I'm trying to find out how the name High Street and Highway came about and I have found two conflicting meanings of high.
One is that it comes from Roman roads as they were built higher than their surroundings.
"The word highway goes back to the elevated Roman roads that had a mound or hill formed by earth from the side ditches thrown toward the centre, thus high way."
https://www.britannica.com/technology/road
http://www.surveyhistory.org/how_the_road_got_its_name1.htm
And the other is that it comes from high meaning principle, as in the main street.
"The name seems to have emerged in the 12th century when the word ‘high’ began to be used to indicate something or someone of a higher, or more important, status than others."
http://www.historyextra.com/qa/high-street
http://www.wordorigins.org/index.php/more/1645/
http://www.etymonline.com/index.php?term=highway
Which of these origins is correct?