Hi,
Some other stuff like ipchains & iptables has 'save' and 'restore' utilities that just take a snapshot of however the rules stand at that point. As far as I know, there is nothing comparable available for the routing table although it wouldn't be difficult to write something to do it. The only other thing is to make sure you always record all your route commands in a script and re-run that via /etc/rc.d/rc.local or equivalent at boot time.
Regards