We've been warned to brace ourselves for a partial strike on the Tube (subway) tomorrow, Christmas Eve.

The Picadilly Line, one of the most crucial lines in London, is expected to be hit by the strike. This will ball things up for travelers who depend on the line as a low-cost way to get into central London from Heathrow. The alternatives are the Heathrow Express, which is fast and efficient but more expensive; buses and cabs. Cabs are extremely expensive.

The whole system and buses will be shut down on Christmas Day. But that's not a strike. That's normal. As a long-time New Yorker, I still have a hard time comprehending the shutdown of a transit system in a major city. The New York system never shuts down, aside from the occasional blackout.