Smog Tests & Safety Inspections

Every year, millions of motorists are required to submit to either an “Emissions Test” or a “Safety Inspection” or both. Few people stop to question whether or not these tests and inspections actually accomplish anything. It may come as a surprise to Easterners, but most of the Western states, including California, have no requirement for a “Safety Inspection”. A detailed analysis of traffic accident rates and causes shows that states with no inspection laws suffer no increase in traffic accidents. Insurance companies agree, and they do not push for safety inspections because they see no benefit in having them. People just THINK they keep unsafe cars off the road, but statistically, they make no difference. As for emissions testing, today’s automobiles with their computerized controls and OBD-2 engine monitoring systems, literally force drivers to keep there cars operating properly. The vehicle monitors its own emissions and does not need to be “tested” to maintain acceptable air quality. Politics plays a large part in determining who gets tested and who does not. The failure rate, 3.5% or so, means 96.5% of the cars tested pass! For these people, the test is just another $35-$45 down the drain, a transfer of wealth that supports a multi-billion dollar a year testing and repair industry. Does testing improve air quality? Not hardly… If you look at a pie-chart of the Sources Of Air Pollution, passenger cars make up a relatively modest percentage…And if only 3.5% of that group fails, you can’t expect any measurable difference in overall air quality even if you removed those “dirty” cars from the road. (Lets not forget only half the cars are ever tested! The other half are exempt from testing!) But they are NOT removed from the road, most of them are “repaired” so the Check Engine Light goes out…Does that repair reduce their emissions to zero?? I think not. It might not reduce their emissions at all…



As a tool to improve air quality, emissions testing is a complete waste of time. It has evolved into a profitable “industry” that is now self-sustaining…

I think emissions tests made a lot of sense back in the days of feedback carburetors and smog pumps when there really wasn’t much connection between the emissions equipment and the running condition of your car. Aside from the temptation to remove the stuff to get better performance, a lot of people probably wouldn’t ever know when it wasn’t working because it wouldn’t affect how the car ran at all. And aside from emissions equipment, they also simply forced you to keep your car in tune. I think you really can’t deny that the combination of emissions mandates and testing made a major difference in areas that had serious smog problems.

These days I’d agree they’re not necessary-- it’s all so integrated that there’s really not performance gains to be had by hacking it off and you know when it’s not working. And cars don’t wander out of tune like they used to either.

I’m actually somewhat surprised that the failure rate would be as high as 3.5% these days. The last smog state I lived in exempted cars older than IIRC 18 years and so that means that all but the very last carbureted cars should be exempt by now. I never personally failed an emissions test in the various FI-ed early-to-mid-80’s fuel injected cars I drove and I will admit that some of them were not as well maintained as they could have been.

A detailed analysis of traffic accident rates and causes shows that states with no inspection laws suffer no increase in traffic accidents.

Would you please share the details of your “detailed analysis”? Who conducted the analysis? What methodology did they use to collect data?

Insurance companies agree, and they do not push for safety inspections because they see no benefit in having them.

Of which insurance companies do you speak? Will you please provide the source of this statement?

People just THINK they keep unsafe cars off the road, but statistically, they make no difference.

If you are going to refer to statistics, don’t you think you should include them and their sources?

The failure rate, 3.5% or so, means 96.5% of the cars tested pass!

Where are you getting this 3.5% figure?

If I am to believe your statistics are valid (which you have yet to prove), with about 62,000,000 cars owned in the USA, about 2,170,000 cars fail! [EDIT: To be more precise, 2,170,000 cars would fail if all cars were tested.] That’s 2.17 million!

The last time you quoted the failure rate, it was 3%. Why has the number gone up?

Sorry, but you are throwing out a lot of hot air without providing any proof. If you have a point to make, make it properly, so it passes the sniff test. When someone throws around unsubstantiated opinions as fact, and statistics without sharing their sources, I have a hard time taking it at face value. How about sharing your sources for a little peer review?

And then we can move on to those pesky CD players with their spinning disks.

Think “no moving parts.” USB drives for all!

Agreed. If he would just make a real case for his point of view, I might be convinced. I am trying to keep an open mind.

Here in DC they recently dropped safety inspection every 2 years.
In MD they do a safety inspection only after initial car purchase.
Up until now it was always cars with Maryland plates that had tail lights and headlights out.
I once get rear ended in the rain by a Maryland car with bald tires.

computerized controls and OBD-2 engine monitoring systems, literally force drivers to keep there cars operating properly

No, people just ignore the check engine light.
Here in DC the emissions test consists of reading the OBD-2 port, if the vehicle has it.
Older cars used to run on a dynamometer, but now they just do an idle test

Let’s suppose 3.5% of the cars have faulty emissions. If they are gross polluters putting out 10X as much pollution as normal (not unusual if the cat converter can’t do its job for whatever reason) then those dirty engines produce 35% as much pollution as the rest of the “good” cars.

today’s automobiles with their computerized controls and OBD-2 engine monitoring systems, literally force drivers to keep there cars operating properly.

