Joe Steffen has taken issue with the existence of Maryland's Emissions inspection regime, using Governor Hogan's move to make the Emissions Testing a 24-hour kiosk service to make the point that the Emissions testing shouldn't exist at all. This isn't a libertarian or conservative idea.
After all, it is the right of property owners to prohibit the dumping of trash onto their property, and if someone tries to turn someone else's front lawn into a trash heap, the police are called and the person dumping is charged with littering. Straightforward, no?
Now imagine that cars, instead of emitting smoke, instead ejected a small amount of black sludge every so often as they traveled down the road. The sludge would end up in people's lawns and on their buildings, all along the highways, and likely cover parking lots and roads.
Obviously, property owners would object strongly to the sludge being dumped on their property, and the public would object to the roads and highways being in it. The government would clearly be justified in passing laws prohibiting the dumping of this sludge just anywhere, and in requiring capture technologies to stop the sludge from ending up everywhere or conversion technologies to turn it into a harmless substance.
But instead of sludge, vehicles emit smoke - that is, gases - that, if unfiltered, do contain some hazardous substances in it. Modern vehicles are required to come equipped with technology that renders the vehicle emissions less harmful and destructive. The justification is simple: like with the sludge and trash, drivers cannot simply dump their waste onto other people to deal with. The person who generates the waste must bear the burden of dealing with it.
The Vehicle Emissions Inspection Program test simply makes sure that the vehicles driven maintain the ability to deal with the waste generated by their operation. While it's not immediately obvious that a car contributes to air pollution, the combined output of all the cars in an area, especially an area so dense as Maryland's urban center, is quite significant.
All the VEIP does is insure that each driver is responsible for themselves, which is both a core Conservative and Libertarian principle.