I closed some route but didn't check the "Release slots" checkbox. How can I release them now, in order to use them? Thanks.
If you release them you have pay again for them.
To use your unused slots just plan a new route and if the times are close to the times of the unused slots the system uses them automatically (price 0).
And if you want to release them, you can re-create the same route wth the same times (you won't pay a dime), and then close it and check release slots.
Thanks! :-)