It looks as though your Index
route is never being hit, probably due to some other route defined before. Always keep your most specific route definitions first and leave the default Controller/Action/Id
to be defined last.
routes.MapRoute(
"Index",
"{controller}/{action}/{trip}/{year}",
new { controller = "Home", action = "Index" }
);
routes.MapRoute(
"Default",
"{controller}/{action}/{id}",
new { controller = "Default", action = "Index", id = UrlParameter.Optional }
);