Hi Dave,
Good points there, however, technically speeking the A17 has been upgraded in the past forty years. When I first drove down the A17 you went through all the villages like Long Sutton etc. A length of road I thought would never reach Kings Lynn after seven hours then. (the A66 was rubbish then also) The mistake they made IMHO they didn't make it a proper dual carriageway from Sleeford to Kings Lynn. Probably the government of the day could not afford it, or would have been held to ransom maybe from the farming community down the full length of that road, for the additional land.
Iain.