Emission testing unintentionally targets the poor since they are the least able to afford newer cars that would pass the testing.
From the Illinois Review:
We often talk about ‘regressive’ taxes, burdens that fall unfairly on the poor. This is one of the biggest of such burdens, because it’s precisely the working poor owners of old cars who are hit hardest by the well-intentioned goofiness of emissions testing. Consider:
It’s just a huge waste of time for newer cars, because of course they pass. The number of newer cars that fail are such a statistical minority that the pollution they produce is too little to be worth the bother.
For the old cars that we would expect to fail, the additional cost of bringing them up to code is so onerous on these mostly working-poor car owners, it just puts them further behind. That cost, specifically relative to the budgets of the working-poor in question, is utterly unjustifiable; for people who must count every transportation penny, it often has the effect of causing them to postpone much more important car-related purchases, such as auto insurance, brake repairs, alignments, and other issues that pose genuine safety concerns.
The cost of maintaining this service – all these buildings, public employees, etc. – contribute to the unsustainable government budgets of states like Illinois. This cost drives employers and entrepreneurs out of state, drying up the tax base, necessitating ever-larger collections from an ever-shrinking pool, and again contributing to the reduction of opportunities for the poor and lower middle class to climb upward.
And the timing itself has been insane all along, since the birth of these metropolitan emissions testing centers coincided with the (mandated) popularity of unleaded fuel and the catalytic converter. These advancements already had the country on a successful and fast-moving trend toward cleaner air; the emissions testing center archipelago was, frankly, obsolete almost at its inception! (How do you like that? I buried the lede.)