NHTSA’s mission is to prevent motor vehicle crashes and reduce injuries, fatalities, and economic losses associated with these crashes. To carry out this mission, NHTSA conducts a range of safety-related activities, including: providing guidance and other assistance to states to help address setting vehicle safety standards; investigating possible safety defects and taking steps to help ensure that products meet safety standards and are not defective (through recalls if necessary); collecting and analyzing data on crashes; and traffic safety issues, such as drunk driving and distracted driving. NHTSA also develops uniform guidelines for states’ highway safety programs. In the past, these guidelines were referred to as standards, and if a state failed to implement these standards, DOT could withhold a percentage of federal-aid highway funds apportioned to the state. As shown in figure 1, this authority changed in 1976 when legislation limited NHTSA’s authority to withhold apportioned funds. Since that change, states have been able to choose whether or not to follow the guidelines in developing their highway safety programs. NHTSA’s guideline on state motor vehicle inspection programs, included in its Uniform Guidelines for State Highway Safety Programs, recommends that states should have a program for periodic inspection of all registered vehicles to reduce the number of vehicles with existing or potential conditions that may contribute to crashes or increase the severity of crashes that do occur, and should require the owner to correct such conditions. We found that 16 states operate periodic motor vehicle inspection programs. See figure 2 below. These states develop the specific rules that govern their programs. For example, 11 of the 16 states with inspection programs require an annual vehicle safety inspection, three states require a biennial inspection, and two states require time frames other than annual or biennial. Further, some states allow certain vehicles to be exempted from the safety inspections, such as newer model vehicles (up to 5 years from the model year) or vehicles at least 25 years old and registered as historical vehicles. Some states couple the safety inspection with emissions inspections. Vehicle safety inspection programs are administered by the state motor vehicle administration, department of transportation, or law enforcement agency, and in all of the states, except Delaware, state-licensed private inspection stations perform the inspections. The number of these private inspection stations per state ranges from around 295 (Rhode Island) to 17,000 (Pennsylvania). With a few exceptions, states do not limit the number of private inspection stations that may participate in the safety However, inspection program; it is typically a market-driven process.states require these inspection stations to obtain certification or licenses from the state. Delaware operates four state-run safety inspection sites. The fees charged to vehicle owners for safety inspections are mostly set by the state, though five states allow a market-driven fee which is set by individual inspection stations. State officials we spoke with provided information on the fees collected from drivers at the time of inspection. These fees ranged from $0 (Delaware) to $55 (Rhode Island, but this includes an emissions inspection). In addition to the guideline for states on periodic motor vehicle inspection, NHTSA has issued Vehicle In Use Inspection Standards, which set inspection criteria for several vehicle systems.system standards for brakes (hydraulic, vacuum, air, electric and service brakes), steering, suspension, tires, and wheel assemblies. For example, the standards specify that tread on a tire shall not be less than two thirty– seconds (2/32”) of an inch deep and provides an inspection procedure for examining the tire for this depth. These minimum standards apply to all states that choose to implement a vehicle safety inspection program. However, states with programs include more vehicle systems in their inspections than are specified in the standards. For systems not covered by these standards, each state determines what will constitute a passed or failed component. Examples of other systems generally incorporated into state vehicle safety inspections are lighting (such as headlights, brake lights, and turn signals), seatbelts, horns, windshields, wiper blades and the vehicle’s undercarriage. According to officials in 15 states with existing vehicle safety inspection programs whom we interviewed, these programs help improve the condition of vehicles; these officials point to data on the number of failed inspections as evidence of the safety benefit of these programs. Officials whom we interviewed from all 15 states said their programs help identify vehicles with safety problems and remove these unsafe vehicles from the roadways or compel owners to make repairs that otherwise might not be performed. Most of these states (12 of 15) collect data on the number of vehicles that fail inspection—the failure rate—and officials from 9 of these states cited their failure rate data to demonstrate the effectiveness of their programs. For example, Pennsylvania officials provided 2014 data showing that more than 529,000 vehicles (about 20 percent of the state’s 2.7-million registered vehicles) underwent repairs in order to pass inspection after initially failing. Virginia officials told us they believed that their state’s roadways were safer because their program identified safety problems in over 1.4 million—or 19 percent—of the state’s 7.5-million vehicles, in 2014. According to Virginia officials, 700,000 of those vehicles were rejected for brake-related issues such as worn, contaminated, or defective linings or drums, disc pads, or disc rotors. Safety problems most frequently found in other states in 2014 included: problems with glass, which resulted in 47,172 failed inspections in Utah; malfunctioning brake lights, which resulted in more than 13,000 failed inspections in Delaware; and tire deficiencies, which resulted in almost 6,000 failed inspections in Rhode Island. Additionally, officials in three