I suggest four initial levels of label:
I tried to design this proposal to reflect and link the things that cause the most local pollution with the things that will best manage that local pollution, within the bounds of what most localities are allowed to regulate.
Around town driving causes the most pollution, as it is stop-and go and generally gets the worst mileage. When around town driving is combined with a V8 engine and horrifying mileage, the impact on local air quality is significant. Conversely, well maintained, smooth roads and properly-timed lights can improve the mileage vehicles get when driving around town.
Since the medallion would be right under the dealer label, it would be very public as to who was driving the worst vehicles, and who was selling them. I think it's generally known that certain vehicles are worse than other vehicles, but this system would give us a way to actually measure and compare as we're driving around town. I think this is critical. One of the biggest reasons we Americans do anything is because our neighbors are doing it (look at Republican voting patterns. ;-)). If there is a de facto mark of shame, right on the back of your car, you might think twice about buying the Lincoln (brown label) when another SUV with marginally better mileage (orange label) would work just as well. It would force people to drive around and de facto say "yes, I know this vehicle is among the worst polluters on the road, and I choose not to care."
Similarly, if people notice that every car sold by dealership X seems to have a brown sticker, that dealership becomes associated with pollution. Perhaps the dealer will introduce incentives to folks for buying more mileage-friendly vehicles in the interest of improving their local environmental reputation.
Finally, this system allows localities to direct and control how they want to manage local pollution. In Lynchburg, the town may not care too much about the mileage of its vehicles, and thus may choose to impose a $0.10 surcharge on the brown label, while in Fairfax, they may make full use of the system and slap a $100.00 surcharge on the brown labeled vehicles. Localities could even implement escalation clauses, so that every other year, the mileage bands increase by 1 mile per gallon. Thus, by 2010, vehicles in the area would need to have more than 33 miles per gallon, around town, to qualify for the green sticker. Properly structured and implemented, this proposal may even allow some areas to eliminate the car tax entirely for green labeled vehicles.
The best thing about this proposal is the fact that it does not impose national standards for gas mileage on car manufacturers, and thus is both politically feasible and locally defensible. It doesn't say "you must I mprove your mileage" it simply says "if you don't, your personal property taxes might go up." It puts a cost on behavior and choices, rather than imposing behavior and choices.
For a fantastic analysis of driving habits and their impact on fuel efficiency, see this article: Improve MPG: The Factors Affecting Fuel Efficiency from Omninerd.
Sadly, the reality is that labels are for the consumer who is buying, not for after the purchase. As such, I think most people who have Yellow, Orange, or Brown tags would simply pull them off right after they leave the dealer. And those who don't are probably proud of the fact that they pollute.
But the taxation aspect, regardless of whether the label is still on the vehicle or not, is a very good idea. I'm a big fan of the government getting involved in the manner you describe: by putting a cost on behaviors rather than banning them. Well stated.
For me, the key is the location of the sticker - on the back near the dealer label. If it's part of the registration, no one will see it in traffic. It's seeing it in traffic that's key in my opinion.
Although I like the idea about color coding the inspection stickers. People already don't have a choice with that one so there's nothing to get bent about.
Thanks for the good reminder about the lawnmower problem. The solution to this problem is very easy and inexpensive, and can be implemented now. I think this solution is very comparable to replacing 60 watt incandescent lightbulbs with 14 watt flourescent bulbs in terms of ease of implementing and cost savings to the consumer.
BTW, the same solution also applies to those awful gasoline engine weed whackers and blowers: They are available in a rechargeable battery and 110 volt a.c. version as well.                       Tom C.                       Â
I use a rotary blade push mower to cut mine. No electricity, no gasoline, and I get a halfway decent workout, burning calories and getting some exercise.
Win-Win-Win.
Of course, I'd never try that on the 1.5 acres of lawn my parents have, but that's a different cup of tea. For that, I like the color-coded lawnmower paint idea.