How to prevent Rails from url-encoding

I have a route
map.connect 'browse/:languages', :controller => 'browse', :action => 'index'
where I expect :languages to be something like 'en+jp+zh_tw' so that I can later do
languages = params[:languages].split(' ')
(because + is an equivalent of a space in a url). But Rails does url-encode all params, and I get 'en%2Bjp%2Bzh_tw'.
Of course, I could .split('%2B'), but the url is getting so ugly!
Is there a method to prevent Rails from url-encoding in this case?

/Damian

I got with the problem by joining languages by a space instead of a plus sign. It then becomes a nice + in a url.
Sorry for disturbance.