states said that vehicle safety inspections are valuable because the average age of passenger vehicles is increasing and, in some areas, weather conditions and roadway treatments such as salt may contribute to vehicle deterioration. For example, Rhode Island officials stated that their inspection program is necessary in part because the state’s snow and icy weather requires road treatments that can corrode a vehicle’s chassis, steel brake lines, suspension, steering linkages, and ball joints. Further, these officials said that their inspection program is important because vehicles are staying in service longer—with some cars accruing more than 300,000 miles— exposing vehicle systems to more use and risk of developing safety issues. DOT data show that the average age of passenger vehicles has consistently increased from 1995 to 2013, from an average age of 8.4 to 11.4 years. Similarly, Vermont and West Virginia officials told us that their states’ snow and associated road treatments, coupled with rough terrain and poor roadways, increase vehicle deterioration. They said that their programs mitigate seasonal weather challenges by reducing the number of unsafe cars in use. Despite the consensus among the state inspection program officials we interviewed that these programs improve vehicle condition, research remains inconclusive about the effect of safety inspection programs on crash rates. There is little recent empirical research on the relationship between vehicle safety inspection programs and whether these programs reduce crash rates. What is available has generally been unable to establish any causal relationship.on vehicle safety inspection programs in 1990, there have been three econometric studies conducted examining the relationship between vehicle inspections and crashes in the U.S. and three studies examining these programs in other countries. Among the three studies of U.S. vehicle inspection programs, none were able to establish a statistically significant effect of safety inspection programs on crashes involving either fatalities or injuries. Specifically, the studies examined crash rates in all 50 states and did not find statistically significant differences in crash rates in states with inspection programs compared to those without. International studies have also not been able to establish a link between Since GAO last conducted a review safety inspection programs and crash rates involving either fatalities or injuries. For example, only one study suggested that safety inspections potentially reduce the likelihood of crashes, but noted the magnitude of the reduction could not be clearly established.information on each of the studies. See appendix III for more While our literature review did not yield any studies establishing that vehicle safety inspections reduce crashes, this does not necessarily demonstrate that inspections do not have such an effect. Nationwide studies involving crashes related to vehicle component failure are hindered, in part, due to a lack of nationwide crash data. There is no comprehensive database for all police reported crashes in the United States. NHTSA maintains two data sources that capture some vehicle crash incidents related to component failure. NHTSA’s Fatality Analysis Reporting System (FARS) is a census of all fatal traffic crashes in the United States that provides uniformly coded, national data on police- reported fatalities, and contains information on crashes in which vehicle component failure was noted, but is limited to crashes involving fatalities. NASS-GES is a nationally representative sample of police-reported motor vehicle traffic crashes, which is also uniformly coded and contains information on crashes in which vehicle component failure was noted in the police report. However, the sample is not set up to be representative at the state level; therefore, it cannot be used to compare states with and without safety inspection programs. Some researchers have used FARS in their analyses in order to perform state-by-state comparisons, but detecting the effect of inspection programs on crash rates is difficult because few crashes involve fatalities, and relatively few of those fatal crashes are noted in police reports as having vehicle component failure as a potential contributing factor. According to our analysis of NHTSA’s NASS-GES crash data from 2009 through 2013, crashes with noted vehicle component failure constituted around 2 percent of all crashes nationwide. We also found that the three most common failures were related to 1) tires, 2) brakes, and 3) steering. These categories make up the majority of failures reported with the next biggest category being “other.” (See fig. 3.) These components are inspected as part of all state inspection programs. In addition to looking at NASS-GES data, we attempted to examine crash rates before and after the elimination of safety inspection programs in four states and D.C., but were able to get sufficient crash data for two of these states, New Jersey and Oklahoma.vehicle component failure were generally between 2 and 3 percent of all crashes and varied little from year to year, even after the elimination of the inspection programs. We also calculated the crash rate—controlling for vehicle miles traveled—and found that the rate did not significantly change for either state. However, this analysis does not provide sufficient In both cases, crashes involving evidence to conclude that inspection programs did not have an effect on crash rates because additional factors—such as implementation or increased enforcement of traffic safety laws—could influence crash rates. The number of crashes related to vehicle component failure may also be generally underreported. Some literature and safety advocate organizations we spoke with noted that police officers filling out accident reports often do not have the time and resources to conduct a thorough vehicle check to determine if a vehicle component failure contributed to the crash. Other factors, such as driver behavior, may be more easily ascertained. For a 2008 NHTSA crash causation survey, researchers conducted thorough investigations of