I am employed full-time as a web application developer for a Fortune 500 company and my salary equates to about $32/hour (plus benefits). This includes web app development in ASP/ASP.NET and JSP, database management and server maintainance as well as interface design using XHTML/DHTML.
I also do freelance work for e-commerce sites where I charge $40/hour for design/coding/DB/flash/etc. The work is similar to my full-time job. I am located in New Orleans, LA. I have been doing freelance web work for almost six years. My work is above average.
I think charging over $80/hour for web design only (no programming/DB) is absurd. Perhaps visual/interface designers who are in extremely high demand can demand such rates in big cities, but this is not 1998 and most people will not pay that much. Freelancers in New Orleans are largely quite untalented, ignorant of coding standards, and apparently colorblind, but they will charge some Mom&Pop store $80/hour to put up an ugly-ass homepage WYSIWYG'ed in FrontPage. The store owner's don't know any better because they know nothing about the internet, nor going rates. Congratulations, you just ripped someone off.
Plumbers may charge $90/hour, but he probably won't spend more than 2 hours at your house and HE HAS TO HANDLE YOUR POO. Hello, health hazard. Car mechanics are generally experienced and they are greasy as heck and are putting themselves inside a huge machine. As a web designer, the most physically taxing thing you will ever have to do is adjust your monitor. Oh, and watch out for carpal tunnel, you wuss.
There are no real web design schools, so your education won't tell a potential client that you are prepared or worth the money (although a graphic arts/design degree might help). I guess my point is: Don't come out of the gate charging these rates. Start modestly and build a portfolio. Observe web standards.