I say "reasonable foot access" maybe any stretch with 5+ miles without any other access? Maximum distance between crossings would become 10 miles. Just spitballing and I'd have to map it out to see if that is reasonable. How do you feel about that distance?
I researched a similar issue due to the problem with the access I previously mentioned that I
had lost. What's reasonable-usable depends on:
Where would I park my car?
Where's the closest road that crosses the tracks?
Where are my favorite sections on the stream?
If the tracks parallel the stream (they often run along streams) can I walk along the stream without being within the RR right of way?
Is there a hiking-biking trail?
Is the property adjacent to the RR right of way private? posted? (if the access across the tracks generates traffic on private land, rest assured it
will be posted sooner than later.)
How far am I willing to walk-ride a bike?
Can I camp along the river?
How high-steep are the river bank along the tracks?
Along with that series of questions, how many trackside "points of interest" are along a line that the RR must provide pedestrian crossings for?
Will pedestrian traffic cause a risk of damage to the tracks and do crossings require more frequent track inspections and maintenance?
Does that increase costs for passengers and freight customers and what does that do to Customer retention?
It's not a simple problem.