VEHICLE SAFETY 

INSPECTIONS

Improved DOT 

Communication Could 

Better Inform State 

Programs

Report to the Honorable Claire

McCaskill, U.S. Senate

August 2015

GAO-15-705

United States Government Accountability Office
United States Government Accountability Office

Highlights of GAO-15-705, a report to the

Honorable Claire McCaskill, U.S. Senate

August 2015

VEHICLE SAFETY INSPECTIONS

Improved DOT Communication Could Better Inform 

State Programs

Why GAO Did This Study

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.

What GAO Recommends

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.

What GAO Found

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 lightemitting 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 handsoff 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.

View GAO-15-705. For more information, 

contact Susan Fleming at (202) 512-2834 or 

flemings@gao.gov.
Page i GAO-15-705 Vehicle Safety Inspections

Letter 1

Background 3

Impact of Safety Inspections on Vehicle Safety Is Unclear as 

Benefits and Costs Are Difficult to Quantify 8

State Challenges Include Oversight and Paper-Based Data 

Systems 13

NHTSA Could Improve Communications with States 17

Conclusions 22

Recommendation 22

Agency Comments and our Response 22

Appendix I Objectives, Scope, and Methodology 24

Appendix II List of States that Have Required Vehicle Safety Inspections, 

1929-2015 27

Appendix III Studies Reviewed that Examine Vehicle Inspections and 

Crash Rates 28

Appendix IV Estimated Number of Crashes Listed with Vehicle 

Component Failure 2009-2013 with Lower and Upper Bound 95% 

Confidence Intervals (CI) 29

Appendix V Comments from the Department of Transportation 30

Appendix VI GAO Contacts and Staff Acknowledgements 31

Figures

Figure 1: History Timeline for State Vehicle Safety Inspection 

Programs 4

Contents
Page ii GAO-15-705 Vehicle Safety Inspections

Figure 2: States with Vehicle Safety Inspection Programs, July 

2015 6

Figure 3: Estimated Number of Crashes Related to Vehicle 

Component Failure, 2009—2013 11

Figure 4: Diagram of a Light-Emitting Diode (LED) light. 17

Abbreviations

AAMVA American Association of Motor Vehicle Administrators 

CI confidence interval

DOT Department of Transportation

FARS Fatality Analysis Reporting System 

LED light-emitting diode 

NASS-GES National Automotive Sampling System General Estimates 

System 

NHTSA National Highway Traffic Safety Administration 

This is a work of the U.S. government and is not subject to copyright protection in the 

United States. The published product may be reproduced and distributed in its entirety 

without further permission from GAO. However, because this work may contain 

copyrighted images or other material, permission from the copyright holder may be 

necessary if you wish to reproduce this material separately.
Page 1 GAO-15-705 Vehicle Safety Inspections

441 G St. N.W.

Washington, DC 20548

August 25, 2015

The Honorable Claire McCaskill

United States Senate

Dear Senator McCaskill:

Driving is one of the riskiest activities in which average Americans 

engage. In 2013, an estimated 5.7 million motor vehicle crashes resulted 

in approximately 32,700 fatalities and over 2.3 million injuries.1 The 

Department of Transportation’s (DOT) National Highway Traffic Safety 

Administration (NHTSA) was established in 1970 with a mission to save 

lives, prevent injuries, and reduce the economic costs that result from 

such crashes.2 As part of this mission, NHTSA supports state efforts to 

improve traffic safety and issues guidelines to help states optimize the 

effectiveness of highway safety programs at the state and local level. One 

of these guidelines recommends that each state 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.3 Between 1967 

and 1976, DOT could withhold a percentage of federal-aid highway funds 

apportioned to a state that did not implement a periodic motor vehicle 

inspection program; the mid 1970’s was the high-water mark for these 

programs, with 31 states and the District of Columbia implementing 

programs. Since 1976, after legislation limited NHTSA’s authority to 

withhold federal-aid highway funding, the number of states with programs 

has declined. As of July 2015, we found 16 states with periodic inspection 

programs. You asked us to review state motor vehicle inspection 

programs and NHTSA’s role in assisting these programs.4

 1

National Highway Traffic Safety Administration. Quick Facts 2013. DOT HS 812 100, 

December 2014.