over 5,000 crashes over a 2-year period (2005—2007) to determine factors that contributed to the crashes. While this study did not identify vehicle component failure as necessarily the cause of the accident, vehicle component failures were found to be present in 6.8% of crashes. The crash causation survey utilized a more comprehensive mechanical examination of the vehicle(s) involved in crashes than the police accident reports used as the data collection instrument for the NASS-GES crash data. The results of the crash causation survey suggest that the percentage of crashes related to vehicle component failure is higher than the estimates produced by the NASS-GES because of the more detailed analysis of the vehicles involved in the crashes. States with vehicle safety inspection programs generally do not directly track the costs of managing and overseeing such programs. Officials from 8 of the 15 states with vehicle safety inspection programs we interviewed told us they do not track the cost of their vehicle inspection program. Officials from several of these states explained that costs for the inspection program cannot be broken out, because the costs for operating the inspection program are co-mingled with other programs or activities. For example, in New York, North Carolina, and Vermont, officials told us the staff who oversee the safety inspection programs also perform oversight of the emissions testing program, motorcycles or heavy-duty vehicles inspections, or have other state DOT duties. Consequently, the administrative costs for programs and activities were co-mingled. Similarly, officials from seven states reported tracking their program costs, but several of them also acknowledged some cost estimates included costs from other programs, since inspection program staff and overhead may be multi-tasked for other related programs. Funding for vehicle safety inspection programs comes from general state funding or through fees related to safety inspections. States typically receive some of the fee charged to drivers for safety inspections, while the remainder is retained by the inspection station. As explained by state officials, generally the amount that goes to the state is between $0 and $5 per inspection, though some states receive greater amounts with the most being $33.25. In some cases, states generate revenue by selling inspection stickers to the stations that conduct the inspection; these stickers are used to indicate that a vehicle has passed the inspection. States may also collect fees at the time of vehicle registration. These revenue sources may go to the state’s general fund, to other funds or departments (such as a highway maintenance fund), or to the larger programmatic department (state patrol or department of transportation), before being allocated to the inspection program. No state reported using federal funds to support its inspection program. NHTSA officials also said that no state had ever applied to use federal funding for a safety inspection program. Officials in the 15 states we spoke with primarily cited oversight and paper-based data systems as challenges they have faced when operating their vehicle safety inspection programs. Eleven of 15 states cited oversight efforts as a challenge. Oversight efforts involve addressing or preventing fraudulent behavior and ensuring that private inspection stations perform inspections in compliance with program requirements. To conduct oversight, states with private inspection stations generally perform some combination of routine, random, and covert audits. Because the inspection station is a private entity, states do not have direct control over how inspections are performed. For example, one state official said it can be a challenge to ensure that stations do not attempt to make unneeded repairs for profitable gain, while officials in a second state said it was a challenge to ensure that stations do not intentionally pass vehicles that should have failed the inspection. Officials in a third state explained that it is challenging to ensure thoroughness and quality of the inspection because doing so is a labor-intensive process. Similarly, officials in four of the five states that we spoke with that had eliminated programs told us that oversight efforts were also a challenge for them in operating their programs. For example, officials in one state told us that inspection stations were able to make more money by providing other automotive services and believed the safety inspections were not as profitable. Consequently, some inspection station mechanics issued inspection stickers without properly conducting inspections. In addition, some states cited challenges with inadequate staffing resources for oversight efforts. For example, officials from four states mentioned that they had relatively few state auditors to oversee their safety inspection programs. According to officials in one state, oversight can be a particular problem because private inspection stations can span thousands of miles, and it can be difficult to retain qualified state personnel if state wages are relatively low. Four of 15 states cited their paper-based data systems as a challenge. Paper-based inspection data systems can be inefficient and, according to some state officials, can limit states’ ability to monitor their programs. Generally, in a paper-based data system, private inspection stations record inspection results on paper forms rather than into an electronic database. Officials in one state said they would like an electronic database because inspection station results would be more quickly shared with the state, resulting in better program monitoring. These officials said they would first need to ensure that the benefits of an electronic database outweigh the costs and was a viable solution before requiring inspection stations to use it. Officials in another state physically scan and enter paper-based data received from inspection stations into the state’s database, a process that they said is time consuming. To help manage the state’s data- entry work flow, officials limit the number of safety inspections that inspection stations may