There are at least as many covers as there are finished manholes. Most manholes are already covered, and there are covers in stock ready to replace them, and covers in the factory ready to ship out. Unfinished manholes are relatively rare, but safety practices would probably require that random holes in a construction site should be covered by something. If you knew the proportion of unfinished manholes to stored and unused covers, you might be confident enough to boil it down to "There are at least as many covers as there are manholes."
My conservative estimate would be that there are a great many manhole covers on UK roads
Impossible to answer ! There is no 'register' of the location for every single manhole cover. Additionally, there could be many thousands on private properties.
200.0000
Typically in the UK, a house can be built as close as 3 meters to a manhole. However, local builders would be able to help you with the exact measurements for your area.
38 million, from 60 million citizens of whole UK.
1
The roads that the Tudors used were built by the Romans, and many roads that we have in the UK today, follow the same original foundations
0.1 percent of the area of the UK is covered by roads of one sort or another
A UK postcode only covers a small number of properties - for example the postcode for my own property also covers nine others.
There are many roads in the UK called London Road. As the name suggests, they were all originally roads that led to London.
Roman roads were used to convey horse-drawn chariots, other small wheeled vehicles. There are many remains in the UK, British Isles.
There were 31,035,791 motor vehicles on British roads in 2010. Source: SMMT
about 32 001 477 cars but not all vehicles
As of September 2015, there were 1,746,674 postcodes in use in the UK. Each postcode covers an average mean of 15 properties.