This report 

2

Highway Safety Act of 1970, Pub. L. No. 91-605. 84 Stat. 1739 (1970).

3

National Highway Traffic Safety Administration. Uniform Guidelines for State Highway 

Safety Programs. Highway Safety Program Guideline No.1: Periodic Motor Vehicle 

Inspection, DOT HS 812 007A (April 2014). 

4

At the time of the request, Senator McCaskill was the Chair of the Senate Subcommittee 

on Consumer Protection, Product Safety, and Insurance.

Letter
Page 2 GAO-15-705 Vehicle Safety Inspections

assesses: 1) what is known about the safety benefits and costs of 

operating state vehicle safety inspection programs, 2) any challenges that 

states have faced in operating these programs, and 3) any actions 

NHTSA could take to assist states with these programs.

For this assessment, we conducted a literature search for studies that 

analyzed relationships between safety inspections and outcomes, such 

as crash rates, vehicle component failure, and a vehicle fleet’s age. We 

limited our literature search to articles and reports published after 1990—

the last time that GAO conducted a comprehensive literature review on 

this topic.5 We identified six studies published from 1992 through 2013 

that were relevant to the research objective on the safety benefits and 

costs of operating state vehicle safety inspection programs and four 

studies relevant to the research objective on challenges that states face 

that were sufficiently reliable for the purposes of this report. We analyzed 

data for crashes related to vehicle component failure in two states before 

and after program elimination in each of those states and analyzed 

national data for crash trends related to vehicle component failure using 

data for 2009—2013 from NHTSA’s National Automotive Sampling 

System General Estimates System (NASS-GES). For each of the data 

sets, we analyzed the data for possible errors, interviewed relevant 

officials, and determined the data were sufficiently reliable for the 

purposes of this report. We reviewed federal and state policy and 

program documents related to inspection programs. We also reviewed 

federal and state statutes, regulations, and guidelines. We reviewed 

Executive Order 13563 on Improving Regulation and Regulatory Review, 

which provides principles that agencies should follow in establishing 

regulations.6 We compared these documents to NHTSA’s actions related 

to state vehicle safety inspection programs. We conducted interviews with 

officials in 15 of the 16 states that currently have a safety inspection 

program using a structured set of interview questions.7

 5

GAO, Motor Vehicle Safety: NHTSA Should Resume Its Support of State Periodic 

Inspection Programs, 

We also 

interviewed officials in five of six jurisdictions (four states and Washington 

DC) that eliminated their state vehicle safety inspection program since 

GAO/RCED-90-175 (Washington, D.C.: July 5, 1990).

6

Exec. Order. No.13563, 76 Fed. Reg. 3821 (Jan. 21, 2011).

7

New Hampshire was the only state currently operating a vehicle safety inspection 

program that did not respond to our request for an interview. 
Page 3 GAO-15-705 Vehicle Safety Inspections

1990,8

We conducted this performance audit from November 2014 through 

August 2015 in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to 

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on our audit objectives. We believe 

that the evidence obtained provides a reasonable basis for our findings 

and conclusions based on our audit objectives.

NHTSA officials, and representatives from safety groups and 

automotive industry groups. Some states require vehicle inspections that 

do not fall under the periodic motor vehicle inspection guideline and are 

therefore not reviewed in this report. For example, states may have 

required emissions inspections or safety inspections for specific types of 

vehicles, such as vehicles for-hire, commercial vehicles, and school 

buses. In some states emissions testing and safety inspections are 

administered as one inspection program; when this approach is the case, 

emissions information was incidentally reviewed and noted in this report. 

See appendix I for more information on our scope and methodology. See 

appendix II for a list of all of the states that have had a vehicle safety 

inspection program.

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:

• 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

• providing guidance and other assistance to states to help address 

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, 

 8

Jurisdictions we spoke with and the year they eliminated their programs: Arkansas 

(1998), Oklahoma (2001), District of Columbia (2009), New Jersey (2010), and Mississippi 

(2015). South Carolina eliminated its program in 1995 and did not have knowledgeable 

program officials to speak with us. 

