Using MvcCodeRouting with the default setup will correctly generate routes and @Html.ActionLink etc all generate the correct Url.
However if you are using another tool to generate the Urls such as MvcSiteMap (https://github.com/maartenba/MvcSiteMapProvider) or MvcRouteTester (https://github.com/AnthonySteele/MvcRouteTester) then it is generating null routes.
This seems to be a breaking change between version 1.0.0 and 1.0.1 - when stepping through the source it seems to ultimately be in ICodeRoute.cs approx line 112
if (requestRouteDataTokens.ContainsKey(DataTokenKeys.RouteContext))
routeContext = (string)requestRouteDataTokens[DataTokenKeys.RouteContext];
if (routeContext == null)
return null;
as routeContext is seemingly coming back as null when called from these other tools.