One of the quieter issues about walkability is the overgrowth of plants and trees into the footpath. This either narrows the footpath itself, or, if elevated, the walking path, leading one to walk into branches and bushes, or scoot over to avoid them.
The footpath is normally treated as a two-dimensional object. That it is called a “footpath” rather than a “sidewalk”, as in countries where English is spoken properly, assists in the confusion. It is not simply a 2-dimensional object where the bottom of one’s feet hits a planar pavement. It is a three-dimensional path where a body moves through space.
Given the range in human bodies, it needs to be sized to accomodate all, or nearly all, of them, say 3 m given human heights and a child upon their shoulder or goods being carried. We need to think about a walking space, as shown in the figure, not simply a footpath in our designs. And we need to ensure that such spaces are cleared of overgrowth as lovely as it might be, as well as signs and other needless invaders of walking space, so long as we are mostly taller than Hobbits.
This of course does not require chopping down trees, merely trimming, to reduce low level branches, the way the herbivores that used to roam the land that is now our streets might have done naturally.