Background
Page 4 GAO-15-705 Vehicle Safety Inspections

and if a state failed to implement these standards, DOT could withhold a 

percentage of federal-aid highway funds apportioned to the state.9 As 

shown in figure 1, this authority changed in 1976 when legislation limited 

NHTSA’s authority to withhold apportioned funds.10

Figure 1: History Timeline for State Vehicle Safety Inspection Programs

Since that change, 

states have been able to choose whether or not to follow the guidelines in 

developing their highway safety programs.

a

Highway Safety Act of 1987, Pub, L, No.100-17, Title II, §206,101 Stat.132, 221 (1987).

b

National Highway Traffic Safety Administration. Study of the Effectiveness of State Motor Vehicle 

Inspection Programs. Final Report. August 1989.

c

GAO, Motor Vehicle Safety: NHTSA Should Resume Its Support of State Periodic Inspection 

Programs, GAO/RCED-90-175 (Washington, D.C.: July 5, 1990).

 9

The Highway Safety Act of 1966, Pub. L. No. 89-564, title I, § 402, 80 Stat. 731 (1966) 

required each state to have a highway safety program in accordance with standards 

promulgated by DOT and authorized DOT to reduce, by 10 percent, the apportionment of 

any authorized federal-aid highway funds to be distributed to any state not implementing a 

highway safety program, unless determined by the Secretary of Transportation that it was 

not in the public interest,

10Pub. L. No. 94-280 § 208 (1976). 
Page 5 GAO-15-705 Vehicle Safety Inspections

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.11

 11We did not actively collect information on emissions inspection because it is regulated 

by the Environmental Protection Agency in the Department of Energy and does not 

directly relate to a vehicle safety inspection other than the cases where states require

vehicle owners to conduct both inspections at the same time. 
Page 6 GAO-15-705 Vehicle Safety Inspections

Figure 2: States with Vehicle Safety Inspection Programs, July 2015

a

Fees are paid by the consumer at the time of inspection.

b

Annual in areas where emissions inspections are required; biennial in all other areas.

c

Random roadside inspections.

d

4 years after the model year, 8 years after the model year, 10 years after the model year, and 

annually after that.

e

Includes emissions inspection.

f

Market-driven.

g

Fee for modified vehicles.
Page 7 GAO-15-705 Vehicle Safety 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 

inspection program; it is typically a market-driven process.12

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.

However, 

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).

13 NHTSA has developed 

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.

 12Some safety inspection programs are combined with emissions programs and emissions 

program contracts may limit the number of private inspection stations a state may have, 

thus limiting the number of private safety inspection stations.

1349 C.F.R. Part 570 – Vehicle In Use Inspection Standards. 
Page 8 GAO-15-705 Vehicle Safety Inspections

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;14

 14According to Utah state officials this includes glass that is broken, missing, shattered, or 

jagged, and also includes issues with tinting, wipers/washer, and mirrors. 

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.

Impact of Safety 

Inspections on 

Vehicle Safety Is 

Unclear as Benefits 

and Costs Are Difficult 

to Quantify

Officials in States with 

Vehicle Safety Inspection 

Programs Said Their 

Programs Enhance 

Vehicle Safety
Page 9 GAO-15-705 Vehicle Safety Inspections

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.15

 15We reviewed 29 studies, including peer-reviewed articles, government publications, and 

trade publications. Of these studies, we determined the methodology and findings for 6 

studies—published from 1992 through 2013—were reliable enough to include for the 

purposes of our report. 

Since GAO last conducted a review 

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 

Research Examining 

Effect on Crash Rates is 

Inconclusive, in Part Due 

to Limited Data
Page 10 GAO-15-705 Vehicle Safety Inspections

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.16

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 policereported 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.

See appendix III for more 

information on each of the studies.

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.

 16M. D. Keall, S. Newstead. “An evaluation of costs and benefits of a vehicle periodic 

inspection scheme with six-monthly inspections compared to annual inspections.” 

