My opposition to this idea is strong enough that “no” would be considered full support by comparison. The best I can say about the idea is that it’s childishly optimistic and utterly impractical.
To start with, that would force all drivers to have a GPS. Granted, many of us do already (smartphones in our pocket) but that is by choice. If you don’t have enough privacy concerns to see why this is bad, then I’m not sure you would be able to understand why all the opposition so lets just move along.
Newer cars would require some retrofitting work, but even if it’s as simple as just replacing the chip in your ECU (about as difficult and time consuming as pulling two Lego bricks apart and putting them back together), that does not mean that 100% of cars on the road will have the system. I would go so far as to say that the percentage of cars on the road that would require major work alone is enough to severely limit the already-marginal benefits gained without adding the number of cars that just haven’t been in for the more minor work it would take to get a post-1996 car to work with the system.
Older cars like mine don’t have a computer controlling the engine. I have no injectors to shut off to limit the amount of fuel my engine gets when I tromp the gas, which is the usual method of governing a car. You’d have to do a a lot of work to modify my car to make it work. And I would not be willing to allow my car to be screwed up; if you knew the issues with “Malaise era” attempts at bolt-on emission controls, you’d understand.
Some may say, “Get a new car!”. I will tell them to fuck themselves. And they’d be telling every classic car enthusiast and anyone who cannot afford a new car that they are not allowed to drive, which in turn would prompt me to give graphical suggestions of exactly how they should fuck themselves. Granted, I might consider it if they had a plan to buy me a brand new car that could meet my needs, but then they’d have to do that for everyone, and I don’t think anyone’s pockets are that deep.
There are a few other reasons beyond the impracticality of implementation, but they mostly boil down to me having strong opinions on how much freedom I am willing to give up for the illusion of security. There is also a dash of cynicism about the potential for abuse. The technology involved would be hackable over a remote connection, and not all people with the skills and equipment to pull that off wear badges, so we’d probably be trading one set of safety concerns for another, the difference being that we have a few decades experience dealing with speeders and none stopping people from hacking your car.
And what would we really get from all that? Would it really be worth it? Would you be willing to spend billions (trillions?) of dollars and/or wipe your ass on civil liberties while creating a huge security concern that we couldn’t deal with just so you don’t have to tell that kid in the dropped Civic with a fart-can to slow down?
Edit – I almost forgot the safety concerns. Yeah, your car is limited to the speed limit but half the cars on the road are not. You just obstructed traffic, possibly causing more accidents than if everyone were going the same speed even if it was a bit over the posted limit. To my mind, creating a greater danger than the one you tried to protect against makes anyone who supports this idea either a hypocrite or an impractical idealist who doesn’t know how the really real world really works. Then there is this.