conduct in a single day. These officials said that the lack of Internet access at some of the inspection stations in the state made it difficult to require the use of an electronic inspection database. Other states with paper-based systems do not collect statewide inspection data, preventing the state from analyzing data and determining, for example, the number of vehicles that fail inspections in a given year. Officials from one of these states cited a lack of funds as a major impediment to creating an electronic data system, and an official from the other state told us they were preparing a request for proposals to develop an electronic database. Other Challenges: State officials mentioned additional challenges, including state legislatures’ attempts to eliminate or alter programs (two states) and customer service challenges or general public irritation with the program (two states). For example, officials in two states told us they either relaxed or eliminated some non-safety related standards (such as using certain tools to check headlight aim) or exempted newer-model vehicles from safety inspections as a compromise with state legislatures to continue their programs. With regard to customer service challenges, officials in two states told us it was challenging for them to deal with customers who complained when their vehicle failed the inspection, had to be re-inspected, or they endured long wait times. Literature that we reviewed and other stakeholders whom we interviewed, including representatives from safety groups, vehicle manufacturer industry groups, and DOT officials, also cited challenges that states face in operating their programs. Four studies cited oversight challenges. For example, a 1999 study noted that inspectors can either intentionally or unintentionally fail to report safety problems—sometimes to minimize the level of trouble to customers and increase the number of inspections performed. A 2008 state study found that one of the major criticisms of safety inspection programs is the difficulty that one state had in ensuring the quality and uniformity of inspections. The study stated that a thorough inspection, if performed to state regulations, should take between 15 and 30 minutes, according to program managers and industry representatives. However, according to the study, safety inspections in this state were taking 5 minutes, on average, raising questions about whether consumers’ vehicles were receiving thorough inspections. In addition, four stakeholders told us that state legislatures’ attempts to eliminate states’ programs either were or may be a challenge for states. Also, three stakeholders told us that public frustration associated with what the public perceives as unneeded repairs or the personal inconvenience vehicle owners feel when having to get their vehicles inspected either were or may be challenges for states. Some states have taken action to address their challenges, including implementing more stringent program rules, preparing manpower studies, and developing electronic database systems. Officials in one state told us that in 2012, they implemented stricter program rules for inspection stations to follow in an attempt to reduce fraudulent behavior (specifically, issuing stickers for vehicles that should have failed the inspection). In addition, officials in a second state said they recently added requirements that inspection station mechanics use fingerprint scanners for proper identification before performing inspections. To address challenges with staffing resources, officials in a third state told us they completed a manpower study to better identify the resources needed to operate their program. An official in another state told us that state officials were currently developing a request for proposals to create an electronic database system to replace its paper-based system. While some states have tried various ways to address their program challenges, other states have eliminated their vehicle safety inspection programs altogether. Since we last reported on vehicle safety inspections in 1990, five states and the District of Columbia have dropped their programs, some citing a lack of evidence proving the program’s effectiveness or saving financial resources as reasons. For example: In 2001, an Oklahoma Senate Press Release stated there was no evidence that vehicle safety inspection programs resulted in decreased highway accidents or injuries statewide and that eliminating the program would save Oklahomans $12 million. In 2009, the District of Columbia eliminated its safety inspection program primarily because there was no available data to show that the program was beneficial, according to a District official. For example, a District official told us that an analysis of crash data before the program was eliminated showed that the majority of vehicle accidents resulted from driver behavior, not from vehicular mechanical failure. In 2010 when New Jersey eliminated its program, the New Jersey Motor Vehicle Commission Chief Administrator announced that with a lack of conclusive data on program effectiveness and with the current (2010) fiscal crisis, New Jersey could not justify the program’s expense, and that dropping the program would yield an estimated annual savings of $17 million. Officials in all 15 states with inspection programs that we spoke with told us that additional guidance and information from NHTSA would help in operating their programs. The majority of state officials (11 of 15) would like more guidance in the area of new vehicle safety technologies in order to determine how and whether new technologies should be incorporated into their inspection programs. The example most frequently cited by state officials was light-emitting diode (LED) brake lights. LED brake lights have multiple “light-emitting diodes” that contribute to the visibility of the light. See figure 4 below for a diagram of an LED light. The number of LEDs in a light can vary, depending on the vehicle manufacturer or model. According to state officials, they do not know how many diodes, if any, could malfunction before the light is considered unsafe, making it