Accident Analysis & Prevention, 58 (2013): 81-87.
Page 11 GAO-15-705 Vehicle Safety Inspections

Figure 3: Estimated Number of Crashes Related to Vehicle Component Failure, 

2009—2013

Note: The numbers presented in the graphic are the 95% confidence interval estimate rounded to the 

nearest 10 crashes. Numbers may not add due to rounding. For the upper and lower bound estimates 

see appendix IV.

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.17

 17We attempted to gather data for 5 years before and after the year of the program was 

eliminated for each state. South Carolina, (eliminated in 1995) could only provide crash 

data back to 2001; Arkansas (eliminated in 1993) could only provide data back to 1999; 

and, Washington D.C. (eliminated 2009) could only provide 2014 data. 

In both cases, crashes involving 

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 
Page 12 GAO-15-705 Vehicle Safety Inspections

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.18

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 

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.

 18NHTSA. National Motor Vehicle Crash Causation Survey: Report to Congress, DOT HS 

811 059 (July 2008).

States Generally Do Not 

Directly Track Costs of 

Operating Safety 

Inspection Programs
Page 13 GAO-15-705 Vehicle Safety Inspections

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 

State Challenges 

Include Oversight and 

Paper-Based Data 

Systems
Page 14 GAO-15-705 Vehicle Safety Inspections

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 dataentry 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 
Page 15 GAO-15-705 Vehicle Safety Inspections

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.19 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.20

Some states have taken action to address their challenges, including 

implementing more stringent program rules, preparing manpower studies, 

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.

 19David Merrell, Marc Poitras, and Daniel Sutter, “The Effectiveness of Vehicle Safety 

Inspections: An Analysis Using Panel Data,” Southern Economic Journal, vol. 65, no. 3, 

(1999): 571-583.

20North Carolina General Assembly Program Evaluation Division. Doubtful Return on the 

Public’s $141 Million Investment in Poorly Managed Vehicle Inspection Programs – Final 

Report to the Joint Legislative Program Evaluation Oversight Committee, Report No. 

2008-12-06 (2008).
Page 16 GAO-15-705 Vehicle Safety Inspections

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.21

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:

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.

• 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 

 21A state official told us that the fingerprint scanning only applies to safety inspections 

performed on passenger vehicles that require an emissions test. 
Page 17 GAO-15-705 Vehicle Safety Inspections

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.

Figure 4: Diagram of a Light-Emitting Diode (LED) light.

NHTSA Could 

Improve 

Communications with 

States
Page 18 GAO-15-705 Vehicle Safety Inspections

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).22

Officials in the state that has considered but not specifically addressed 

LED brake lights in the inspection program said they tried to contact 

NHTSA for guidance, but found it difficult to locate a NHTSA official to 

answer their question and did not receive a clear answer. NHTSA officials 

told us that they respond to inquiries and have provided guidance to state 

and local law enforcement officials. NHTSA’s lighting standard sets a 

minimum luminosity for vehicle lights, but does not directly address LED 

lights, and NHTSA officials reiterated that they do not have information on 

how many diodes on a given light can fail before it no longer meets the 

federal standard.23

 22Officials in two states also told us that they did not need to specifically address LED 

lights in their inspections because the state’s current standard is based on visibility from a 

specific distance. Officials in the remaining 3 states did not provide information on how 

they inspect LED brake lights. 

NHTSA officials also said that since lights vary 

depending on the manufacturer only the manufacturer would know how 

much, if any, buffer is built into an LED light. NHTSA officials explained 

that manufacturers have flexibility in designing their lights, as long as the 

lights meet the minimum luminosity standard; therefore, they could not 

provide states with a specific number of LED lights that could malfunction 

for a given vehicle. One state official we spoke with said that it would 

require too many resources to contact all the different manufacturers to 

seek guidance on LED lights. While NHTSA may not directly address 

LED lights in the lighting standard at this time, there may be other 

information NHTSA could provide to states concerning LED brake lights if 

there were a designated communication channel for states to bring these 

kinds of issues to NHTSA’s attention. For example, if found appropriate, 

23Federal Motor Vehicle Safety Standard No. 108: Lamps, reflective devices, and 

associated equipment, 49 C.F.R. § 571.108. 
Page 19 GAO-15-705 Vehicle Safety Inspections

NHTSA could sponsor research in the area of LED brake lighting as it has 

done in the past that might be helpful to states.24

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.25

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).

