Bridge question has been answered, here's route question response.
The drive you have planned is a wonderful drive. CO 17 up the San Luis Valley is very straight, but interesting (IMO), as one gets to see the transition from high desert to mountain valley very subtly.
Up and over Poncha Pass, not a difficult pass at all; a bit curvy on the way down the north side of the pass, but it's a good 3 lane road. US 50 from Salida runs along the Arkansas River, and there's a goodly amount of twisties there, but it's not difficult at all, just take your time as you would with any type of canyon driving. Once you get out in the flats and the intersection with CO 115, it's smooth sailing all the way to the Springs, very scenic drive. Interesting sidebar - a LOT of the land on the east side of CO 115 is part of Fort Carson Military Base. It's a huge facility.