The US: state inspections, emissions tests and tread law

A car can go its whole life in some US states without a stranger ever looking at its brakes. Drive the same car across a state line and it may need a sticker on the windscreen (windshield) every year, the state's proof that it passed, a check of its tread down to the thirty-second of an inch (under a millimetre), and a look under the bonnet (hood) for a missing catalytic converter. Great Britain has one test for the whole country, which lesson 21, "The MOT and Northern Ireland's vehicle test", covered. The US has no national test at all. It has states, and they don't agree. Five of them show the range here, and they lead to a real disagreement: whether periodic safety inspection prevents crashes.

This is general information, not legal advice. The rules differ between England and Wales, Scotland, Northern Ireland and each US state, and they change. Every state rule, fee and date below is as read on 26 September 2026, and each one names its state. None of them is "US law" unless it says federal.

No national test: the shape, and why it shrank

This is general information, not legal advice.

The main official account this course found is a 2015 report by the Government Accountability Office (GAO), the audit office of the US Congress. It counted the states: "As of July 2015, we found 16 states with periodic inspection programs." Of those, "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."¹ That's the most recent official national count this course found. It's eleven years old, and at least one state has left the list since: Texas ended safety inspection for non-commercial vehicles from 1 January 2025, as below. Whether any other state has started or stopped since 2015, this course didn't check, so it gives no current total.

Why did the number fall? GAO ties the long decline to federal money. From 1967, the Department of Transportation "could withhold a percentage of federal-aid highway funds apportioned to a state that did not implement a periodic motor vehicle inspection program". Then: "Since 1976, after legislation limited NHTSA’s authority to withhold federal-aid highway funding, the number of states with programs has declined."¹ Since that change, in GAO's words, "states have been able to choose whether or not to follow the guidelines". NHTSA's guideline, still recommending periodic inspection of all registered vehicles, remained as of GAO's report.¹ Of the five states and the District of Columbia that dropped programmes between 1990 and 2015, GAO says they did so "some citing a lack of evidence proving the program’s effectiveness or saving financial resources as reasons".¹

Two things are easy to confuse with the safety test: emissions testing, a separate programme under the federal Clean Air Act, and tread rules, where the only federal rule that binds a driver covers commercial vehicles. Each has its own section below.

Five states, side by side

This is general information, not legal advice.

These five were chosen because between them they show the range: annual safety with emissions in some counties (a county is a local area within a state), annual safety with emissions everywhere, annual safety with emissions only in places the state's law names, no safety test since 2025, and emissions only. They aren't a sample of the country. Your state may do something none of them does. A US car is registered with its state, which renews the registration at intervals it sets, and a state can make renewal wait on a passed test, as New York and California do below.

Pennsylvania. PennDOT, the state transport department, runs its programme through "official PennDOT Inspection Stations (usually a repair garage or a service station with a repair shop)", and "Inspection fees are posted at official inspection stations."² Its regulations are published as Pub 45, which is 67 Pa. Code Chapter 175; the edition read is dated February 2026.³

New York. The state's Department of Motor Vehicles (DMV), the office that registers cars, runs one visit for both tests: "The emissions inspection is done at the same time as the annual safety inspection." Two consumer points on its page are New York's rules, and worth asking about wherever you're inspected: "The inspection station must have your permission before beginning any repairs", and "You are not required to have your vehicle repaired or re-inspected at the station that performed the initial inspection."⁴

Virginia. The State Police run it. Its published inspection procedure runs from brakes and lights to the hood latch, fluid levels ("Brake fluid" and "Power steering fluid"), the airbag and its readiness light, and the emissions parts: "No parts removed, disconnected, or rendered inoperable."⁵ The emissions test itself is set by statute: § 46.2-1178 of the Code of Virginia applies it in localities it names: five counties and five cities in one subsection, and six more in another, subject to regulations and EPA approval. Blacksburg, the case below, is in none of them.[17]

Texas. The Department of Public Safety (DPS) announced the change in January 2025: "as of Jan. 1, 2025, non-commercial vehicles no longer need a vehicle safety inspection prior to registration." It is "due to House Bill 3297", passed by the 88th Legislature in 2023. Emissions tests continue in the counties it names, and "All commercial vehicles in all counties are still required to obtain a passing vehicle safety inspection."⁷

California. The state programme this course read for California is Smog Check, run by the Bureau of Automotive Repair (BAR), and it tests emissions. "Inspection prices are not regulated by BAR."⁸ GAO's 2015 appendix lists neither California among the states then inspecting nor among those that had repealed a programme.¹ This course found no California page that says in words that there's no periodic safety inspection.

