Personally I'd love to take more trains instead of planes, and bike more instead of driving, but the system (at least in the US) just isn't set up for that.
Train travel is expensive and sparse and slow, biking most places is uncomfortable and unsafe due to crappy infrastructure.
I agree. Trains are often a more efficient, more comfortable, and greener way to travel. I would love to be able to take them more often on weekends here in the UK, but they are expensive to the point of costing more than air travel, which makes no sense.
Planes are cheaper as a function of the infrastructure needed to allow their use (? Feel free to correct me). As long as we allow airplanes companies to not pay for the long term externalities that they are creating planes will stay cheaper.
Train travel is expensive and sparse and slow, biking most places is uncomfortable and unsafe due to crappy infrastructure.