The genius who came up with the idea to put speed camera signs up everywhere needs to be knighted. There's so many dotted around and often nowhere near cameras that the people who are likely to speed ignore them. So when there is a camera, fixed or mobile unit, they are possibly more likely to get caught.
We live on a road that has houses on one side of the road as it leads ivy the village. There's a slow road out of the village until after the train station and a road that Ts into it. From that point a lot of drivers floor it until there's a line of parked cars and it's slow again. Then they speed up past our house before more parked cars then the open road. All cars end up 30 to 40mph with some looking like 60mph between slow sections. It got changed from 30mph to 20mph last year. Nobody sticks to 20mph.
Earlier this year they put one chicane in going out, further out from our house. At times it has looked like the car without right of way not stopping. However our van with right of way caused a hesitation and emergency stop. If we were cycling there he v wouldn't have I'm certain.
During consultation stage we told them the single chicane would not do much. We said the only thing to slow cars would be speed bumps. Only the fear of damaging their speeding car would keep people to under the limit and only if there's a few along the road, proven right there.
My partner got worried by the speeding cars, bear in mind it's almost 100% of cars, so parked our old, big seat on the road. It basically created another chicane and slow spot. If every long run stretch had the odd car parked on the road it would slow traffic. It certainly did that by our house. Only trouble is we scrapped it a few weekends ago as we didn't use it and there's a water leak that meant we didn't like to drive it.
Councils know where their speeding problem areas are but budgets mean they don't want to spend to provide a working solution when a very cheap option will allow them to say they listened and responded to local concerns. Plus I suspect cars are king and they don't want to pee off the motorists. Can't slow them down.
As to the late night boy racers drag racing... well does anyone know how to build a homemade stinger?