40 CFR § 51.371 - On-road testing.
On-road testing is defined as testing of vehicles for conditions impacting the emission of HC, CO, NOX and/or CO2 emissions on any road or roadside in the nonattainment area or the I/M program area. On-road testing is required in enhanced I/M areas and is an option for basic I/M areas.
(a) General requirements.
(1) On-road testing is to be part of the emission testing system, but is to be a complement to testing otherwise required.
(2) On-road testing is not required in every season or on every vehicle but shall evaluate the emission performance of 0.5% of the subject fleet statewide or 20,000 vehicles, whichever is less, per inspection cycle.
(3) The on-road testing program shall provide information about the performance of in-use vehicles, by measuring on-road emissions through the use of remote sensing devices or by assessing vehicle emission performance through roadside pullovers including tailpipe or evaporative emission testing or a check of the onboard diagnostic (OBD) system for vehicles so equipped. The program shall collect, analyze and report on-road testing data.
(4) Owners of vehicles that have previously been through the normal periodic inspection and passed the final retest and found to be high emitters shall be notified that the vehicles are required to pass an out-of-cycle follow-up inspection; notification may be by mailing in the case of remote sensing on-road testing or through immediate notification if roadside pullovers are used.
(b) SIP requirements.
(1) The SIP shall include a detailed description of the on-road testing program, including the types of testing, test limits and criteria, the number of vehicles (the percentage of the fleet) to be tested, the number of employees to be dedicated to the on-road testing effort, the methods for collecting, analyzing, utilizing, and reporting the results of on-road testing and, the portion of the program budget to be dedicated to on-road testing.
(2) The SIP shall include the legal authority necessary to implement the on-road testing program, including the authority to enforce off-cycle inspection and repair requirements (where applicable).
(3) Emission reduction credit for on-road testing programs shall be granted for a program designed to obtain measurable emission reductions over and above those already predicted to be achieved by other aspects of the I/M program. Emission reduction credit will only be granted to those programs which require out-of-cycle repairs for confirmed high-emitting vehicles identified under the on-road testing program. The SIP shall include technical support for the claimed additional emission reductions.
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