0.672 0.146 0.976 0.844 0.199 0.769 0.184 0.119 10.146 1.684 0.974 0.491 1.16 1982 .0424 109084. 1.049 0.200 0.977 1.023 0.199 0.848 0.195 0.148 16.817 2.395 0.976 0.795 1.44 1981 .0345 116304. 1.149 0.208 0.977 1.073 0.207 0.861 0.211 0.127 18.576 2.663 0.976 0.714 1.46 1980 .0261 123133. 0.960 0.725 0.977 1.047 0.221 0.861 0.223 0.104 9.331 9.131 0.976 0.470 2.39 1979 .0164 129594. 3.738 0.936 0.980 1.087 0.255 0.861 0.236 0.115 47.105 12.022 0.980 0.949 2.32 1978 .0124 135705. 3.809 1.039 0.980 1.127 0.259 0.861 0.249 0.090 48.090 13.103 0.980 0.744 2.37 1977 .0087 141485. 3.874 1.083 0.980 2.513 0.280 0.861 0.264 0.076 49.226 13.867 0.980 0.537 2.41 1976 .0088 146952. 3.927 1.201 0.984 2.582 0.294 0.861 0.279 0.080 50.094 15.810 0.986 0.573 2.68 1975 .0061 152125. 3.981 1.239 0.984 2.652 0.325 0.861 0.295 0.057 51.051 16.947 0.986 0.411 2.69 1974 .0042 157017. 4.783 0.184 0.981 2.725 0.359 0.861 0.312 0.038 49.747 5.217 0.981 0.227 2.87 1973 .0030 161645. 5.443 0.187 0.981 2.804 0.359 0.867 0.329 0.030 60.301 5.316 0.981 0.192 2.89 1972 .0024 166023. 5.527 0.063 0.986 2.884 0.353 0.872 0.348 0.024 62.996 1.803 0.982 0.150 3.87 1971 .0018 170164. 8.206 0.030 0.986 4.515 0.356 1.668 0.368 0.027 71.720 0.899 0.980 0.127 3.87 1970 .0013 174081. 8.391 0.031 0.987 3.872 0.344 1.668 0.389 0.018 74.914 0.913 0.979 0.094 3.87 1969 .0040 177787. 8.201 0.000 0.985 3.968 0.344 1.668 0.411 0.058 66.107 0.000 0.979 0.259 3.87+ ______ ______ ______ ______ ______ ______  0.521 0.197 0.493 0.134 2.202 11.183 
1BTEST1.INP : Basic I/M (all model years) 

 ................- Light Duty Gas Vehicles  Jan 1, 19940Model | HC | CO |  Year TF Miles | BEF4 Tamper SALHCF Evapor Refuel Runnin Restin FER | BEF4 Tamper SALHCF FER | BEF4 +____ _____ _______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ _____ 1994 .0237 1640. 0.235 0.001 0.975 0.162 0.189 0.312 0.076 0.023 2.850 0.009 0.971 0.066 0.50 1993 .1131 9816. 0.269 0.005 0.975 0.162 0.189 0.312 0.077 0.114 3.408 0.038 0.971 0.379 0.52 1992 .1124 22403. 0.303 0.011 0.975 0.171 0.189 0.312 0.081 0.119 3.935 0.079 0.971 0.438 0.55 1991 .1051 34309. 0.336 0.015 0.975 0.200 0.189 0.336 0.094 0.122 4.467 0.109 0.971 0.467 0.58 1990 .1019 45572. 0.369 0.019 0.975 0.224 0.186 0.349 0.098 0.126 5.014 0.133 0.971 0.509 0.60 1989 .0930 56225. 0.426 0.023 0.975 0.290 0.184 0.388 0.104 0.131 6.010 0.155 0.972 0.557 0.65 1988 .0836 66303. 0.488 0.027 0.975 0.330 0.181 0.432 0.119 0.131 7.137 0.174 0.971 0.594 0.67 1987 .0573 75837. 0.546 0.030 0.976 0.431 0.183 0.476 0.129 0.102 8.097 0.192 0.972 0.462 0.74 1986 .0484 84854. 0.581 0.034 0.981 0.547 0.185 0.575 0.158 0.100 8.537 0.226 0.976 0.414 0.79 1985 .0464 93384. 0.626 0.039 0.981 0.666 0.191 0.672 0.170 0.109 9.200 0.279 0.977 0.430 1.06 1984 .0427 101452. 0.702 0.042 0.977 0.826 0.196 0.769 0.187 0.116 10.834 0.296 0.975 0.464 1.16 1983 .0435 109084. 0.709 0.159 0.976 1.010 0.199 0.848 0.195 0.135 10.709 1.861 0.974 0.532 1.20 1982 .0348 116304. 1.099 0.214 0.977 1.065 0.199 0.861 0.206 0.126 17.634 2.596 0.976 0.688 1.49 1981 .0256 123133. 1.199 0.223 0.977 1.109 0.207 0.861 0.223 0.097 19.402 2.878 0.976 0.557 1.50 1980 .0160 129594. 0.979 0.751 0.977 1.087 0.221 0.861 0.236 0.065 9.423 9.569 0.976 0.296 2.44 1979 .0122 135705. 3.797 0.938 0.980 1.127 0.255 0.861 0.249 0.087 47.668 12.050 0.980 0.717 2.37 1978 .0086 141485. 3.855 1.039 0.980 1.169 0.259 0.861 0.264 0.063 48.443 13.103 0.980 0.521 2.41 1977 .0088 146952. 3.920 1.083 0.980 2.582 0.280 0.861 0.279 0.078 49.558 13.867 0.980 0.546 2.46 1976 .0061 152125. 