For a two-mile roundtrip, well-marked, well-travelled, popular trail as you describe -- in my region (DC, mid-Atlantic) -- the most important things I would carry are:
1) cell phone; 2) pepper spray
Out of habit and an abundance of caution, I'd probably take my hiking/bikejoring pack, which I use every weekend during fall-winter-spring and which presently includes: SOL survival poncho, AMK Heatsheet, blaze orange bandannas, first-aid kit, knife (currently Morakniv Garberg), titanium Sierra cup, "stormproof" matches, BIC lighter, firesteel/scraper, tinder, lip balm, small moleskine notebook, Sharpie marker, CCrane CC WX Pocket Radio, Petzl Zipka head/wrist lamp, compass (Suunto MC-2D), Garmin Foretrex 401 GPS, emergency (lightweight) dog slip-lead, 6' paracord. That pack also includes a couple breakfast bars.
Because I have incorporated "EDC" survival items into my routine, I'd have some important items simply by virtue of having my car key ring and house key lanyard with me, such as: firesteel, mini-prybar, small leatherman, Fox40 whistle, Fenix flashlight.
I've become of the opinion that on any outing beyond my side of town, I should be prepared to spend the night outdoors. So keeping dry, comfortable (warm during winter) and hydrated are my top priorities.
I always enjoy these discussions -- thanks, Hikermor.
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