“.in most cities, the police are used to collect on fees/fines with bogus traffic violations.”
Speed traps and the like are not legal for cities to do in Texas. Only (I think) 3% or some small percent of city revenue can come from fines and penalties.
Postage stamp sized towns every 10-20 miles would have a lowered sped limit for a short stretch of road. Many of these would have the speed limits drop 20-30 mph in a single step with no coasting zone such that even slamming on the brakes you would still be “speeding”. The towns involved in this scam derived essentially all their revenue from speeding fines. The state ended this practice by establishing uniform state standards setting and signing speed limits and mandatory coast zones for slow downs.
A separate scam was run by a small number of sheriff departments. This was not a rogue deputy here or there but department level corruption. The usual way it worked was to pull an out of state car over at night for some traffic violation then shake the drivers down for big $$$ often by a frame up. It was so bad, the feds got involved (violation of constitutional rights) and ran stings that snared a number of deputies. Deputies and sheriffs went to prison over this and others as well.
You are correct, due to the town of Splendora, that took in a narrow swath of a highway and ran its city off traffic fines,