Imagine that if at the grocery store the person bagging your purchases left empty, unused spaces in each bag causing you to carry 10 instead of 5 bags out to your car then into your home. You would be investing some extra time, energy and space when it was unnecessary. Now transfer that thought to the waste and recycling industry. Instead of filling a trash bag or bin with large empty spaces, we can all do some simple acts to help keep transportation costs down while reducing fossil fuel consumption and saving ourselves some time and money.
The flattening of boxes greatly increases space efficiency in a bin. This does not just apply to cardboard boxes, but also includes any paperboard (cereal or pet food) ones as well. Crushing cans before recycling is much more easily done if it is possible to remove both the top and bottom lids first. Foil products are easily flattened by hand.
Periodically crush your garbage bag down to its true size you will find that it does not need to be placed on the curb as often. Fewer trips to the dump means less fossil fuel consumed and reduced curbside idling idling is known to be terribly inefficient and more polluting than...