A car in Blacksburg, Virginia

This is general information, not legal advice.

A car registered in Blacksburg, Virginia, goes in for its annual inspection. Three things from the state's manual and pages decide what happens.

The fee first. Virginia's regulation 19VAC30-70-40 sets maximums: "$20 for each inspection of any other vehicle, including trailers and motor homes", which covers a car.⁶ That's a ceiling, not a price, the same shape as Great Britain's MOT maximum in lesson 21.

The tyres (tires) next. Lesson 8, "Tyres II: tread, damage, age, and when to replace", walked through Virginia's measuring method on a tyre in Lynchburg, and it applies here unchanged: two adjacent grooves where the tread is thinnest, more measurements only if both are under 2/32 inch, and "Do not take measurements from the tread wear indicators."⁶ One line in the same regulation catches people out. The inspector rejects the car if it "has installed on any axle a space saver emergency spare tire that is intended for temporary use".⁶ The owner who put the compact spare on after a puncture last month, and never swapped it back, fails on that alone.

Then what a fail means. The State Police page: "ALL DEFECTS MUST BE CORRECTED AND THE VEHICLE REINSPECTED WITHIN 15 DAYS. THE DRIVER MAY BE SUBJECT TO RECEIVING A TRAFFIC SUMMONS FOR ANY DEFECT STILL PRESENT WHEN THE VEHICLE IS OPERATED ON THE HIGHWAY."⁵ Its FAQ adds that a rejection sticker "in itself, places no travel restrictions on the vehicle; however, it does not provide any exception to any statute governing equipment defects."⁵ So fifteen days to fix it isn't fifteen days of permission to drive a defect.

Replacing the spare is Yours, on conditions: the conditions are lesson 19's, "Changing a wheel safely", and, as lesson 19 reads its sources, it's never on a motorway, a US freeway shoulder or any other fast road, where the callout's steps apply instead. Repairing the punctured tyre is Call someone, a tyre fitter's job, as lesson 18, "A flat tyre: the decision, and spare, space saver, sealant or run-flat", says.

From Waco, Texas, to Schenectady, New York

This is general information, not legal advice.

Now the wrinkle. A privately owned 2019 petrol (gasoline) car has been registered in Waco, Texas, since 2022. Waco is in McLennan County, which isn't on DPS's list of emissions counties, so since 1 January 2025 the car has had no inspection of any kind.⁷ In 2026 its owner moves to Schenectady, New York, and registers it there.

Two lines on the New York DMV's page decide it. "If your vehicle was registered in another state which issues an inspection sticker, you do not need to have your vehicle inspected immediately. Your out-of-state inspection remains valid until it expires or for one year after the registration date, whichever comes first." And: "If the previous inspection was performed in a jurisdiction that does not issue an inspection sticker, you must have your vehicle inspected in New York."⁹

The point of the case is that nothing about the car changed at the state line. What changed is which state's rule it lives under.

Emissions testing: a separate programme

This is general information, not legal advice.

