The main reason I carry screwdrivers is to try and head off easily preventable problems - travel seems to loosen things you couldn't free at home!

OT: When I was cycle touring with a university group some er... decades... back, one person had a tyre blow out. Broke the wire in the rim bead. He proceeded to put in a new inner tube, inflated the tyre to about the right profile, then strapped the tyre and rim with about 50 small nylon cable ties. Put in some more air, disengaged the brake on that wheel, and led the group home. Great things, cable ties.