I think there is a little misunderstanding.
As I mentioned in this post:
A route is not sent to a device that is assigned to it. You can send a set of route stops to a device by sending a set of TextMessages (RouteMessages) to that Device.
Also note the Distinction between a Route and a Route Plan. You can see these in MyGeotab under Zones & Messages -> Routes... -> Routes. Notice, under options at the top of the page you can search for Routes or Route Plans. The distinction being, a Route is a set of waypoints where a Route Plan is a Route that has certain expectations, like time, distance, etc for a Device. Create a route and route plan in MyGeotab and the differences will become more clear.