[thorpie]

It almost sounds like you are advocating a different grade coming into town than leaving. That can't be right, can it?

There are two gradients. For the bulk of travel it is downhill at 0.7%. The uphill elevation shift gradient, while not "standardized" at this time, will be considerably steeper than the 0.7% downhill. If the uphill is 7% then 91% of travel will be on the 0.7% gradient and only 9% on the uphill elevation shift. At this time the uphill gradient is undefined because it needs to cater for a variety of different engine powers.
Because town centres are most often besides water, which is at the low point of surrounding areas, then coming into town the terrain will often naturally provide a 0.7% downhill gradient with no uphill elevation shifts. In these cases travelling out of town will require double the elevation shift, so only 82% of travel will be on 0.7% downhill while 18% will be on 7% uphill.

While you don't mention a limitation, you must not be discussing mountainous terrain. I know of some roads where it would take 30 miles of approach road building @0.7% just to get to where the road starts up the mountain. Surely you didn't mean that, did you?

This is 30 miles of downhill assistance that is currently not utilized. 30 miles @ 0.7% is 1,100 ft. Travelling towards the mountain would be 3 miles of elevation shift @ 7% for the 1,100 ft elevation increase plus a further 2.7 miles for the elevation shift to provide for 0.7% travel on the bulk. So there would be 5.7 miles @ 7% uphill & 24.3 miles @ 0.7% downhill.

You seem to imply a connection between mass production and road building. I am under the impression that roads can not be mass produced - that they are built "in situ", that is, in place. What am I missing here?

Here you have hit the crux. I am precisely saying that for long term it is better to mass produce the roads and infrastructure to a standardized form. Long term being what we leave our kids and grandkids. Leaving our kids the current non-standardized road network, which we value at so many trillions of dollars, is likely to be worth nothing to them. Zilch! Here you go kids, we leave you a hindrance, the 20th century folly.