Emissions testing has been a controversial subject ever since its inception. Though most opinion polls show widespread public support for clean air in general, few motorists show any enthusiasm for emissions testing when it involves their own vehicles. And most are reluctant to spend money on emission-related maintenance or repairs.
As long as most vehicles pass an emission test, most people will go along with a program, pay a reasonable test fee and tolerate waiting in line 20 to 30 minutes once eery year or two to have their vehicle tested. But when their vehicle fails an emissions test, their attitude often becomes angry and resentful. An emissions failure creates stress and anxiety because of what comes next.
A failure means finding a shop with technicians who are competent enough to do emission repairs, making a service appointment, being without a vehicle for half a day or more, having to spend up to several hundred dollars or more on emission repairs they may not even believe are really necessary, and then taking the vehicle back to the inspection station for retesting. And if the vehicle fails the retest? They feel even more frustration and anger as they bounce back and forth between the repair facility and test station. Consequently, there has been a lot of public backlash against emission test programs that are too stringent or fail too many vehicles.
A growing number of people today are questioning the value of emissions testing, and wonder if it is making any significant difference in reducing air pollution. U.S. Environmental Protection Agency (EPA) statistics show that air quality is improving in most areas of the country, but the data fails to show a direct link between the reductions in pollution from mobile sources (vehicles) and emission testing. Some areas that have no inspection/maintenance (I/M) programs have shown just as much improvement in air quality as areas that do emissions testing.
Most of the reduction in emissions from mobile sources is being attributed to changes in the vehicle population. As older vehicles are replaced by newer, cleaner running vehicles, the amount of pollution from mobile sources has gone down and will continue to decline as time goes on.
Not only are new vehicles much cleaner, they also stay cleaner for a longer period of time. Even so, older vehicles (10 years old or more) continue to be a significant part of the vehicle population and represent a major source of pollution. Consequently, periodic emission testing is seen as a necessary means of policing these older vehicles.