In S.Korea, you never see a cop on the highway. They just have speed cameras on accident prone zones and put up camera warning signs miles ahead so people actually slow down. It seems pretty effective.
I also believe it came out that the company providing the cameras was getting a cut of every ticket issued, leading to a tendency towards false positives. The program wasn't profitable for the state and people complained so much that the cameras were gone a short time later. I remember most people would slam on the brakes just before the stationary cameras, cruise through at exactly 64 or 74 mph (the cameras went off at 10 mph above the posted limit) and then accelerate to whatever speed they wanted. It was way worse than people just speeding.
Maybe it works well in S. Korea because the incentives aren't so screwed up, but here in the States "Cameras" mean someone is getting a cut and the people are getting screwed. The camera's get set up in the best places to get revenue (downhill when the speed limit changes from 65 mph to 55 mph around a bend so you don't even see the sign before it's too late).
Pretty much no-one seems to obey the official speed limits, instead opting to go with the subjective "safe speed" as per the current weather conditions, traffic flow, visibility etc (just like the article explains).
Is your experience driving in S. Korea that different?