Submit permalinks with pertinent segments for correction to the Unlock Request subforum in Editing. Make the changes and then relock it and save (assuming it's a high-value roadway) so you can access it later.
It's a pain in the butt, but it's the only way. I am in a similar situation.
P.S. If you have the capacity to travel someplace where there aren't other editors, you can earn a lot of points that way. I'm in Hawaii where opportunities are limited but took Waze on vacation to an area in Washington state to visit my daughter in college. The place was wide open, and full of easily correctible errors. (I know the town somewhat but in general stuck with making non-navigational edits -- alignment, eliminating connectivity errors and such.)
Oahu, Kauai and Lanai, Hawaii
iPhone4, iOS 6.1.2