However, 

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.

26

 24NHTSA has sponsored research in the area of LED lighting. For example, Walter W.

Wierwille, Robert E. Llaneras, and Lucas M. Neurauter, Evaluation of Enhanced Brake 

Lights Using Surrogate Safety Metrics: Task 1 Report: Further Characterization and 

Development of Rear Brake Light Signals. (Report No. DOT HS 811 127 National 

Highway Traffic Safety Administration, Washington, D.C.: April 2009) and N. K. Greenwell, 

Effectiveness of LED Stop Lamps for Reducing Rear-End Crashes: Analyses of State 

Crash Data. (Report No. DOT HS 811 712 National Highway Traffic Safety 

Administration, Washington, D.C.: February 2013).

Specifically, these states 

would like guidance on whether they should check to see that these 

technologies are functioning correctly for vehicles that were manufactured 

25GAO. Intelligent Transportation Systems: Vehicle-to-Vehicle Technologies Expected to 

Offer Safety Benefits, but a Variety of Deployment Challenges Exist, GAO-14-13 

(Washington, D.C.: November 2013).

26Federal Motor Vehicle Safety Standard No. 138: Tire pressure monitoring systems, 49 

C.F.R. § 571.138, was implemented in 2009, and the revision to the Federal Motor Vehicle 

Safety Standard No. 111: Rear visibility, 49 C.F.R. § 571.111, was implemented in 2014.
Page 20 GAO-15-705 Vehicle Safety Inspections

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 coldweather 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.27

 27National Highway Traffic Safety Administration. NHTSA Safety Advisory: Preventing 

Brake Pipe Failures Due to Corrosion (Apr. 9, 2015.)

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.
Page 21 GAO-15-705 Vehicle Safety Inspections

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 1356328

 2876 Fed. Reg. 3821.

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.
Page 22 GAO-15-705 Vehicle Safety Inspections

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.

Conclusions

Recommendation

Agency Comments 

and our Response
Page 23 GAO-15-705 Vehicle Safety Inspections

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.

Sincerely yours,

Susan Fleming

Director, Physical Infrastructure Issues
Appendix I: Objectives, Scope, and 

Methodology

Page 24 GAO-15-705 Vehicle Safety Inspections

We conducted a review of state motor vehicle inspection programs and 

National Highway Traffic Safety Administration’s role in assisting these 

programs.1

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.

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.

 1

Some states have inspections that do not fall under the periodic motor vehicle inspection 

guideline reviewed in this report. For example, states require safety inspections at the time 

of registration or for specific types of vehicles, such as vehicles for-hire, commercial 

vehicles and school buses, but since these inspection programs are not applied 

periodically and to all registered motor vehicles they do not fall under the periodic motor 

vehicle inspection guideline. Some states have required emissions testing, which are also 

not covered in this report. However, in some states emissions testing and safety 

inspections are administered as one inspection program; when this is the case emissions 

information was incidentally reviewed and noted in this report.

Appendix I: Objectives, Scope, and 

Methodology
Appendix I: Objectives, Scope, and 

Methodology

Page 25 GAO-15-705 Vehicle Safety Inspections

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 
Appendix I: Objectives, Scope, and 

Methodology

Page 26 GAO-15-705 Vehicle Safety Inspections

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).
Appendix II: List of States that Have Required 

