ASP。净MVC System.Web.Routing。RouteCollection模棱两可的参考吗?

I am trying to write a unit test for testing routes; however, the project is failing to resolve the RouteCollection. When I reference the dll (from the system and also by browsing to my MVC project) and use the FQN (System.Web.Routing.RouteCollection), it complains of an ambiguous reference.I am trying to write a unit test for testing ro