For route based tunnel failover you are best to use a dynamic protocol instead of static routes. Static routes will remain active in the route table as long as the next hop interface is up. And by default these tunnel interfaces stay up even when vpn connectivity goes down.
By using a dynamic profile you avoid this problem because the routes will be lost when the neighbor is lost due to the tunnel going down and your failover can kick in.
Steve Puluka BSEET - Juniper Ambassador IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP) http://puluka.com/home