The UK has quite high speeds (125-140mph) on its conventional rail lines all on lines that were first built between 1850-1900 but have been gradually realigned

The UK has quite high speeds (125-140mph) on its conventional rail lines all on lines that were first built between 1850-1900 but have been gradually realigned to be faster. Most war damage was to the junctions not the route alignment out in open country so there were improvements in throughput at junctions made by rationalisation of the layout but routes between cities weren’t realigned because of war damage.