Roger you are mixing up Speed Limits with safe/sensible/suitable driving speeds?
On Derestricted Roads the Maximum Legal speed for Single Carriageways is 60mph for Dual Carriageways the limit is 70.
This does not mean that you should travel at these speeds whilst travelling on them - you should drive according to the conditions, and at a speed that you can stop safely within the area you can see.
Other speed limits are brought in for safety reasons - decided by the local Highway Authority in consultation with the Police.
Lots of factors are taken into account including location ( most urban roads have a 30 limit for example), topography, accident record, traffic figures and typical speeds.
With regard to maintenance costs - the most expensive to maintain are Motorways due to their high standards - the cheapest are country roads which probably only need a surface dressing every 10 yrs? Most damage is caused by Heavy Goods Vehicles and PU's digging up the roads.
Junctions are generally treated with a high skid resistance expoxy surfacing.
Rod
On Derestricted Roads the Maximum Legal speed for Single Carriageways is 60mph for Dual Carriageways the limit is 70.
This does not mean that you should travel at these speeds whilst travelling on them - you should drive according to the conditions, and at a speed that you can stop safely within the area you can see.
Other speed limits are brought in for safety reasons - decided by the local Highway Authority in consultation with the Police.
Lots of factors are taken into account including location ( most urban roads have a 30 limit for example), topography, accident record, traffic figures and typical speeds.
With regard to maintenance costs - the most expensive to maintain are Motorways due to their high standards - the cheapest are country roads which probably only need a surface dressing every 10 yrs? Most damage is caused by Heavy Goods Vehicles and PU's digging up the roads.
Junctions are generally treated with a high skid resistance expoxy surfacing.
Rod