3.962 1.201 0.984 2.652 0.294 0.861 0.295 0.056 50.411 15.810 0.986 0.399 2.69 1975 .0042 157017. 4.007 1.239 0.984 2.725 0.325 0.861 0.312 0.039 51.275 16.947 0.986 0.283 2.71 1974 .0030 161645. 5.443 0.184 0.981 2.800 0.359 0.861 0.329 0.029 60.819 5.217 0.981 0.193 2.89 1973 .0024 166023. 5.533 0.187 0.981 2.880 0.359 0.867 0.348 0.024 63.206 5.316 0.981 0.158 2.90 1972 .0018 170164. 5.626 0.063 0.986 2.963 0.353 0.872 0.368 0.018 64.950 1.803 0.982 0.117 3.87 1971 .0013 174081. 8.391 0.030 0.986 4.665 0.356 1.668 0.389 0.019 75.033 0.899 0.980 0.094 3.87 1970 .0040 177787. 8.571 0.000 0.987 3.968 0.344 1.668 0.411 0.059 77.024 0.000 0.979 0.301 3.87+ ______ ______ ______ ______ ______ ______  0.500 0.195 0.492 0.131 2.090 10.182 
1BTEST1.INP : Basic I/M (all model years) 

 ................- Light Duty Gas Vehicles  Jan 1, 19950Model | HC | CO |  Year TF Miles | BEF4 Tamper SALHCF Evapor Refuel Runnin Restin FER | BEF4 Tamper SALHCF FER | BEF4 +____ _____ _______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ _____ 1995 .0237 1640. 0.235 0.001 0.975 0.162 0.189 0.312 0.076 0.023 2.850 0.009 0.971 0.066 0.50 1994 .1130 9816. 0.269 0.005 0.975 0.162 0.189 0.312 0.077 0.114 3.408 0.038 0.971 0.378 0.52 1993 .1123 22403. 0.303 0.011 0.975 0.171 0.189 0.312 0.081 0.119 3.935 0.079 0.971 0.438 0.55 1992 .1049 34309. 0.334 0.015 0.975 0.202 0.189 0.336 0.086 0.121 4.422 0.109 0.971 0.462 0.58 1991 .1017 45572. 0.367 0.019 0.975 0.219 0.189 0.349 0.100 0.125 4.940 0.133 0.971 0.501 0.60 1990 .0928 56225. 0.411 0.023 0.975 0.267 0.186 0.388 0.103 0.127 5.578 0.155 0.971 0.517 0.63 1989 .0835 66303. 0.473 0.027 0.975 0.331 0.184 0.432 0.110 0.129 6.654 0.174 0.972 0.554 0.68 1988 .0574 75837. 0.538 0.030 0.975 0.403 0.181 0.476 0.126 0.100 7.859 0.192 0.971 0.449 0.70 1987 .0484 84854. 0.594 0.034 0.976 0.543 0.183 0.575 0.137 0.099 8.810 0.209 0.972 0.424 0.78 1986 .0467 93384. 0.625 0.037 0.981 0.643 0.185 0.672 0.167 0.108 9.179 0.243 0.976 0.429 0.82 1985 .0430 101452. 0.666 0.042 0.981 0.806 0.191 0.769 0.179 0.114 9.793 0.296 0.977 0.424 1.09 1984 .0436 109084. 0.743 0.045 0.977 0.994 0.196 0.848 0.197 0.131 11.486 0.313 0.975 0.501 1.20 1983 .0357 116304. 0.745 0.172 0.976 1.053 0.199 0.861 0.206 0.115 11.245 2.039 0.974 0.462 1.24 1982 .0259 123133. 1.147 0.226 0.977 1.101 0.199 0.861 0.218 0.096 18.415 2.786 0.976 0.536 1.54 1981 .0157 129594. 1.246 0.236 0.977 1.147 0.207 0.861 0.236 0.061 20.169 3.081 0.976 0.356 1.55 1980 .0119 135705. 0.994 0.752 0.977 1.127 0.221 0.861 0.249 0.050 9.505 9.597 0.976 0.223 2.48 1979 .0085 141485. 3.842 0.938 0.980 1.169 0.255 0.861 0.264 0.062 48.095 12.050 0.980 0.502 2.41 1978 .0087 146952. 3.894 1.039 0.980 1.212 0.259 0.861 0.279 0.065 48.843 13.103 0.980 0.531 2.46 1977 .0061 152125. 3.955 1.083 0.980 2.652 0.280 0.861 0.295 0.055 49.862 13.867 0.980 0.380 2.50 1976 .0042 157017. 3.987 1.201 0.984 2.725 0.294 0.861 0.312 0.039 50.620 15.810 0.986 0.275 2.71 1975 .0030 161645. 5.080 1.239 0.984 2.799 0.325 0.861 0.329 0.031 64.580 16.947 0.986 0.240 2.73 1974 .0023 166023. 5.533 0.184 0.981 2.875 0.359 0.861 0.348 0.024 63.731 5.217 0.981 0.159 2.90 1973 .0018 170164. 5.632 0.187 0.981 2.958 0.359 0.867 0.368 0.018 65.269 5.316 0.981 0.123 2.92 1972 .0013 174081. 5.723 0.063 0.986 3.043 0.353 0.872 0.389 0.013 68.072 1.803 0.982 0.087 3.87 1971 .0040 177787. 8.571 0.000 0.986 4.754 0.356 1.668 0.411 0.062 77.265 0.000 0.980 0.302 3.87+ ______ ______ ______ ______ ______ ______  0.483 0.193 0.492 0.127 2.001 9.317