Whoa. Don't like heights? Don't look outside the car then! This road is only drivable one way and starts off on the flat but you soon find yourself ascending the side of the valley, climbing up and up on narrow dirt roads whilst navigating tight switchbacks (and I mean tight, several large 4x4's couldn't make it round them in one swing). The views over the edge are amazing and there's even a few places to pull off and hike a short trail or just take in the view. Be warned that this is not a road you can drive fast and while a 4x4 is not really necessary it sure does help with the ride. If you're doing 15mph on here you're going fast. The road eventually reaches the Alpine Meadow Visitor centre at the summit where a plethora of souvenirs gifts and overpriced food await you, as do simply stunning views of the alpine valley you just drove up the side of. We were in a steady snake of traffic on the way up and it was nice to get out, stretch our legs and then continue on to the paved Trail Ridge Road.