difficult for them to set pass or fail criteria for LED lights. Since brake lighting is critical to alert other drivers to changing conditions, it is important for states with inspection programs to have criteria to judge whether lights are working sufficiently well. Officials in three states also noted that such criteria are important because failing a car on the basis of individual diodes being out can result in a costly repair for consumers ranging from a few hundred to several thousand dollars, depending on the vehicle. State officials provided a range of criteria they have chosen to use for LED brake lights: 50% of the diodes must function to pass inspection (5 states), 70% must function (1 state), 100% must function (3 states), and not yet specifically addressed in the inspection program (1 state). Federal Motor Vehicle Safety Standard No. 108: Lamps, reflective devices, and associated equipment, 49 C.F.R. § 571.108. NHTSA could sponsor research in the area of LED brake lighting as it has done in the past that might be helpful to states. Further, officials in two states said that they are concerned about how their programs may be impacted by new autonomous vehicle technologies. Officials did not state specific concerns, but said that with new advanced vehicle technologies coming on the market, it is not clear how or what they should be inspecting. We have previously reported that automobile manufacturers have begun to equip some newly manufactured vehicles with sensor-based crash avoidance and autonomous technologies intended to prevent accidents.officials from these two states noted that such technologies may add a new layer to their inspection programs if the state decides the technologies need to be included in inspections. State officials in eight states with safety programs we interviewed also said that additional information from NHTSA on new safety technologies required by the agency’s safety standards for vehicle manufacturers would help them in operating their inspection programs. These state officials told us they generally track new vehicle safety standards implemented by NHTSA, but it is not always clear to program officials whether or how new standards might be incorporated into their inspection programs. Two recent vehicle standards cited by state officials were the requirements for tire-pressure monitoring systems (three state officials) and back-up cameras (two state officials). Specifically, these states would like guidance on whether they should check to see that these technologies are functioning correctly for vehicles that were manufactured with the technologies. Officials in one state told us that their state required the tire-pressure monitoring system to work and then eliminated that requirement because the system often malfunctioned and the inspectors could readily check whether the tires are properly inflated and holding air. A 2013 study contracted by NHTSA to gather information for updating inspection standards found “State directors welcomed the suggestion that, when NHTSA issues a new regulation, the rulemaking be accompanied by guidance on how to inspect a vehicle to ensure that the required equipment is still functioning.” However, the last update to the standards was in 1979, thus technologies that have been developed since that time—such as anti-lock brake systems—are not included. NHTSA officials told us that the determination of whether or how to include new vehicle safety technologies in inspection programs should be made by the states. Further, NHTSA conducts research that could be useful to states with inspection programs, but state officials may not be aware of this information. For example, in April 2015, NHTSA issued the results of a defect investigation on brake lines, which recommended to consumers who drive vehicles from model year 2007 and earlier and live in cold- weather states to have a qualified mechanic inspect brake lines and other components under the vehicle at least twice a year, which is more frequent than the most strict state inspection requirements. Although the recommendation was not directed at state inspection officials, this information could help state inspection officials identify such problems during their inspections. However, NHTSA did not disseminate this information directly to states with inspection programs. According to officials from the American Association of Motor Vehicle Administrators (AAMVA)—the national group representing motor vehicle and law enforcement agencies, which administer safety inspection programs in states—they would share this type of information from NHTSA with their members. However, the AAMVA officials were not aware of this study. According to NHTSA officials, NHTSA issues press releases to the media and stakeholders on a regular distribution list, but AAMVA is not currently on this distribution list. According to NHTSA officials, there are no NHTSA staff designated to answer questions related to state inspection programs or disseminate relevant information to program officials because agency resources are currently focused on areas that have a greater impact on crash rates, such as driver behavior. NHTSA officials also noted that current evidence on vehicle safety inspection programs does not warrant a more prescriptive approach and that state officials should make determinations on what is most effective for their individual programs. Considering the variation among state programs and state needs it seems appropriate for states to determine much of their vehicle safety inspection program’s structures. However, state vehicle safety inspection program officials sometimes have questions about incorporating new technologies in their programs. Given that NHTSA has a guideline recommending that states implement vehicle inspection programs and that the agency’s mission includes assisting states with traffic safety programs, it is reasonable that state officials would look to NHTSA for guidance when these questions arise. While NHTSA does not dedicate staff to vehicle inspection issues, the agency has a broad range of vehicle technical experts in various parts of the organization who are