Very true - regulation undeniably accelerates technological advancement for emissions technology ... I think that the key is just striking the right balance. I was just trying to express that in the case of Diesels, the EPA may have done too much too fast.

As an aside, even when the technology matures and goes from "sucks"->"unquestionably better", all of this is not without cost. New car prices have significantly outpaced inflation in the past few decades. For instance, 50 years ago the base model mustang would have cost ~$18k in today's dollars, and the 2015 base model mustang is ~$24k. To many people a forced 33% increase in the cost of a base model vehicle is not trivial -- this is something that disproportionately effects low-income folks. Since the USA is so spread out, in many areas where population density is low it's basically impossible to get by without a car. (I chose the Mustang because somebody else already did the legwork - source: http://fortune.com/2014/10/17/ford-mustang-cost/ )

In my home state of Michigan, we don't have mandatory emissions testing, which I personally see as a good thing. Cars don't last much longer than ~15, maybe 20 years here anyway due to the extensive use of salt on the roads during the winter, so they get replaced quickly enough with newer/better/cleaner models by virtue of the fact that they rust away. I see a lot of people with cars who couldn't afford it if they weren't allowed to drive beaters. As you may have guessed from my post on shopping for tractors, I happen to live in an area where public transport isn't practical for much of the suburban/metro area (Grand Rapids/Holland), although we do have it (to some extent) in the more densely populated sections of town.

Interestingly, with the revitalization of downtown that's been happening around here, many poor people are being pushed into areas where public transportation is either inadequate, not available, or completely and totally unfeasible (if the houses are 200-500+ feet apart, or the small town has a population of 1,000, it just doesn't make sense).

Mustangs got more expensive, but that's only one data point :)

http://blog.caranddriver.com/are-cars-getting-less-affordabl...

Heavily salted states certainly have an easier time justifying no emissions testing. You start out with a "known good" (regulated by the EPA) and count on cars to expire quickly. Compare to California, which thanks to gentle climate still has a huge fleet of 1980's cars on the road.

That's about the only good thing about the salt (aside from not dying on an ice patch :) ). My wife's 2005 Pontiac G6 with 120k on it is already starting to rust. I dumped my last car at ~9 years old with ~130k because it was starting to rust.

OTOH, I have a '96 Camaro that I only drive during the summer that doesn't have a speck of rust on it (driving an RWD car in a northern state during the winter is a good way to end up in an accident). It's amazing how big a difference the salt makes ... and dirt roads -- I think they kill cars even faster than salt. We are lucky enough to live on a paved road, so I don't have to worry about that particular problem.

Yep. I have a '97 Honda Del Sol. I did drive it in the winter some for a while but haven't for a number of years; I live in Massachusetts. Now, whenever it's in at the dealer, I invariably have a mechanic or service manager commenting on what great shape it's in. (It's not in mint shape by any means but it doesn't have serious rust other than the exhaust replacements that it's inevitably had.)

My current 2013 Ford Focus sticker price matched up exactly with inflation on the sticker price of the 97 Escort it replaced.

I was kind of amazed given all the safety improvements.

I did get 250,000 miles out of the escort before the salt rusted out too much.