There is a pedestrian bridge over the highway at the summit

I don't see (on streetview) any clearance warning signs. But there's a large reststop and view point 0.2mile before this. Stop, taking the views, and hike up to the bridge for more views. I'd suggest driving this pass in the morning (or early afternoon) to have the sun for views. With the right sun, some of the best views of Mt Rainier can be had from this pass.
This is a streetview of the tightest curve (on the west side of the pass) (150' radius - same as a freeway cloverleaf). There is only one set of switchbacks, and the curvatures are not exceptional.
https://maps.google.com/?ll=46.868495,-121.537113&spn=0.007144,0.018346&t=m&z=16&layer=c&cbll=46.868596,-121.537122&panoid=FtqHeEJQkmaW8MQXSTBDjg&cbp=12,357.38,,0,6