On Wed, 07 Apr 2021 09:43:38 +0700, John B.
wrote:

I'm not any sort of Civil Engineer but I worked for a while with a guy
that built roads for a living and according to him the underlying
foundation is the most important part of a road, particularly allowing
for water drainage. He also said that these design criteria have been
know since the days when the Romans were building roads :-)

I read somewhere that the underlying foundation *was* the road, and
the concrete or asphalt on top was just a raincoat.

--
Joy Beeson
joy beeson at centurylink dot net
http://wlweather.net/PAGEJOY/