As for keeping up with maintenance, well, that's just criminal while overcharging motorists £25b a year, no?
As for the initial cost, that's harder to figure out, but this (dodgy looking, admittedly) website[1] suggests that a mile of motorway costs £24m to construct. That means that the motorists are "paying off" the roads at a rate of about 1000 miles a year. There are 7500 miles of motorwayways and A roads[2], but motorists have been paying more in taxes than has been spent directly, although not at the current rate, for 30 years, and with no sign of slowing down.
As for the initial cost, that's harder to figure out, but this (dodgy looking, admittedly) website[1] suggests that a mile of motorway costs £24m to construct. That means that the motorists are "paying off" the roads at a rate of about 1000 miles a year. There are 7500 miles of motorwayways and A roads[2], but motorists have been paying more in taxes than has been spent directly, although not at the current rate, for 30 years, and with no sign of slowing down.
1: https://63336.com/brilliant_answers/2009/06/how_much_does_it...
2: https://www.gov.uk/government/publications/road-lengths-stat...