The emissions test has a different origin from the safety test. The Environmental Protection Agency (EPA): "The 1990 Amendments to the Clean Air Act established I/M requirements for several areas across the country."¹⁰ I/M stands for inspection and maintenance, which EPA defines as "the periodic inspection of the emissions control systems of motor vehicles". The programmes are required mainly where air quality falls short of the national standards, and "States are responsible for developing their own I/M program".¹¹ On this course's reading, that fits Texas, where DPS says "Emissions tests are required in major metropolitan areas" and Waco's county isn't on its list,⁷ and it's why New York's DMV says "The 1990 Federal Clean Air Act requires New York State to conduct an inspection program".⁴

EPA names three kinds of test. Visual inspections "deter tampering by checking for the presence of certain required emission control parts (e.g., catalytic converter replaced with a straight pipe)." Tailpipe testing is mainly "for vehicles that are model year 1995 and older". And the one most cars now get: "Beginning with the 1996 model year, vehicles have been equipped with OBD computerized systems. The OBD system continuously monitors the emission control systems and will activate the ‘‘Check Engine’’ light on the dashboard if a fault, also known as a Diagnostic Trouble Code (DTC), is detected".¹¹ Lesson 11 explained the light; this is where the state's test meets it.

California shows the emissions test standing on its own. BAR: "A Smog Check is required every other year to renew your vehicle registration", for petrol, hybrid and alternative-fuel cars of model year 1976 and newer and diesels of 1998 and newer (the model year is the one the maker gives the car's model), and also on a change of ownership and on first registering a car in California. Petrol, hybrid and alternative-fuel cars "eight model years and newer" are exempt at renewal and pay a smog abatement fee instead. At a change of ownership the exemption is "four model years and newer", with a smog transfer fee instead. Electric vehicles don't need one.⁸ And BAR ties it to lesson 11: "A vehicle will not pass a Smog Check with the check engine light on."⁸

Removed parts: what three states check

The federal rule is in the Clean Air Act at 42 U.S.C. 7522(a)(3), which lesson 3, "Diesel exhaust: the DPF and AdBlue", quoted: it prohibits any person "knowingly to remove or render inoperative" an emission-control device after the car is sold.¹² Three of the states read here check for it at inspection, and two of them in the safety inspection. Pennsylvania's regulation, in the 42 counties with no emissions test, rejects a car if "The catalytic converter has been removed, disconnected or is the wrong type for the certified vehicle configuration", with the same test for five other parts, "Provided that the make and model year of the vehicle would have originally been equipped with the device".³ Virginia's list says "No parts removed, disconnected, or rendered inoperable", adding "This includes the catalytic converter and the fuel tank filler pipe".⁵ California's BAR says modified or non-approved software "will cause a vehicle to fail a Smog Check".⁸ A "delete" (lesson 3's word for an emissions part removed or switched off) is not a maintenance choice anywhere this course read.

A car in Clearfield, Pennsylvania

A car in Clearfield, Pennsylvania, has had its catalytic converter cut out and replaced with a straight pipe. Clearfield County is one of the 42 on the state environmental department's Drive Clean PA page where cars need no emissions test, though most "are required to pass a visual anti-tampering check as part of a safety inspection".[16] So the safety inspection is where it's caught, and § 175.80(d) rejects the car.³ In a county that does test emissions, that test does the checking instead; this course didn't read Pennsylvania's emissions test rules, so it says no more. Putting the converter back is Call someone.

Tread law, gathered

This is general information, not legal advice.

Lesson 8 set out the tread rules; this section gathers them. The federal figures in 49 CFR 393.75 are for commercial motor vehicles, and they're the only federal tread rule this course found that binds a driver. For passenger cars, 49 CFR Part 570 sets "not less than two thirty-seconds of an inch" as a criterion "for the inspection of motor vehicles by State inspection systems", and says the part "does not in itself impose requirements on any person".[18] GAO says the same: these standards "apply to all states that choose to implement a vehicle safety inspection program".¹ So for driving a private car, tread law is set by states. The three inspection states read all use 2/32 of an inch at inspection, each measured its own way: Pennsylvania at any one point, New York in the grooves "showing the most wear", Virginia at the thinnest spot, and at two more points only if that one is under.³⁴⁶

NHTSA's advice, for any car in the US, is to replace tyres worn to 2/32 of an inch. That's advice, not law; lesson 8 quotes it with its source, and the argument about replacing earlier.

Between inspections: whose duty?

This is general information, not legal advice.

