That seems like the distance to go from having 100k people in front of you to having 100k people behind you. The distance you'd have to go to run into them properly would depend critically on the width of the vehicle you're in. With about 30k people running the Boston marathon and 60k people running the NY marathon, if you can source a vehicle wide enough to cover the course, it seems like you could pull it off in just a bit over 52.4 miles... assuming that the bodies didn't produce enough drag to slow you down so much that runners were managing to stay ahead of you on the course. (And assuming that marathon runners prioritize completion of the course over running sideways away from obvious danger, but they're marathon runners, that seems like a safe assumption.)

> That seems like the distance to go from having 100k people in front of you to having 100k people behind you

0 metres. Just turn round.

To pass within say 5m of someone you just need to set up shop at a busy train platform and wait. With 1000 people passing every 2 minutes it won’t take long to pass 100k (well presumably about 3 hours)

Ah interesting, I seen the title "run into" as "bump into" or in this context, get to where 100k people are. I don't know any US addresses far from population centers so I pumped in Area 51!

Clarity needed on the title or description!