Do you mean 40 or 50 MPH up your street? Is your street a 30 limit? If so, what makes you think the drivers who do 40 ad 50 up there are going to pay any more attention to a 20 limit than to a 30 limit?
No, it is a 20 limit. I don't think they do that, I know they do that. I am on the outside of a bend in the street, an accurate, straight 100 yards to another bend, then 100 yards the other way to the end. Which means I can watch and time them over the distance, from which I can calculate the speed.
Those drivers tend to be the exceptions, the younger drivers showing off for the little girls - more usually it is below 35. It is particularly busy at the moment, because an almost parallel main road is closed, because they are working on the single lane bridge over the railway. Yesterday, there were four cars trundling along at 20 behind a lead car, a behaving themselves, then an idiot in a black Audi came up behind them, just as the lead car came up behind a skip, close to the next bend. Idiot in Audi decided it was just fine to overtake the lot - luckily the lead driver looked in his mirror and was able to stop before hitting the skip. Audi on wrong side of the road, on the bend, then faced a bin lorry coming other way. The quick thinking bin lorry driver, went up on the footpath to avoid the Audi.
I see such incidents all the time. I don't spend my life watching, I only glance out if I hear an incident, or when in the front bedroom getting changed. I seen quite a few minor accidents over the years, when just glancing out, so I have likely missed many. I saw a young lad knocked of his bike by a car going one way and about to pass him, when a speeding car came tearing along the opposite way. I saw a weaving drunken driver late at night drive into a neighbours car on the wrong side of his road. The almost new neighbours car was written off, pushed over the footpath and into a gate post - the drunken driver managed to just reverse and drive off without stopping. The neighbours reaction, once I had knocked at their door to tell them, was to shrug and just say never mind it's insured.
I think a part of the problem is that we live within driving range of a large city. At one time our pubs would have later closing than in the city, so it gained a reputation as place to go, where there are few police and little policing. It's not so wild as it used to be on Friday and Saturday nights, but the 'little policing' does seem to have stuck.
The original police presence was a sergeant in a police house. Then they built a tiny police station with lots of parking and storage space. The station closed, but with the building of a new motorway 1.5 miles away, they turned it into a depot for traffic policing and firearms. It's an upmarket, very low crime area, so we rarely see any policing all, unless they get lost.
Our nearest manned police station is now the far side of the city, some 15 20 miles away.