In Great Britain, lesson 20, "The law on a car's condition: Great Britain and Northern Ireland", showed a driver's duty that applies every time the car is used, in the Road Traffic Act. Apart from one Texas statute, below, this course read no US statute that does the same, and it doesn't borrow Great Britain's. What it read first is what three state agencies say on their own pages.

New York's DMV: "Motor vehicles are required by law to be in safe operating condition whenever they are driven on a public street or roadway in New York State."⁴ Virginia's State Police, above: a rejection sticker "does not provide any exception to any statute governing equipment defects".⁵ And Texas's DPS, in the same release that announced the end of inspection: "Regular maintenance ensures the proper operation of your vehicle’s headlights, taillights, horn, mirrors, windshield wipers, tires and other critical functions. Driving a vehicle without many of these properly working safety features is against the law and puts everyone at risk."⁷

Those are each agency's statements about its own state's law. For Texas this course read the law too. The same bill that ended the test, House Bill 3297, removed one offence from 1 January 2025: driving a vehicle "in a mechanical condition that endangers a person, including the operator or an occupant, or property" (Transportation Code § 548.604).[19] It left another. Section 547.004 makes it a misdemeanor to operate or move a vehicle that "is unsafe so as to endanger a person" or isn't equipped as that chapter requires.[20] On this course's reading, Texas removed a test and one of two overlapping offences, and kept the offence of driving a car that is unsafe. The New York and Virginia statutes behind their agencies' words weren't read.

The checks are Yours in every state: lessons 7 to 10 gave them. An inspection, where there is one, is a snapshot, just as lesson 21 said of the MOT.

Does periodic safety inspection reduce crashes?

Everything so far is established: each state's rule says what it says. This question is different. It's a contested empirical question: serious, informed people disagree, and the evidence doesn't settle it. Behind it sits a value question too, about how much cost and inconvenience a possible safety gain is worth, and that one is for each state's voters and legislators. This course answers neither. It gives the evidence it read, then each side in its own words, with who is speaking. Logic and Argument lesson 7, "Reconstruction and charity: the strongest version first", is the rule for reading both.

The evidence GAO read

GAO reviewed 29 studies and judged six reliable enough to use.¹ Its summary: "research remains inconclusive about the effect of safety inspection programs on crash rates." Of the three US studies, "none were able to establish a statistically significant effect of safety inspection programs on crashes involving either fatalities or injuries."¹ Abroad, two Norwegian studies found that inspection improved the technical condition of cars but not their crash rates, and a New Zealand study found that going from yearly to six-monthly inspection might cut crashes by about 8 per cent, with a confidence interval from 0.4 to 15 per cent that GAO says "indicated considerable statistical uncertainty".¹ GAO also compared crash rates before and after two states, New Jersey and Oklahoma, dropped inspection, and found the rate "did not significantly change for either state", adding that "this analysis does not provide sufficient evidence to conclude that inspection programs did not have an effect on crash rates".¹

And then the sentence that stops the evidence being read as a verdict: "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."¹

Why is it so hard to tell? GAO gives the reasons. Vehicle component failure, on estimates from NHTSA data, is "a factor in about 2 to 7 percent of crashes", so any effect is a small signal in a big number. There is "no comprehensive database for all police reported crashes in the United States"; the national sample "is not set up to be representative at the state level"; and, as some literature and safety advocate organisations told GAO, police officers "often do not have the time and resources to conduct a thorough vehicle check".¹ In the police-reported sample, GAO found component failure noted in around 2 per cent of crashes from 2009 to 2013. When NHTSA's investigators examined cars thoroughly, in a 2005 to 2007 survey of over 5,000 crashes, component failures "were found to be present in 6.8% of crashes", present rather than proved to be the cause. GAO reads that as a sign the police reports undercount.¹

GAO also reports what running a programme is hard about. Eleven of the 15 inspecting states named oversight, including making sure stations "do not intentionally pass vehicles that should have failed", and one 2008 state study found inspections averaging 5 minutes against the 15 to 30 a thorough one should take. Some states have responded, GAO says, by "implementing more stringent program rules", and one now makes mechanics use fingerprint scanners before some inspections.¹

