Cops and Cowboys

Can someone please explain to me the purpose of having roadblocks in peak-hour.
For three days running now I've encountered roadblocks on different roads and highways in and around Johannesburg. The first roadblock happened on the Golden Highway travelling from Alberton to Uncle Charlie's. Thankfully I saw the back-up from a distance and was able to take a detour home via Rifle Range road. The traffic was backed up from Voortrekker Road Off ramp in Alberton all the way to Uncle Charlie's. That was ten minutes into the roadblock, and God only knows how much further it went ten or twenty minutes after that. In my estimate, the distance of the congestion created was in the region of about 10 to 15km's.
The next day I encountered another roadblock at the Maraisburg off-ramp. Thankfully the roadblock had just been set up and I was able to get through. On my way back(travelling on a different road), the traffic had already backed up to about 5 km's from the direction of Soweto. Once again this roadblock was in peak-hour. The third one was on the Soweto Highway heading from Booysens to Soweto. The cars were backed up at least 3km's within just a few minutes that I sat in traffic. The reason why I encountered all these roadblocks, is simply because I'm trying to find the best route home after picking up the missus from work.
Fuckin hell, maybe the cops know something I don't. Perhaps in training they learn that this would be the best time to catch car jackers, bank robbers, arms dealers or search for stolen vehicles.
To me, with my zero police experience, exept from the otherside-of-the-fence-perspective, it makes absolutely no fuckin sense. Most of our country's citizens, and I'd venture to say at least 90%, are working people trying to get home at this time of day. If the cops are trying to show the public that they aren't going to take shit this holiday season, they're doing it the wrong fuckin way. A bank robber must be downright fuckin stupid if he thinks the best time for a getaway would be during peak-hour traffic. If I wanted to steal a car, would I fuckin honestly attempt it at this time? I might as well walk into a cop staion and confess for thinking it. Speeding is impossible in peak-hour. So excuse me for being hugely Titanic-like dumbfounded.
Instead of munching their fuckin doughnuts at crown interchange in the mornings(Sometimes as many as 12 cop cars congregate there in the mornings), they should be part of the traffic. They cause more congestion standing at the side of a road, than they would if they were driving up and down between the traffic. That would be my solution. Give each cop a route to travel on the highways and byways around Jo'burg. Alternate the routes and swop the cops around, so that at any given time there's a cop car within k's of each other, either travelling in opposite directions or within a reasonable distance of each other, travelling in the same direction. Your reaction time to an emergency is so much quicker when you are moving, than stuffing your face or posing as a Cowboy by the side of the road. If a cop is alert enough(one can only pray for moments like these) roadblocks should only ever be necessary to prevent a getaway of some sort.
Maybe it's good that I'm not in Law Enforcement(I just wanna laugh when I say that out loud).

This rant may be just because I have such a deep-set paranoia when it comes to law-enforcement(ha, ha, ha).

And would all you fuckers waiting for the holiday traffic to thin out, please get in your fuckin cars and fuck off already, so that the few of us still working can get to and from fuckin work a little easier. Thank you very fuckin much!