When you say "burm" is it a tar burm or dirt? Man, riding to work on dirt would be a drag everyday--
if there's room, you feel safe, and you're not creating a hazzard... you should be all set--
I'd be more worried about safety than the legality-- You say it's a 55 zone--- that means people are whizzing by at 65+ I'd be more worried about my life---~!
If there's a clearly marked "breakdown" lane, and its not a highway--go for it...I had to ride my moped home from the place I bought it on a route called "302" and it was zoned for 50 in parts--- it was scary as hell---but no police trouble...