The case for keeping inspection, in its holders' own words

PennDOT, which runs Pennsylvania's programme, states the purpose on its own page: "Pennsylvania requires vehicle safety inspections to ensure that vehicles are maintained for safe operation. Safety Inspections can prevent vehicle failure on the highways and crashes that may result in injuries or death."² New York's DMV puts it as a minimum standard: its programme "helps make sure every vehicle registered in this state meets the minimum standards for safe operation on public streets and highways."⁴

The fullest statement of the case is the officials GAO interviewed in 15 inspecting states, as GAO reports them. They "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." Their evidence is what inspections find. "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's officials "believed that their state’s roadways were safer" because their programme found safety problems in over 1.4 million of the state's 7.5 million vehicles in 2014, which GAO puts at 19 per cent, and 700,000 of them were rejected for brakes.¹ And they argued the need is growing: Rhode Island's officials said road salt corrodes brake lines and steering, and "vehicles are staying in service longer"; GAO adds DOT figures showing the average passenger car's age rising from 8.4 years in 1995 to 11.4 in 2013.¹ Behind them stands the federal guideline, which, as GAO reported it, recommends periodic inspection "to reduce the number of vehicles with existing or potential conditions that may contribute to crashes".¹

Who is speaking matters. These are the agencies that run the programmes. In Texas, the groups on record against House Bill 3297 included an inspection company, an inspection station and the Texas State Inspection Association, whose business is inspection, and also police chiefs' and sheriffs' associations, a police officers' union, and carmakers' and dealers' representatives, as the House Research Organization's digest lists them.¹³ The digest lists names, not arguments; this course read no statement of their reasons.

The case for ending it, in its holders' own words

The Texas House committee's analysis of House Bill 3297 gives the reason for the bill in one line: "The impact of the mandatory vehicle safety inspection program on road safety is not strong enough to justify the program's existence."¹⁴ The author's and sponsor's statement of intent, as the Texas Senate Research Center recorded it, makes the fuller case: "Vehicle inspections are costly, time-consuming, and often provide little benefit to public safety. The process requires Texans to take time off work or out of their busy schedules to have their vehicles inspected at a designated location. This can be especially difficult for those living in rural areas, where inspection stations may be few and far between." It argues the test checks the wrong things: "Many of the items checked during an inspection are not related to safety. For example, inspectors often check the tint on windows and the condition of license plates, which have no bearing on whether a vehicle is safe to drive." It adds that they "do little to improve road safety and serve only to generate revenue for the state". And it argues the car now checks itself: "Modern vehicles are equipped with onboard diagnostic systems that constantly monitor their performance and can detect any potential issues."¹⁵

GAO reports the same reasons from states that ended programmes earlier. "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 2010 New Jersey's Motor Vehicle Commission chief "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".¹

Who is speaking, once. These are legislators and the states that chose to repeal. In Texas, those on record in favour of the bill included the Texas Public Policy Foundation and the Texas Conservative Coalition Research Institute, two policy research organisations; the True Texas Project, a political group that began as a tea party; a county tax assessor-collector; an electric-car maker; and a recreational-vehicle trade association, among others, as the digest lists them.¹³ Again, names only.

Weighing one claim from each side

Take one claim from each case and ask the same three questions: what kind of claim is it, what does it rest on, and what would test it?

Start with Pennsylvania's figure: more than 529,000 cars failed and were repaired in a year. It's a count of defects found and fixed, and it rests on the state's own inspection records. It shows the inspection does something to cars. It doesn't, by itself, show fewer crashes, because it can't tell which of those defects would have caused one, or whether owners would have fixed them anyway. What would test it is whether states like Pennsylvania have fewer component-failure crashes than comparable states without inspection, other differences controlled for, and that is exactly the evidence GAO found missing.

Where they meet, and what would settle it

On this course's reading, neither side disputes that a car with failed brakes or bald tyres is dangerous, and neither, in the words quoted, cites a US study showing that inspection cuts crashes. They disagree about what that absence means. GAO reads it partly as a problem of data; the case for rests instead on what inspections find, and the case against reads it as a reason not to make every owner pay. And they weigh the cost differently, which is the value half of the question.

