Having just read the comments on the FP article about John Oliver and his fuck barrel I decided to share with you the grounds for prosecution regarding speeding in the UK. Let me know how where you live compares.
First things first. If you are speeding in the UK, you don't automatically get a ticket. The Association of Chief Police Officers (ACPO) has issued speed enforcement policy guidance, which suggests that enforcement will normally occur when a driver exceeds the speed limit by a particular margin. This is normally 10 per cent over the speed limit plus 2 mph. It also sets guidelines for when it would not be appropriate to issue a fixed penalty notice but to issue a court summons instead (see below). Note that these are guidelines and that a police officer has discretion to act outside of them providing he acts fairly, consistently and proportionately.
Speed limit: 20 mph
ACPO charging threshold: 24 mph
Summons: 35 mph
Speed limit: 30 mph
ACPO charging threshold: 35 mph
Summons: 50 mph
Speed limit: 40 mph
ACPO charging threshold: 46 mph
Summons: 66 mph
Speed limit: 50 mph
ACPO charging threshold: 57 mph
Summons: 76 mph
Speed limit: 60 mph
ACPO charging threshold: 68 mph
Summons: 86 mph
Speed limit: 70 mph
ACPO charging threshold: 79 mph
Summons: 96 mph
So I can creep over the limit without concern. it is however worth noting that in the UK it is not cops on the side of the road that catch you most, it's cameras. The cameras are usually sign posted and covered in a yellow reflective coating so if you get caught by one you are just unlucky but still people do caught, every day. Recently other less overt types of camera have appeared on motorways and are causing a fuss in the media as more and more inattentive drivers are caught breaking the law.
Another breed of camera used to enforce speeds are the average speed cameras that time you point to point and calculate your average speed. These are used typically when lengthy road work is being undertaken to protect workers (though the limit is fixed even when no workers are present. I believe these adhere to the ACPO thresholds but I've never been caught by one, so I don't know.
The issue with enforcement by camera is that there is no discretion involved, the camera never cuts you a break. You can appeal but you probably can't get out of it. To date, I've never been prosecuted for a motoring offence but I have had run ins with the police, One of these was regarding my speed. One rainy night, I had just dropped a friend home from the pub and was pulling out on to a main road as I normally would (not slowly, but not like a maniac) and continue down this 30mph road at about 30-35. I look in my rearview and see some headlights in the distance approaching rapidly, they get reasonably close then flick on the blue lights. I pull over quickly and safely, I was told I exited a corner too quickly and sped away at "over 40", as I was out at night a young man and they thought I was driving poorly, the next question was "where have you come from?" to which I replied "the pub". They quickly produced a breathalyser and I provided a breath test and I made small talk with them (two ladies) and the result came back as a zero (I'm practically tee total anyway) and I was allowed on my way with no ticket. Discretion is nice because if you ain't an ass you'll get cut a break.
If you get a ticket you will not only receive a fine, but also penalty points on your licence. in the UK a driver is permitted to accrue 12 points on their licence before losing it for a period of time (begins with a six month ban) and the severity of speeding offences dictate how many points are given. for low level speeding offences it is 3 points with a £100 fine, if you are a first time offender you also have the option to forgo the points and pay a similar amount to go to a police run "speed awareness course" this is appealing as the points will increase your insurance premiums. As speed increases points and fines do too up to a maximum of 6 points and £2500. If you don't pay the fine, you'll go to court and be made to pay, if it's difficult for you to pay the court will work out a payment plan with you.
Points are also given if your tires are defective or you don't have insurance. So if say for example you have a bald tyre, no insurance and get pulled over doing 40 in a 30, you could be banned from driving for six months. Another fact that might surprise you is that not all police cars in the the UK carry speed recording equipment, A local area car will likely be a low powered hatch and it isn't deemed necessary for them to carry speed equipment and it is typically reserved for traffic cars like Jags, BMW, Audi, Mercedes and Skodas.
So, I ask how does this compare to your locale?