Startup Idea : Share luggage allowance in airports

Ever had a lot of luggage and travelled with travelers who don't have as much? This is a very early stage idea but the intent is to have other travelers who do not have as much luggage to lend their remaining luggage allowance to other travelers. Not sure what the reward or incentive would be. Also unsure about the kind of security threats it could pose at airports or if people would feel unsafe sharing their allowance. Just wanted to brainstorm the various bugs/issues with this idea and if it could cause more problems than help people.