Each side has a stake. The agencies that run inspections, and the businesses paid to do them, gain from keeping them; the owners who pay for inspections gain from ending them (an Oklahoma Senate press release put the saving there at $12 million), and the legislators who proposed repeal answer to those owners as voters. An interest is a reason to check the evidence harder, not a reason to call the claim false, and that applies to both sides equally.

Between the two, GAO reports states that kept their programmes by narrowing them: officials in two "either relaxed or eliminated some non-safety related standards" or "exempted newer-model vehicles from safety inspections as a compromise with state legislatures to continue their programs".¹

What would settle it, from GAO's own account of the gaps: crash data that records component failure reliably, from thorough vehicle examinations rather than roadside police reports, and that is representative state by state, so that states with and without inspection, or one state before and after a change, can be compared with other causes of crashes controlled for. And for the cost half, what a programme costs to run, which officials from 8 of the 15 inspecting states told GAO they don't track.¹ On this course's reading, Texas's change in 2025 is the kind of before-and-after a future study could use, if the data exists. This course read no study of it. The course stops there.

What people get wrong

"Every US state inspects cars." GAO counted 16 with periodic safety inspection in July 2015, and Texas has stopped since ("No national test", above).

"The US minimum tread is 2/32 inch." It's 2/32 inch at inspection in the three states read, each measured its own way, and the federal 2/32 standard for cars is for states that inspect, not a rule on drivers ("Tread law, gathered", above).

"The emissions test and the safety inspection are the same thing." One comes from the Clean Air Act and checks emissions; the other is a state safety programme. New York does both in one visit; a Texas emissions county now does only the first.

"GAO proved inspections don't work." It found the research "inconclusive" and said the lack of studies "does not necessarily demonstrate that inspections do not have such an effect."

"A fifth of cars fail inspection, so inspection prevents crashes." A failure count shows defects found, not crashes prevented. The three US studies GAO read "did not find statistically significant differences in crash rates in states with inspection programs compared to those without."

"No inspection means nobody cares what state the car is in." Not in Texas, where DPS says driving without working safety features "is against the law" and the statute still makes driving an unsafe car an offence ("Between inspections", above).

"A rejection sticker gives me fifteen days to drive it." Not in Virginia: it's fifteen days to fix and reinspect (the Blacksburg case, above).

Practice

For your plan

If your car is kept in the US, add a state page to your car file, after lesson 21's test page. On it: your state, whether it inspects private cars for safety and how often, whether your area tests emissions, the tread rule and how it's measured, the fee if the page gives one, and the page's name and the date you read it. If your state has no inspection, write that down with the date, and next to it the checks from lessons 7 to 10, which are now the only regular ones the car gets.

Connections

Lesson 1, "What a car is made of, and why the handbook comes first", said that in Great Britain the driver, not the test, answers for a car's condition. Lessons 20 and 21 showed Great Britain's law and test; this lesson showed a country where the test depends on the state and in many states doesn't exist. Lesson 3 gave the federal rule on removing emissions parts, lesson 8 the state tread rules in detail, and lesson 11 the check engine light that the OBD test reads. Home Repair and Maintenance lesson 22, "Who may do what: reserved work, and the argument about licensing", is the same state-by-state shape for tradespeople. Lesson 23, "Recalls: checking, what's free, and 'stop drive'", takes the defects that aren't the owner's fault at all.

Go deeper

• GAO, "Vehicle Safety Inspections: Improved DOT Communication Could Better Inform State Programs" (GAO-15-705, August 2015), free. The evidence on both sides, and why the crash data can't answer the question.
• Texas Senate Research Center, bill analysis for HB 3297 (88th Legislature, 2023), free; the House committee's analysis sits beside it, and both were read here in full. The bill's stated reasons.
• EPA, "Vehicle Emissions Inspection & Maintenance (I/M): General Information for Motorists", free. Links to every state's emissions programme, for step 3 of the exercise.

