Have you read my treatise on routes in the Wiki (
http://wiki.bots-united.com/index.php/The_Route_System)?
The way I check out each and every route in my maps is to set the probability of a single path to 100% to force a bot to go that way and no other way. Then I follow him and see if he does go where I intended. If not, time to troubleshoot. If all paths work OK, then I run a large number of bots on a given route node and check that the path probabilities are correct. Since they choose alt_roams randomly, you should run at least 100 bot iterations to get a meaningful measure of the probabilities.
Let us know exactly what happens if the wiki article doesn't help.