The lack of sidewalks throughout all of suburban Massachusetts (but especially the Cape) is honestly baffling. I don't understand why building new sidewalks isn't a bigger priority. I hear people complain about the lack of sidewalks in my area (MetroWest) all the time, but nothing ever really comes of it. I've been advocating for a sidewalk on my street for the past couple of years (I even started a petition), and my town is in the initial stages of evaluating the feasibility of building a sidewalk. But I really don't understand why it's taken until 2025 just for them to start looking into building a sidewalk here. Around 20 years ago, an elderly pedestrian got hit and killed by a drunk driver on my street, but even that wasn't enough for my town to put in a sidewalk. Most suburban towns in Eastern Massachusetts should have spent the past 40-50 years building out a complete sidewalk network.
Trees and front yard configurations in general.
It's easy to shove a sidewalk into your average modern subdivision even after the fact - with an average recent subdivision, front yards are mostly a sea of empty lawn. If you didn't build sidewalks up front, not such a big deal to add them later.
In MA you've often got dense, mature trees lining a narrow road or significant homeowner landscaping/fence/rock wall right up to it, high odds of having all the utility poles sitting right where you want to put the sidewalk and needing to be moved, etc. And a decent portion of homes, especially in the oldest areas, sitting very close to the existing road.
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I lived in a town in NJ that investigated putting in a sidewalk on a road of similar description to many of MA's. (Narrow road that dates to the colonial era and so do a couple of the homes, most of the rest 1800s-1950). Conceptually, everyone agrees that a sidewalk would be a good idea.
But the initial result for like one mile of sidewalk, even if no one actually sued, was going to be an absurd # of tree removals, having to relocate a bunch of power poles, a bunch of yards that really would be wrecked, and at least one house very close to the road that would lose all it's screening vegetation and go from being mostly invisible to having people walking 3ft from the windows.
As you may guess, it was tabled after that - both for the cost estimate that was
many times what you'd expect and how poorly it was expected to go over with the community.
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Edit: And I forgot something massive -
drainage! Many of these roads don't actually have stormwater systems in place now or only have them in the low/worst spots. Most water just runs off into the dirt wherever. Sidewalks mean curbs, curbs mean you now need to do full storm drains on the entire road. That's also a big part of the $$$$. Now you're talking total road reconstruction. Maybe you can get away without if you only do single-sided sidewalks on the uphill side of a road with a consistent grade (where runoff always went to the downhill side and still can), but that's not most roads.