Sources

1. US Government Accountability Office, "Vehicle Safety Inspections: Improved DOT Communication Could Better Inform State Programs", GAO-15-705, August 2015. Read: the full report, including appendices II and III, from the Internet Archive's copy of the PDF (capture 20260109053421), 26 September 2026; gao.gov refuses automated readers.
2. Pennsylvania Department of Transportation, "Safety Inspection Program" and "Safety Inspection Program Frequently Asked Questions for Consumers". Pennsylvania. Read: both pages in full, 26 September 2026.
3. PennDOT, "Pub 45: Vehicle Equipment and Inspection Regulations", 67 Pa. Code Chapter 175, edition PUB 45 (2-26). Pennsylvania. Read: § 175.80(d) and (e)(1) in full, 26 September 2026.
4. New York State DMV, "New York State Vehicle Safety/Emissions Inspection Program", for cars and light trucks. New York. Read: in full from an Internet Archive capture taken 26 September 2026 (20260926112204); dmv.ny.gov refuses automated readers.
5. Virginia State Police, "Vehicle Safety Inspection" and "Vehicle Inspection FAQs". Virginia. Read: both pages in full, 26 September 2026.
6. Virginia State Police, "Motor Vehicle Safety Inspection Manual", approved 17 March 2026 (19VAC30-70). Virginia. Read: 19VAC30-70-40 (fees), 19VAC30-70-50 (stickers) and 19VAC30-70-130 (tyres) in full, 26 September 2026.
7. Texas Department of Public Safety, "Vehicle Safety Inspection Program Changes Now in Effect", news release, 3 January 2025. Texas. Read: in full, 26 September 2026.
8. California Bureau of Automotive Repair, "Smog Check: When you need one and what's required". California. Read: in full, 26 September 2026.
9. New York State DMV, "About New York State Inspections". New York. Read: in full from an Internet Archive capture of 3 July 2026 (20260703020606), 26 September 2026.
10. US EPA, "Vehicle Emissions Inspection & Maintenance (I/M): General Information for Motorists". US federal. Read: in full, 26 September 2026.
11. US EPA, "Overview of Vehicle Inspection and Maintenance (I/M) Programs", EPA-420-F-21-067, October 2021. US federal. Read: in full, 26 September 2026.
12. 42 U.S.C. § 7522, "Prohibited acts" (Clean Air Act § 203). US federal. Read: § 7522(a)(3) in full, 26 September 2026.
13. Texas House Research Organization, "Bill digest: HB 3297", 4 May 2023. Texas. Read: in full, 26 September 2026.
14. Texas House Committee on Homeland Security and Public Safety, "Bill analysis: H.B. 3297, committee report (unamended)",
    2023. Texas. Read: in full, 26 September 2026.
15. Texas Senate Research Center, "Bill analysis: H.B. 3297, engrossed", 10 May 2023, including the author's and sponsor's statement of intent. Texas. Read: in full, 26 September 2026.
16. Pennsylvania Department of Environmental Protection, Drive Clean PA, "Information for Drivers in 'Other Counties'". Pennsylvania. Read: in full, including its list of 42 counties, 26 September 2026.
17. Code of Virginia § 46.2-1178, "Administration and scope of emissions inspection program". Virginia. Read: the whole section, live, 26 September 2026.
18. 49 CFR Part 570, "Vehicle in Use Inspection Standards", §§ 570.1 to 570.3 and 570.9. US federal. Read: in full through the eCFR, as in force on 1 September 2026, read 26 September 2026.
19. Texas Legislature, House Bill 3297, enrolled version (88th Legislature, 2023), Section 24 (amending Transportation Code § 548.604(a)) and Section 29 (effective 1 January 2025). Texas. Read: in full, 26 September 2026.
20. Texas Transportation Code, Chapters 547 and 548, § 547.004 and § 548.604. Texas. Read: both sections in full from Internet Archive captures of the official site (Chapter 547, 20251216230755; Chapter 548, 20250213061605), 26 September 2026; the live site no longer serves plain pages to automated readers.