Are Local Police Obsolete?

What is the point of a local police force? I understand that they serve the purpose of pulling over speeders, directing traffic, being present at large events, busting up high school parties, and keeping the peace, but my question is: does every town need one? At this point it seems that many police forces are required to make themselves relevant (quotas for speeding, etc). Why not focus them on things that are completely relevant in areas where they are needed.

Wait. Getting rid of police... Eradicating jobs! In this economy! Obviously this would have to be something phased out over time. I'm not suggesting that we suddenly drop all local police forces in the span of two years, but shrink them gradually and then consolidate them into streamline and effective county police forces. What does my county sheriff even do anyway? More importantly this will free up labor and capital that can be reinvested in urban areas where crime is not only a larger problem, but also where the police forces often lack the resources to successfully do their jobs (have you even seen the Wire?).

County police forces could still enforce the same mundane duties of underage alcohol consumption, speeding, parking tickets, and would still have the resources to stay on top of the occasional crime, the drunk drivers, and the larger drug cases.

We have to accept that the world is changing. Marijuana has already been decriminalized by more than a dozen states, and with prop 19 on the table in California this trend cannot be ignored. The legalization of marijuana would make it even harder for local police forces to not find themselves redundant. People want results from their police forces. County police forces could work on bigger cases and keep a watchful eye on the law, while at the same time giving more resources to urban centers that need more help. Most people could care less about the guy who is going 40 in a 30 to get home, or about the kids throwing down while their parents are away. But if they did, they could always call their effective and reliable county police force.