Until they use the electric tape mod over the light. :slight_smile:

You have made like remarks a number of times in the last few days and I have been tempted to disagree. This time you spelled out the reasons for your comments and well I guess I have to agree with you on this. I might not be as strong on the point as you. I suspect there is some minor improvement, but not enough to justify the cost in many areas.

Let’s face facts, we don’t have the technology to really produce clean automotive transportation. I might argue that mass transit can be much cleaner overall, but to change over to a mass transit system would be extremely expensive and politically impossible. Frankly I believe that is the only answer to the problem, but we need to solve the problem of public opinion and the lack of infrastructure, two very difficult and expensive projects. In the long run I believe it would be best, but I guess I am too old to expect to see it happen.

Thanks for the clear well thought out explanation.

“Let’s face facts, we don’t have the technology to really produce clean automotive transportation.”

But we do, Joe, we do…Todays cars are squeaky clean, grams per mile are almost nothing now. Today, it’s just a QUALITY issue. Building a clean car is easy. The hard part is KEEPING them clean for 200,000 miles. The manufactures want the motoring public to pay for restoring failed emissions systems after 80,000 miles. But for a few dollars more, they could BUILD cars that stayed clean for 200,000 miles and therefore retained higher value and did not need new catalytic converters or ten or fifteen different “modules” at four hundred bucks a pop which destroys the value of the car…

So far, nobody has posted anything that refutes my argument…Yes indeed, failed, “dirty” cars can be VERY dirty…in some cases 100 times dirtier than a “clean” car…I agree! But there are so few of them, it just doesn’t make any difference in air quality…The “Classic Car” and Motorcycle groups go untested but they are all “gross polluters” compared to a new car…But again, they get a pass because their numbers are so low they just don’t make any difference…The heavy truck industry, construction equipment industry, railroad industry, airline industry, all are “Gross Polluters”…No emissions tests for them. Why? When you make huge political contributions, you don’t have to worry about stuff like this…Railroad locomotives and Kenworth tractors don’t have CEL lights or EGR valves that can develop “low flow” problems leading to costly repairs…

Do you even read opposing views? Someone in another thread brought up the fact that tractor trailers are now being tested. See Diamond-Chevy’s post at http://community.cartalk.com/posts/list/2135979.page

Big trucks are tested semi-annually, just like cars, and they’re also tested randomly right on the side of the road, at the authority’s discretion. Plus, if one fails, the truck must be fixed, regardless of the cost to repair. I don’t know why the myth that trucks are exempt continues to be presented as fact.

The sad part is this guy agrees with everything else you have said, so I am not sure why you would ignore his attempt to correct your misconception.

I don’t know where you are getting your information, but I wish you would share it with the rest of us.

Please share your information sources so you can convince me you are aren’t just regurgitating Fox News propaganda.

There was actually a bill presented, luckily failed to test lawnmowers in WI, I keep thinking of the fact 80% of fuel is used by industry, and you want to check my lawnmower that uses 2.5 gallons of gas per year? Something seems wrong with this picture.

Most Diesel tests involve little more that a simple opacity reading… They shine a light beam through the exhaust and if more than 20% is absorbed by the smoke, you fail…They call that a “test”…An hour later, the truck is back, its fuel tank full of kerosene, “it passes fine now, no problem!” In many states, “fleets” are allowed to “test” themselves. That’s SURE to improve air quality…

It’s not a simple light. It uses infrared and ultraviolet lasers to measure particular gasses and particulate matter. The states are getting sophisticated equipment like this through EPA grants now that the EPA is being allowed to do its job again. Europeans have been using this technology for decades. Sweden began in 1995. Unfortunately, it has taken more than 20 years for the technology to make it here because of obstructionists. The device they use is called “differential absorption lidar,” or DIAL. Basically, it sends two laser beams through the air, one at a wavelength that reacts to the target element being measured, and one at a wavelength that doesn’t react to the target element. Then it compares the wavelengths of both laser beams after they pass through the exhaust fumes. Google “differential absorption lidar” if you want more information.

One thing I noticed when I worked as a truck driver is that professional drivers gossip more than middle school girls, only adolescent girls are better at accurately sharing information. If you tell one truck driver you are using infrared and ultraviolet lasers to measure emissions produced by his truck, by the time he tells his buddy, all he says “uh, all they do is shine a light through the exhaust.”

Again, I would really like to know where you are getting your information. It is a mixture of out-of-date and dead wrong.

Sniffer tests worked for almost 2 decades before OBD2. They can still work now. Test what actually comes out the pipe. If there isn’t some device to fake OBD output, it isn’t because it can’t be done.

Have you ever seen a British MOT test? It is mostly safety-related (they also check stuff like the license plate to make sure it’s within specs) and it is pretty thorough. I know they check the brakes (minimum thickness), all of the lights, seatbelts, steering and suspension components, etc. A failure anywhere means a total failure and the car needs to be fixed and re-tested. Retests are free if re-done within a week or so. Often repairs are done and cars are retested same-day.

