"All street types require "sidewalks". This means pedestrians may path along the side of the light rail tracks"

I believe that is only true for local roads, roads where houses might pop up.

The rural roads doesn't allow buildings. Normally the town will automatically convert them into local roads as the town expands, but if you can prevent this, perhaps using rural roads as your starting point would be better - no roads, pavements or streetwalkers along that kind of light rail?