Arguing and pleading with security personnel or airline staff at the boarding gate will get you nowhere if you’re running late at Heathrow. Because your complaint won’t even fall on deaf ears. The new automated gates at terminals 1 and 3 (soon terminal 4 as well) can bar passengers arriving late, while giving the carrier a heads-up to remove his or her luggage. The ‘positive boarding’ technology reads bar codes on boarding passes to prevent flight delays, yes, but is also kind enough to give you notice when you’re cutting it close and ensures you aren’t parted from your baggage in haste.