The feed zone rule in cycling is enforced by mood

Riders may only take food in marked sections, except when they may not, and the sticky bottle sits somewhere in between.

A rider drifts back to the team car, takes a bidon, and holds it a beat too long while the car pulls him up the road. Everyone watching knows what happened. The commissaire knows too. Most days, nothing follows.

Feeding regulations in road racing are unusually detailed. Designated zones, distances from the finish where feeding stops, rules on where a rider may collect from a car, prohibitions on receiving anything on descents or in the closing kilometres. The reasoning is a mix of safety and fairness: bottles bouncing across a peloton cause crashes, litter angers host towns, and a rider towed back into a group by a car has been given an advantage the others did not get.

In practice the enforcement is graduated in an unwritten way that no rulebook describes. Sticky bottles are tolerated up to about the point where they become obvious, and the trigger for a fine is usually visibility rather than magnitude. Cameras change behaviour more reliably than the regulation does, and everyone in the convoy knows which parts of a stage are televised.

Where the rule bites hard is at the other end. Feeding inside the final kilometres is genuinely policed, because it is easy to see and easy to prove, and it is also the moment when a depleted rider most needs a gel. So the regulation is at its strictest exactly where the nutritional argument for flexibility is strongest, not because anyone weighed those things against each other, but because that section is where officials can watch.

Litter penalties have gone the same way. Discarding a bottle outside a designated area now carries a real sanction, which was overdue given what the roadsides looked like, and the effect on riders is that a bidon becomes something you carry rather than something you use freely.

I would trade the whole tangle for a simpler rule: feeding permitted anywhere it is safe, litter enforced ruthlessly, and vehicle contact timed by transponder rather than judged by eye. Fairness is measurable. Tolerance applied by feel is not fairness, it is a favour, and favours in bike racing have a way of following the same teams.