Is it legal to change a 40mph limit to a 30mph limit without adding street lighting?

Question

It is my understanding tha a 30mph limit has to have street lights at a certain distance from each other. Is this correct, and if so, what is that distance?

Answer 1

Unless there are other signs there is a 30 limit wherever there are 10 or more street lamps to the mile; that counts as a "built up area". They don't put repeating signs for a 30 limit, just one at the start. Also a 30 limit doesn't need the street lamps, all it needs is a single 30 sign.
they shouldn't make large changes in the speed limit at one point. I thing a change of 20 mph is all that is permitted.
So a plain road has a speed limit of 70 for dual carriageway and Motorway, 60 for single carriageway UNLESS otherwise signed. With street lamps it is 30 ,again unless otherwise signed. That's why all the lights on motorways have "de-restriction" or speed limit signs on most lamp posts

Answer 2

It's the other way round I'm afraid. Lots of street lighting tends to indicate a 30mph limit, so they don't need much signage. If there are less street light making it less obvious its a 30mph then small speed limit repeater signs will be used.

Answer 3

No, if a street has this sort of town lighting and no indication of speed limit, it is set at the national limit of 30. It does not apply the other way round - a street can be designated at 30, but it will need reminder signs down it if it has no lights.

Answer 4

yes is the short answer. Reduction of speed limits to 30mph or introduction of 30mph speed limits can be a bit of a minefield, and the correct section of the relevant legislation needs to be used. Street lighting is not required to be provided by legislation, but it's provision in a derestricted area will in effect introduce a 30 mph limit in the absence of the imposition of another limit. e.eg rural junction improvenents including lighting. Limits can also be reduced puerly by the intrioduction of a reduced speed limit, but all limits below the derestricted norm for the designation/type for the road in question need repeater signs 30mph limits without streetlighting similarly require repeater signs (but they are not allowed where there is streetlighting. Hope you can follow this and it helps.

Answer 5

A 30 limit does not need street lamps. Street lamps closer than 200 metres on the other hand do impose a 30 limit or less, (it could be 20).

Answer 6

Of course it's legal. Street light placement has nothing to do with the speed limit.