One more comment...having laid a jillion flare patters in my career, I am here to tell you that drivers WILL run over at least some of your flares. If they are expensive re-usable electronic types, you just lost them for good...with the normal burning flares, remember to look for puddles of gas before you light one, and watch for wind, dry grass, etc...and remember, most drivers are driving HUA, so you've gotta start a flare pattern way way way down the road to give them time to see, think, and react...