Enumerating .NET MVC RouteTable Route URLs?

I'm trying to figure out how to enumerate the URLs of Routes in the RouteTable.In my scenario, I have the following routes defined:

routes.MapRoute
("PadCreateNote", "create", new { controller = "Pad", action = "CreateNote" });
routes.MapRoute [code]...

In other words, if my site is mysite.com, mysite.com/create invokes PadController.CreateNote(), and mysite.com/foobaris invokes PadController.Index().I also have a class that strongly types usernames:

public class Username
{
public readonly string value;[code]....

In the constructor for Username, I would like to check to make sure that name isn't a defined route. For example, if this is called:

var username = new Username("create");

Then an exception should be thrown. What do I need to replace //... make sure 'name' isn't a route URL off root with?