knowledgeable about related issues. For example, NHTSA officials said the agency currently has 20 engineers who work on Federal Motor Vehicle Safety Standards that are relevant to vehicle inspection guidelines, along with 10 support professionals, such as economists and lawyers. Although NHTSA could update or produce additional regulation, Executive Order 13563 states that agencies should be identifying and assessing available alternatives to regulation including providing information upon which choices can be made. Establishing a communication channel, such as by designating a point of contact, could provide information transfer between knowledgeable NHTSA staff and state vehicle inspection program officials, and could help state inspection program officials operate their programs more effectively. Once established, such a channel would not necessarily require extensive NHTSA resources. For example, NHTSA could leverage the communication channel that AAMVA currently has with states, or set up a web-based forum through which state officials can ask questions, receive information from NHTSA, and share information with other states on how they are addressing new vehicle technologies and standards in their programs. While the benefits and costs of state vehicle inspection programs are difficult to quantify, state program officials we spoke to are confident that their programs improve vehicle safety, despite the challenges they face in operating the programs. However, some state officials told us they sometimes have questions about new technologies and other issues related to vehicle safety, and have not been able to get clear answers from NHTSA. With no recent federal guidance, state officials have implemented different criteria or chosen not to include new technologies in their inspection programs, potentially reducing the safety benefits of their inspection program. Further, NHTSA’s work in the areas of Federal Motor Vehicle Safety Standards and defects investigation touches on vehicle component and safety information that could be useful to state vehicle safety inspection program officials, but this information is not being provided directly to these officials nor to the national group that represents these officials. NHTSA’s decision to not devote significant resources to state vehicle inspection programs is consistent with research showing that vehicle component failures are a relatively minor contributor to traffic crashes. However, establishing a communication channel to answer questions from state officials and convey information could assist states in improving their vehicle safety inspection programs. To minimize resources needed to establish and maintain a communication channel, NHTSA could potentially create a web-based forum to share information and respond to questions and collaborate with AAMVA to disseminate information to state officials. To improve assistance to states in regard to the periodic motor vehicle inspection guideline, the Secretary of Transportation should direct the Administrator of NHTSA to establish and maintain a communication channel with states to convey relevant information related to vehicle inspections and respond to questions from state safety inspection program officials. We provided a draft of this report to DOT for review and comment. DOT provided written comments, which are reprinted in appendix V. In its written comments, DOT stated that NHTSA agreed with our recommendation, and supports our conclusion that establishing a communication channel with state vehicle safety inspection program officials would be beneficial. We are sending copies of this report to the appropriate congressional committees, and the Secretary of Transportation. This report will also be available at no charge on the GAO website http://www.gao.gov. If you or your staff have any questions about this report, please contact me at (202) 512-2834 or flemings@gao.gov. Contact points for our Offices of Congressional Relations and Public Affairs may be found on the last page of this report. GAO staff who made key contributions to this report are listed in appendix VI. We conducted a review of state motor vehicle inspection programs and National Highway Traffic Safety Administration’s role in assisting these programs. This report assesses: 1) what is known about the safety benefits and costs of operating state vehicle safety inspection programs, 2) any challenges states have faced in operating these programs, and 3) any actions NHTSA could take to assist states with these programs. To identify what is known about the costs and safety benefits of state vehicle inspection programs, we conducted a literature search for studies that analyzed relationships between safety inspections and outcomes, such as crash rates, vehicle component failures, and vehicle fleet age. We limited our literature search to those articles and reports published since 1990—the last time GAO conducted a comprehensive literature review. We identified existing studies from peer-reviewed journals, government reports, trade publications, and conference papers based on searches of various databases, such as ProQuest, Academic OneFile, and Transportation Research International Documentation. Search parameters included studies across the United States and in other countries. We also conducted interviews with organizations that assist states with traffic safety efforts and asked them to recommend additional research. The literature review parameters and interviews resulted in 185 abstracts or studies. Of these, we determined that 29 studies appeared to be relevant—eliminating, for example, studies that focused on emissions inspections. We assessed the relevance and methodological quality of the selected studies by performing an initial review of the findings (here we eliminated any studies based on data from before 1980), and then performed an independent assessment of the study’s methodology. After these reviews, we determined that 6 studies published from 1992 through 2013 were sufficiently reliable for the research objective on the safety benefits and costs of operating state vehicle safety inspection programs (see appendix III) and 4 studies were sufficiently reliable for the research objective on any challenges that states face in operating these programs. To determine what is known about safety benefits of state vehicle inspections, we also analyzed crash data. Because of known data limitations raised in the studies we reviewed during the literature search, we attempted to compare crash rates related to vehicle component failure before and after program elimination in states that eliminated their inspection program since 1990. Six states fit this criterion: South Carolina (1995), Arkansas (1998), Oklahoma (2001), Washington D.C., (2009), New Jersey (2010), and Mississippi (2015). Because Mississippi dropped its program during the course of our assessment, we did not do a before and after comparison. For the other five states, we attempted to collect data on the number of crashes recorded in the state and the number of crashes recorded with vehicle component failures 5 years before and 5 years after program elimination. We were only able to obtain this data for two of the five states: Oklahoma and New Jersey. For Oklahoma we were able to obtain data for 1995-2013. We focused on the five years before and after 2001 when the program was eliminated to see if there was a difference in trend. Because New Jersey eliminated its program in 2010, we were not able to get 5 years of crash data after the program was eliminated. For New Jersey we reviewed data from 2005 to 2013. We also analyzed national level crash data from NHTSA’s National Automotive Sampling System General Estimates System (NASS-GES) for the years 2009-2013. NASS-GES consists of data collected from an annual sample of about 50,000 police accident reports and is statically weighted to be a nationally representative of all police-reported crashes that occur in the United States each year. We analyzed this data to determine the estimated number of total crashes with vehicle factors nationwide as well as the specific vehicle component failures that were reported, such as issues with brakes, tires, and steering. We express our confidence in the precision of estimates as 95 percent confidence intervals. This is the interval that would contain the actual population values for 95 percent of the NASS-GES samples that NHTSA could have drawn. Because of the sample design used to collect GES, we are limited to reporting trends on a national level and could not use this data to look at individual state trends. For each of these data sets, we interviewed relevant officials and analyzed the data for possible errors. We determined that these data were sufficiently reliable for the purposes of estimating the number of reported crashes that occur with vehicle component failures. To determine challenges states faced in operating their inspection programs and what actions, if any, NHTSA could take to assist states with their vehicle safety inspection programs, we reviewed federal and state policy and program documents related to inspection programs. We reviewed federal statutes, regulations, guidelines, and guidance documents, state laws authorizing safety inspection programs, state program reports, state officials’ testimony before their state legislators and state inspection guidance and manuals. We observed safety inspections in Delaware at a state-run inspection station and in Virginia at a privately owned and operated inspection station. In selecting these sites we worked with state officials to identify an inspection station where we could view an actual inspection take place. We conducted structured interviews with officials in 15 of the 16 states that currently have a safety inspection program. We attempted multiple times to speak with the one remaining state—New Hampshire—but were unsuccessful. We also interviewed state officials in five of six jurisdictions (four states and the District of Columbia) that eliminated their programs since 1990. South Carolina eliminated its program in 1995 and did not have any officials knowledgeable about the program. We also interviewed NHTSA officials, researchers at Carnegie Mellon University, and representatives from the American Association of Motor Vehicle Administrators, safety groups (Center for Auto Safety and Public Citizen), and automotive industry groups (Automotive Service Association, Auto Care Association, and Motor & Equipment Manufacturers Association). Article Sutter, David and Poitras, Marc (2002). The Political Economy of Automobile Safety Inspections. Public Choice, 133 (3-4), 367-387. Methodology Regression analysis using 1981-1993 panel data of 50 states. Conclusions Unable to establish a statistically significant effect of vehicle inspection program on fatalities or injury rates. Merrell, David, Poitras, Marc, and Sutter, Daniel (1999). The Effectiveness of Vehicle Safety Inspections: An Analysis Using Panel Data. Southern Economic Journal, 65 (3), 571-583. Regression analysis using 1981-1993 panel data of 50 states. Unable to establish a statistically significant effect of vehicle inspection program on fatalities or injury rates. Holdstock, J., Hagarty, D., & Zalinger, D. (1994). Review of a mandatory vehicle inspection program. Project report. Regression analysis using 1990-1991 data for 50 states, District of Columbia, and 10 Canadian provinces. Unable to establish a statistically significant effect of vehicle inspection program on fatalities or injury rates. Keall, M. D., & Newstead, S. (2013). An evaluation of costs and benefits of a vehicle periodic inspection scheme with six- monthly inspections compared to annual inspections. Accident Analysis & Prevention, 58, 81-87. Regression analysis using merged New Zealand crash data (2004-2009), licensing data (2003-2008), and inspection data (2003-2009). Going from annual to biannual inspections may reduce likelihood of crashes (8%) and the prevalence of vehicle defects (13.5%), but the wide confidence interval for the drop in crash rate (0.4–15%) indicated considerable statistical uncertainty. Christensen, Peter and Elvik, Rune (2007). Effects on Accidents of Periodic Motor Vehicle Inspection in Norway. Accident Analysis and Prevention 