It's an issue with Waze's map editor security model. Concern with this security model has been expressed many times. It is what it is at this time. Be careful what you wish for, Waze may make it worse....
If you become an area manager you can override the locks. Another option is to work really hard to accumulate enough edits to equal or outrank the Wazer(s) who are locking the roads.
I am on mobile now so I can't unlock. I am sure someone will help you out shortly.
iPhone 5, iOS 6.1.4, Waze 3.6