I'm not your target market because I don't run at night, but you have a niche.
I think, and you can correct me if I'm wrong, that moving lights grab attention much better than a relatively stationary light (i.e., a headlamp). It would provide extra visibility when crossing intersections, for example, when reflective vests might not be as visible as they normally are.
Around the big university near me, I see women running in low light/dark conditions with earphones who seem oblivious to what's going on around them. This should be one of your primary markets. Just making them more visible crossing intersections would be a big selling point, but you would have to market that feature to them. Buyers won't see the benefits of your product if you don't point them out.
You need to figure out how to market this.
How else could a runner use the GPS or the alarm, for example?
Me: "I'm going out for 12 miles. If my knee acts up, I'll hit the GPS and start walking back. Come and pick me up, okay?"
More than once, I've wound up miles from home and had to walk back. It took forever. Could your device do that? If so, that's another feature you need to market to your prospective customer. Anyway, that's my suggestion. Good luck.
Oh, and you need to get in touch with the Ragnar and Hood to Coast Relay folks. Their participants are also your target market.