There is implicit context in every argument, which I made explicit in my previous comment. Arguing over the scope of the discussion instead of the substance is counterproductive to arriving at a meaningful conclusion. I bet you were loads of fun in your high school debate class.
>Example 2: a small town declares with pride that all streets controlled by the city finally have limits of 35MPH or slower, even though there are several roads capable of much higher speeds.
Other relevat comments that set the discussion:
>Or so simple as speeding when you drive? There are many laws which do not function as they should.
and
>By itself, speeding is a victimless crime: if you hit something or someone with your car, you were doing something wrong besides just speeding. The main idea behind speed limits is to "make criminals," in Rand's words. They are a tool that gives law enforcement a valid reason to pull over virtually anybody and everybody on the road. At the end of the day, the result is less respect for traffic laws and police in general, but more revenue for police departments, municipalities, and insurance companies.
So yes, it sounds to me like we're not limiting this to highways, but rather to the governments right to set things like speed limits and whether those limits are effective. Now, if you think that there should be a right to set speed limits in town but not on highways, we need to establish that.
You, yourself, included non-highways in this discussion. I respect your decision to exclude them but clearly you are limiting the scope of the discussion from what you personally set it at.
And of course the scope matter, the relevant facts change(i.e. the politically influenced decision to lower speed limits to 55 MPH) when you change the scope. This isn't a matter substance, it's a matter of deciding what we are all talking about. If you want to just talk about highways, you should do that, but clearly not everyone else feels we are talking exclusivly about highways or they wouldn't have brought it into the discussion.
My other comment was in response to your assertion that speed limits are set by engineers. It was a simple proof by counterexample. I don't see a point coming out of all this, so I'll most likely withdraw from the discussion now.