As for emissions checks: there will always be old cars on the road. Cars whose systems weren’t perfect then and are far from perfect now. They need to be tested and, quite frankly, when a cop sees them wheezing down the road, emitting* more smoke from the tailpipe than a house on fire, they need to be pulled over and ticketed or the car impounded.

Yes, cars ultimately are not the biggest single contributor of pollution but just because it is inconvenient to you or an expense for you isn’t a good enough reason to stop testing them all. Because, using that logic, we should just stop testing everything that isn’t “the biggest contributor” and then because we’d be singling just one industry out, they’d whine and moan and we’d stop testing them or forcing them to improve, too. Then we’d be breathing a soup of smoke and filth all day long.

*I believe in Oregon the law has a minimum of three or five continuous seconds of visible smoke to be considered excessive/in violation of the law.

Something seems wrong with this picture.

Especially since most lawn mowers have their deck rust out before the carburetor needs work.

“Have you ever seen a British MOT test? It is mostly safety-related (they also check stuff like the license plate to make sure it’s within specs) and it is pretty thorough. I know they check the brakes (minimum thickness), all of the lights, seatbelts, steering and suspension components, etc. A failure anywhere means a total failure and the car needs to be fixed and re-tested. Retests are free if re-done within a week or so. Often repairs are done and cars are retested same-day.”

But do these tests and inspections ACCOMPLISH anything? When you compare the accident rate, the number of fatalities per mile driven, it makes no difference whether cars are inspected or not…The burned out headlights, broken seat belts, cracked windshields, worn brakes, air-bag lights just don’t translate into a higher accident or fatality rate…California which has NO safety inspection enjoys a lower accident and fatality rate than New York which has a traditional “Brake & Light” inspection. Drunk Drivers are the REAL problem, not worn brakes and cracked windshields…The Testing & Inspection Bureaucracy swears their work makes our highways safer, but they can’t prove it…They just live off it…

and just think, a few years ago some idiot in the cali. government changed a pending law -that had something to do with senior citizen housing- in the final hours of becoming a law to say something to the effect of “all cars must have roadside emmisions tests every 6 months”.

SEMA caught that one and had SAN members phone in within an hour.

European safety tests are done for a number of reasons. Most European roads, including superhighways have very little in the way of continuous shoulders!!!

In North America when someone’s car breaks down he pulls off the road and calls the AAA or other service. The traffic continues on. In England and other countries in Europe these frequent breakdowns would cause massive traffic jams due to the lack of shoulders.

Where I live here I see about 20 cars or so per week stranded by the roadside. After 5 weeks in England, Scotland and Wales we saw only ONE (1) car stuck by the roadside. Countries with annual checkups have fewer breakdowns. I don’t know whether the British government cares about personal safety and injuries. All over the world, 85% of car accidents are caused by driver error, and the remaining 15 % divide into 10% road and weather, and only 5% mechanical failure.

There are some exceptions; don’t take a cheap bus tour in Mexico (Night of the Iguana) or Peru!

My personal feeling is that unless emissions testing is performed universally nationwide and by measuring actual emissions rather than checking for stored OBDII codes, it’s really only a feel-good measure. The requirements that manufacturers of new vehicles have to meet are extremely stringent, and post-sale testing in some areas and not in others is a sense of false security. Some counties in NH have to test and some not, based on air quallity readings, yet it’s been repeatedly proven that the associated contaminants are brought in on prevailing winds from the midwestern industrial states.

Trucks are another issue. My car pollutes almost not at all, and I drive it perhaps two hours a day. Diesel trucks with loads pump enormous amounts of pollutants into the air and many run 16 to 24 hours a day continuously. Cross country trucks aren’t as bad, because a pooorly running engine costs them in fuel use, but local trucks such as dump trucks and flatbeds that haul the heavy equipment are commonly pouring out huge black carbon clouds…which means they’re also pouring out CO at enourmous rates. I’ve yet to find a study on how much the typical truck pumps out, but I’d like to.

It seems to me that if the EPA were not such apolititcal organization it could make its real gains these days by addressing trucks rather than continuing to tighten the screws on cars.

Safety inspections are IMHO of questionable value. Some states do them well, others not. Many do none at all. I too have seen data from the National Insurance Institute that does not show a difference in accident rates or magnitude from inspections.

Central MD has emissions tests every other year. The balance of the state does not. It is only where smog is heavy that the tests are run. Of course, that’s where most Marylanders live. A lit CEL is an automatic failure. This encourages people to either get it repaired or get rid of the car. MD does allow the driver to continue using the car if the spend a certain minimum amount for repairs. You have to bring the receipt to the emissions test site to get credit for it. Traffic in the Baltimore/Washington area is the heaviest in the US. I’m glad there is emissions testing.