In reading through this article:

In Subfolder & File Names, Use Dashes, Not Underscores Good:

Good: http://www.domain.com/sub-folder/file-name.htm

Bad: http://www.domain.com/sub_folder/file_name.htm

In my URL's, I may have one or two city names, ending with the province/state: Burnaby_New_Westminister-BC/[some search term].

My URL rules currently are defined such that everything after the dash is the prov/state.

Some geographic locations already contain dashes: Notre-Dame-de-Grâce (in QC), which I would convert to ~/Notre_Dame_de_Grace-QC/

I thought of placing the prov/state after another "/", however in some cases the province/state name may not exist, thus ~/Notre_Dame_de_Grace/, so the first term after the domain name contains the geo location {city, city_name-state}.

I am now revisiting this, and wondering if this rule set should change, and if so, what is the recommended way of implementing this?

-- UPDATE --

After reviewing this video, I see that I should be using the dashes, rather than underscores. However since I still want to have my geo locations in the first URL section, is there anything wrong with using a double-dash separator - ie: /city-name--state/ ?