Missing 1/2 of an itinerary

I’m presently trying to book a trip by major air carrier comprised of two flights each way (Points A to B to C). There’s a chance I may not be able to make it to the airport during the first leg of the trip (Point A). I will have enough notice to drive the missed, short-distance first leg, making the total trip driving from Point A to Point B, catching the second flight from Point B to Point C.

Is is possible to check in at Point B’s airport without penalty even though my overall itinerary has me going from Point A?

In short, no.
The entire itinerary is void if you miss the first leg. The airline’s view is that if you did not fly from A to B then you cannot be in town B. Therefore the rest of the itinerary is worthless. (yes I know that some towns are within in driving distance, but the airlines aparently don’t)
Ask me how I know this. :smack:

What you’d be accidentally attempting is what’s called a hidden city discount.

The usual scenario is along the lines of: You live in San Francisco. A fare from San Francisco to Chicago is $400. The fare from Los Angeles to Chicago, connecting in San Francisco is $300. If you book the cheaper fare and attempt to check in at SF, the whole itinerary is void because you did not start at the actual start of the flight.

It may still be possible to book a one-way flight for the return and do this as long as you have no checked bags. It was fairly common for people to book something like Chicago to LA, connecting in SF, and just leave at SF. With the use of enormous computerized databases and something called a PNR or Passenger Name Record, the airlines can easily flag passengers that do this now.