A couple of years ago, we found the warf restaurants to be too crowded on Mardi Gras Saturday night (~9PM). I drove up to the sea wall to see what was open and the police were restricting traffic sending visitors back to the highway. It wasn't like there was a crowd cruising around and yet the road was blocked.
There was also an incident in Houston with cruising (or parking) in one of the black neighborhoods in town. I know that it was covered on KCOH 1430AM (a black station), where they actually supported telling the crowd to hit the road. I don't know that it blipped on the radar of citywide news.
Another precident. Houston youth used to "cruise the curve" of lower Westheimer and were run off by repeat police checkpoints where every car was searched (don't want to be searched and harassed? don't go). The end of "cruising the curve" led to some area nightclubs opening their doors to the 18+ crowd on weekends. Then mayor Whitmire heard complaints from parents about their kids that were staying out all night (hello, 18 is adult). The police started to (and continue to) enforce a law that was passed in 1968 but not enforced until the 1980s banning dancing after the sale of alcohol ends. This led to "after hour" clubs in Houston, where people could pay to keep dancing by going to another club. It really didn't help Houston streets to force drunk people to leave bars at 2AM (instead of letting them stay for a couple more hours to sober up).
I know all of this as someone who grew up through Houston's nightlife during those years.