39, 47-52. Observational study using insurance data and 1998-2002 inspection data in Norway. Inspections improved the technical condition of inspected cars, but did not have a statistically significant effect on crash rates. The study’s findings suggested that following inspections, the accident rate of inspected cars did not decline, but rather showed a weak tendency to increase. Fosser, Stein (1992). An Experimental Evaluation of the Effects of Periodic Motor Vehicle Inspection on Accident Rates. Accident Analysis and Prevention 24 (6), 599-612. Experimental design over 4 years (1986- 1990) in Norway. Inspection improved the technical condition of inspected cars, but the differences found in technical condition had no influence on accident rates. Appendix IV: Estimated Number of Crashes Listed with Vehicle Component Failure 2009- 2013 with Lower and Upper Bound 95% Confidence Intervals (CI) In addition to the contact named above, Sara Vermillion (Assistant Director), Carl Barden, Namita Bhatia Sabharwal, Timothy Bober, Melissa Bodeau, Jennifer Clayborne, Leia Dickerson, Amanda Miller, Sara Ann Moessbauer, Josh Ormond, Cheryl Peterson, Oliver Richard, Stephen Sanford, Amy Suntoke, Friendly Vang-Johnson, Michelle Weathers, and Jade Winfree made key contributions to this report.

Summary: In 2013, an estimated 5.7-million vehicle crashes resulted in approximately 32,700 fatalities and over 2.3-million injuries. One of NHTSA's guidelines to help states optimize the effectiveness of highway safety programs recommends that each state have a program to periodically inspect all registered vehicles to reduce the number of vehicles with conditions that may contribute to crashes or increase the severity of crashes. GAO was asked to review these state programs and NHTSA's assistance to states. This report assesses: 1) what is known about the safety benefits and costs of operating state vehicle safety inspection programs, 2) challenges that states have faced in operating these programs, and 3) actions NHTSA could take to assist states with these programs. GAO analyzed NHTSA 2009—2013 data and state data for crash trends related to vehicle component failure; reviewed studies that analyzed relationships between safety inspections and outcomes; and interviewed officials in 15 states that have inspection programs. GAO also interviewed officials in 5 states that eliminated their programs since 1990, NHTSA officials, and representatives from safety groups and automotive industry groups. According to officials GAO interviewed from 15 state vehicle safety inspection programs, these programs enhance vehicle safety; however, the benefits and costs of such programs are difficult to quantify. State officials told GAO that inspections help identify vehicles with safety problems and result in repair or removal of unsafe vehicles from the roads. For example, Pennsylvania state data show that in 2014, more than 529,000 vehicles (about 20 percent of vehicles in the state) failed inspection and then underwent repairs to pass. Nationwide, however, estimates derived from data collected by the Department of Transportation's (DOT) National Highway Traffic Safety Administration (NHTSA) show that vehicle component failure is a factor in about 2 to 7 percent of crashes. Given this relatively small percentage as well as other factors—such as implementation or increased enforcement of state traffic safety laws—that could influence crash rates, it is difficult to determine the effect of inspection programs based on crash data. Studies GAO reviewed and GAO's analysis of state data examined the effect of inspection programs on crash rates related to vehicle component failure, but showed no clear influence. Finally, many states do not directly track the costs of operating safety inspection programs because costs may be comingled with other inspection programs, such as emissions. State safety inspection program officials GAO interviewed primarily cited the oversight of inspection activities and paper-based data systems as challenges they have faced in operating vehicle safety inspection programs. For example, officials in 11 of the 15 states with programs GAO interviewed cited oversight efforts as a challenge, including ensuring that private inspection stations were conducting inspections consistent with program requirements, and officials in 4 of the 15 states also said that paper-based data systems can hinder oversight efforts. To address challenges, some states have taken actions such as implementing more stringent program rules and exploring the development of electronic data systems. Other states have eliminated their inspection programs altogether. Program officials in all 15 states said that additional information from NHTSA—for example, information related to new vehicle safety technologies—would help in operating their programs. However, there is no designated channel for communication between NHTSA and program officials. Several state officials noted that they would like more information on new technologies such as light-emitting diode (LED) brake lights. State officials also said that it is not clear whether or how to inspect new safety technologies, such as tire pressure monitoring systems, required by NHTSA for new vehicles. Without information, states have implemented different inspection pass-fail criteria or chosen not to include new technologies in their inspections, potentially reducing the safety benefit of their programs. NHTSA officials told GAO they have adopted a hands-off approach to state vehicle inspection programs because the agency devotes its resources primarily to areas that contribute more heavily to crashes, such as driver behavior. However, consistent with NHTSA's mission to assist states in implementing traffic safety programs, improving communication with state officials on vehicle safety issues could help these officials in operating their inspection programs. DOT should establish a communication channel with states to convey relevant information to state safety inspection officials and respond to their questions. DOT officials reviewed this report and agreed with GAO's recommendation.