My own interest here is that systems like this should include routes that don't fit into our comprehensive systems but for which TM users would most likely be interested in mapping their travels. I'm opposed to the rigid rules we inherited from CHM, but developing an updated set of guidelines to help decide what should qualify would be useful. There is the matter of finding the balance between wanting to include anything someone wants with trying not to annoy those who see very minor additions as clutter.
I think the issue on the negative side is more than simply a matter of "clutter".
From my perspective, the issue is thus: like with anything else which can be collected, routes form a "set" which at least some collectors will seek to complete. Whether a particular route should be included, therefore, needs to be evaluated not just on its own individual merit, but also in the context of whether collecting it should be considered necessary to complete the "set".
This is the biggest reason why I am generally defensive regarding additions of more roads to usasf, and why I've also been a critic of other systems that have been added outside the normal trinity of Interstate/US/state routes. By adding these extra things, we are not just providing users with more routes they
can clinch- we're also making it such that if someone wants their stats for a state to show 100%, there are more routes they
must clinch.
This is especially problematic when you consider the game has already been ongoing for quite some time. I myself have 100% clinches of four states, and for all of them I used what was in CHM/TM as a checklist to determine what I did and did not need to clinch. I would not appreciate losing one of these 100% clinches because someone decided to move the goalposts ex post facto.