Yes, they'd have to re-direct traffic. Indeed, in this instance anyone wanting to enter Winifred from southbound Buena Vista or eastbound Belvedere had to continue south on Buena Vista and go all the way around the Rainey Trail circle. Not a big deal.
But, if the accident had blocked the entrance to Winifred, then there'd have been some inconvenienced folks, as there's no other way in!
SWR
