Merging Routes?

I really want to merge the Avery route with the UMR and Indiana route, but I haven't figured out how to join them up. Any tips?

EDIT: I know how to merge, but finding a way of joining two or more routes up is tricky.

Hi you can merge route, but i guess u may face altitude prob for sure , becoz when i try to join another route i got this prob so i placed 6 boards to match height diff, but u can use transdem to adjustht diff , but transdem is payware.