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Vehicle inspection & maintenance (I/M) programs

Health Factors: Air & Water Quality
Decision Makers: State Government Federal Government
Evidence Rating: Some Evidence
Population Reach: 20-49% of WI's population
Impact on Disparities: Likely to increase disparities

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Description

Vehicle inspection and maintenance (I/M) programs require scheduled testing of a vehicle’s tailpipe and evaporative emissions to determine the effectiveness of its emission controls. I/M programs are federally mandated under the 1990 Amendments to the Clean Air Act for areas with particularly poor air quality; program areas are identified based on criteria such as air quality classification, population, and/or geographic location (US EPA-IM Best practices). Programs can also be implemented at the discretion of state and local governments. Program design varies by location, although most I/M programs for modern, advanced technology vehicles use on-board diagnostic computer tests (US EPA-State IM programs 2003).

Expected Beneficial Outcomes

Reduced emissions
Improved air quality

Evidence of Effectiveness

There is some evidence that vehicle inspection and maintenance (I/M) programs reduce emissions from light duty cars and trucks (Dehart-Davis 2002, Harrington 2000, Washburn 2001, Eisinger 2005, Samoylov 2013, CVEIMP 2001Austin 2009). However, additional evidence is needed to confirm effects of I/M programs for modern, advanced technology vehicle fleets.

I/M programs can improve air quality by reducing carbon monoxide, carbon dioxide, hydrocarbon (Dehart-Davis 2002, Washburn 2001, Eisinger 2005) and nitrogen oxide emissions (Samoylov 2013). Enhanced I/M programs, similar to Southern California’s program, can reduce older light duty motor vehicles’ hydrocarbon exhaust emissions by 14-28% (Eisinger 2005), and cars’ carbon monoxide emissions by 26% (Dehart-Davis 2002). I/M programs may motivate pre-test repair work, improve repair effectiveness (Eisinger 2005), and create incentives for manufacturers to improve the emission characteristics of their vehicles, which would reduce emissions more than the amount attributed to existing programs (Harrington 2000).

Variable timing I/M programs that target vehicles with a higher likelihood of being high polluters, based on characteristics such as vehicle age, odometer reading, engine size, or previous emission test results, can be significantly more cost-effective than non-targeted annual or biennial retesting programs (Bin 2003, Washburn 2001, Moghadam 2010, Samoylov 2013).

Historically, I/M program costs have varied significantly with program design, stringency, and test equipment. Currently, however, most I/M programs use lower cost on-board diagnostic computer tests for modern vehicles (US EPA-State IM programs 2003). Inspection costs account for over two-thirds of the total cost of most programs, the remaining costs for actual vehicle repairs are borne by vehicle owners (Harrington 2000). In most states with I/M programs, vehicles that are not repaired cannot be registered (US EPA-IM Best practices); this may contribute to disparities in access to transportation.

Implementation

United States

As of 2013, the US Environmental Protection Agency (US EPA) lists vehicle inspection and maintenance programs in 31 states and Washington DC (US EPA-State IM Programs).

Wisconsin

The Wisconsin Department of Transportation website has information about the state’s vehicle emission testing program and locations where vehicles can be tested (US EPA-State IM Programs).

Implementation Resources

US EPA-IM Best practices - US Environmental Protection Agency (US EPA). Cars and light trucks: Inspection & maintenance (I/M): Best practices. Accessed on November 24, 2015
US EPA-OBD - US Environmental Protection Agency (US EPA). OBD and inspection and maintenance. Accessed on November 23, 2015

Citations - Description

US EPA-IM Best practices - US Environmental Protection Agency (US EPA). Cars and light trucks: Inspection & maintenance (I/M): Best practices. Accessed on November 24, 2015
US EPA-State IM programs 2003 - US Environmental Protection Agency (US EPA). Cars and light trucks: Inspection & maintenance (I/M) state status. 2003. Accessed on March 1, 2016

Citations - Evidence

Austin 2009 - Austin TC, McClement D, Roeschen JD. Evaluation of the California Smog Check Program Using Random Roadside Data. California Air Resources Board, California Bureau of Automotive Repair. Report No. SR09-03-01. 2009. Accessed on February 29, 2016
Bin 2003* - Bin O. A logit analysis of vehicle emissions using inspection and maintenance testing data. Transportation Research Part D: Transport and Environment. 2003;8(3):215–27. Accessed on November 30, 2015
CVEIMP 2001* - Committee on Vehicle Emission Inspection and Maintenance Programs (CVEIMP), Board on Environmental Studies and Toxicology, Transportation Research Board, National Research Council. Evaluating vehicle emissions inspection and maintenance programs. National Academies Press; 2001. Accessed on March 1, 2016
Dehart-Davis 2002* - Dehart-Davis L, Corley E, Rodgers MO. Evaluating vehicle inspection/maintenance programs using on-road emissions data: The Atlanta reference method. Evaluation Review. 2002;26(2):111-46. Accessed on December 8, 2015
Eisinger 2005 - Eisinger DS. Evaluating inspection and maintenance programs: A policy-making framework. Journal of the Air & Waste Management Association. 2005;55(2):147–62. Accessed on January 20, 2016
Harrington 2000* - Harrington W, McConnell V, Ando A. Are vehicle emission inspection programs living up to expectations? Transportation Research Part D: Transport and Environment. 2000;5(3):153-72. Accessed on February 4, 2016
Moghadam 2010* - Moghadam AK, Livernois J. The abatement cost function for a representative vehicle inspection and maintenance program. Transportation Research Part D: Transport and Environment. 2010;15(5):285–97. Accessed on November 23, 2015
Samoylov 2013 - Samoylov AV. Improvement of the efficiency of vehicle inspection and maintenance programs through incorporation of vehicle remote sensing data and vehicle characteristics. Atlanta: School of Civil and Environmental Engineering, Georgia Institute of Technology (GT); 2013. Accessed on November 24, 2015
US EPA-IM Best practices - US Environmental Protection Agency (US EPA). Cars and light trucks: Inspection & maintenance (I/M): Best practices. Accessed on November 24, 2015
US EPA-State IM programs 2003 - US Environmental Protection Agency (US EPA). Cars and light trucks: Inspection & maintenance (I/M) state status. 2003. Accessed on March 1, 2016
Washburn 2001* - Washburn S, Seet J, Mannering F. Statistical modeling of vehicle emissions from inspection/maintenance testing data: An exploratory analysis. Transportation Research Part D: Transport and Environment. 2001;6(1):21–36. Accessed on November 24, 2015

Citations - Implementation

US EPA-State IM Programs - US Environmental Protection Agency (US EPA). Cars and light trucks: Inspection & maintenance (I/M) - State program pages. Accessed on November 23, 2015

Page Last Updated

June 4, 2015

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