Vehicle Safety Inspections, 

1929-2015

Page 27 GAO-15-705 Vehicle Safety Inspections

States Currently Requiring Annual Safety 

Inspections States that Repealed Inspection Programs

State Started State Started Ended

Pennsylvania 1929 Colorado 1937 1981

Maine 1930 New Jersey 1938 2010

Massachusetts 1930 District of Columbia 1939 2009

New Hampshire 1931 New Mexico 1953 1977

Virginia 1932 Mississippi 1961 2015

Delaware 1933 Georgia 1965 1982

Utah 1936 Wyoming 1967 1977

Vermont 1936 Florida 1968 1981

Texas 1951 Idaho 1968 1976

West Virginia 1955 Kentucky 1968 1978

New York 1957 South Carolina 1968 1995

Rhode Island 1959 South Dakota 1968 1979

Louisiana 1961 Arkansas 1969 1998

Hawaii 1961 Indiana 1969 1980

North Carolina 1966 Nebraska 1969 1982

Missouri 1969 Oklahoma 1969 2001

Source: GAO and GAO-90-175 App. I for initial start dates of the vehicle safety inspection program and for all repealed safety inspection date prior to 1991. | GAO-15-705

Appendix II: List of States that Have 

Required Vehicle Safety Inspections, 

1929-2015
Appendix III: Studies Reviewed that Examine 

Vehicle Inspections and Crash Rates

Page 28 GAO-15-705 Vehicle Safety Inspections

Article Methodology Conclusions

U.S. studies Sutter, David and Poitras, Marc 

(2002). The Political Economy of 

Automobile Safety Inspections. 

Public Choice, 133 (3-4), 367-387.

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.

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.

International 

Studies

Keall, M. D., & Newstead, S. 

(2013). An evaluation of costs and 

benefits of a vehicle periodic 

inspection scheme with sixmonthly 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.

Source: GAO Analysis of Articles. | GAO-15-705

Appendix III: Studies Reviewed that Examine 

Vehicle Inspections and Crash Rates
Appendix IV: Estimated Number of Crashes 

Listed with Vehicle Component Failure 2009-

2013 with Lower and Upper Bound 95% 

Confidence Intervals (CI)

Page 29 GAO-15-705 Vehicle Safety Inspections

Year

Vehicle 

Factor

Estimated Crashes Listed 

with Vehicle Component 

Failure

Lower Bound 

95% CI

Upper Bound 

95% CI

2013

Total 124,530 108,960 140,100

Tires 48,140 39,550 56,730

Brakes 34,730 28,050 41,420

Steering 10,050 6,190 13,910

Other 31,610 24,920 38,300

2012

Total 118,000 99,640 136,360

Tires 43,280 35,380 51,180

Brakes 34,360 27,800 40,930

Steering 10,510 7,870 13,140

Other 29,850 23,990 35,710

2011

Total 110,000 93,410 126,590

Tires 38,340 31,350 45,340

Brakes 32,210 26,180 38,250

Steering 8,400 6,160 10,630

Other 31,050 25,020 37,080

2010

Total 103,000 87,710 118,290

Tires 39,210 32,060 46,350

Brakes 25,900 20,590 31,220

Steering 7,890 5,560 10,2210

Other 30,000 24,120 35,880

2009

Total 112,000 93,930 130,070

Tires 38,270 30,500 46,030

Brakes 33,670 26,630 40,710

Steering 8,710 6,020 11,390

Other 31,360 24,680 38,040

Source: GAO Analysis of the National Highway Traffic Safety Administration National Automotive Sampling Generalized Estimate 

System. | GAO-15-705

Note: The numbers presented are the 95% confidence interval estimate as well as the upper and 

lower bound estimates, all numbers are rounded to the nearest 10 crashes. Numbers may not add as 

a result of rounding.

Appendix IV: Estimated Number of Crashes 

Listed with Vehicle Component Failure 2009-

2013 with Lower and Upper Bound 95% 

Confidence Intervals (CI)
Appendix V: Comments from the Department 

of Transportation

Page 30 GAO-15-705 Vehicle Safety Inspections

Appendix V: Comments from the Department 

of Transportation
Appendix VI: GAO Contacts and Staff 

Acknowledgements

Page 31 GAO-15-705 Vehicle Safety Inspections

Susan Fleming, (202) 512-2834 or Flemings@gao.gov

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.

Appendix VI: GAO Contacts and Staff 

Acknowledgements

GAO Contact

Staff 

Acknowledgements

(541125)
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