It is now possible to put a slash within parenthesis as an optional part of the route:
var Router = Backbone.Router.extend({
routes: {
'order/:orderNumber/:stepName(/)': 'getOrder'
},
// ...
});
From a pretty comprehensive issue thread on the topic of slashes at the end of Backbone routes.
But as also noted in that thread, to prevent multiple URLs being recorded for your pages it's best to remove the slash at the end of paths in Apache or other server configuration.