Can somebody please explain why our speed limits go up and down in level 10s?

Looking sur la continent I see they have a little more imagination and have multiples of 5 in may cases, ie (kph) 45, 75, 95 have been spotted by me in Portugal.

Is it that all our speed limit people are dyed in the wool, have a stock of 1 million "0"s to get rid of or just unimaginative?

Neil

It does seem strange when one considers the Dickensian mentality of the road traffic authorities. One would of thought that they may consider rounding up in dozens.

theoldman wrote: ↑Sun Oct 15, 2017 8:37 pm Can somebody please explain why our speed limits go up and down in level 10s?

Neil

It could be because speedometers usually show numbers ending in 0. It can take more than a quick glance to tell whether the needle is at 45 when the nearest numbers are 30 and 50.

I am surprised that we don't have them going up in dozens or even sevens, just to be awkward. If we tried to be more European we could covert exactly to KM/H with really confusing numbers, decimal places and even fractions.

Neil, the law requires speedometers to be marked at intervals of 10mph. I remember reading somewhere that it was judged that motorists would not be able to discern intermediate limits and so speed limits were set to match the speedometer intervals.
Most European speed limits (France, Germany, Italy, Netherlands, Belgium, Luxembourg, Czech Republic, Scandinavian countries) that I know of also change by 10kmh intervals, i.e. 30kmh (18mph) in town centres.