Can I see one example that would make this piece of code compile?

    public IEnumerable<RouteBase> Routes
    {
        get
        {
            return new List<Route>()
            {
                new Route(...)
            }
        }
    }

What would you do if RouteCollection.MapRoute() didn't exist?

I'm trying to put my Controller in charge of mapping routes, not Global.asax.cs. public IEnumerable<RouteBase> Routes is a member of my Controller. If the Controller is responsible for a Route, it's a bad idea to decouple the Route by using routes.MapRoute() in Global.asax.cs.