So, if the 8 billion people on Earth each walk 5 miles per day, that's an aggregate 2.5 lightyears/year of travel. Actual values may vary, but within an order

So, if the 8 billion people on Earth each walk 5 miles per day, that's an aggregate 2.5 lightyears/year of travel. Actual values may vary, but within an order of magnitude, humans collectively do probably walk about a lightyear per year or so.