permitted_uri_chars with slash

encodeURIComponent("Collinsfield street 5/a") will give "Collinsfield%20street%205%2Fa", which should be valid.
But since '/' is an URI separator, maybe it cause confusion even if you use encodeURIComponent() to translate it to "%2F".

My guess is CodeIgniter convert it back to / and look for a route that doesn't exists. You should probably use '-' instead of '/' to avoid this.