How can I set default parameter value in routing in rails 3

How can I set default parameter value in routing in Rails 3. For example I have this route

match ':slu开发者_运维问答g/:id/:direction' => 'quiz#show', :as => :quiz_details, :direction => "next"

and I want to default the value of direction to next.

---

match ':slug/:id/:direction' => 'quiz#show', :as => :quiz_details, :defaults => { :direction => "next" }

More details in the official Rails guides.