The rock slides in fall in the canyon can be a problem. Also being in the canyon it will be shadows very early. If it was me I would just park at the Glenwood depot. Traffic at most will be 1 an hour. Early fall in the rockies has wet weather than a freeze at night this causes boulders to come off the steep mtn sides. The catch fences do a good job but every year large ones destroy whole lanes and take months to fix. Glenwood is a huge problem for driving. Don't take this the wrong way but if you are a flatlander just stay in the slow lane and don't drive over your head. People who have driven these roads all there lifes will drive much faster than what you can. Every year CSP peals the flatlanders off the side of the mtn. they try to go as fast as the locals but lose it on an ice patch and poof granite don't give. Good luck