People drive more safely when they can SEE the police car. If safety is the goal, the officer would be much more effective driving down the road at the desired speed. Hiding around corners and/or using unmarked cars to catch people being bad does little to nothing to stop people from speeding.Totally different issue, and at this point, totally hypothetical. The reality is we do have speed limits. A coinciding reality is that when police are around, enforcing not only speed limits but other traffic offenses, people drive "better" for the most part.
How about something from the last 10 years on urban/suburban streets?
As another derail (can you derail a thread about a wheeled vehicle?) it is not really a surprise to me that people drive "reasonably" in a no speed limit environment. Roundabouts require a certain amount of reasonableness to be safe, and they are safer (so far) than 4 way stops or 4 way stoplights.
For whatever the reason, the trend is more and more to hide the officer and pull people over. Whether it is to generate revenue or interactions with people that could lead to other charges/confiscations is something that only the departments can know.
How about something from the last 10 years on urban/suburban streets?
How many police cars do you see looking for speeders on urban/suburban streets? There is also a world of difference between speeds on those streets and highways.
The speed limits are kept artificially low in many instances. If they set the limits where the majority of the drivers were actually driving, there would be much less of an issue.