Yay for you!!!!

I would try each route on the weekend, and get to know it well. Know which one is scariest for traffic, which one takes the longest, which one will get funky in the funky weather, and then any given day you can make your decision. I have a long route and 2 short routes; the shortest is on busier streets but if it's early it's not a problem.
Does the parkway get a lot of commuter/rush hour traffic or do most cars keep to town? If there isn't much traffic that's where I"d lean towards but the windiness and narrowness are real disadvantages when having to coexist with cars. (I'm feeling all sensitive 'cause I just went to a "bicycle treatment" seminar and listened to the highway engineers discuss it.)