Each mode of transportation has its merits, however, I vote for trains, 100 percent.
Cars are very convenient, personalized, and comfortable, but on a long trip, someone has to drive and pay attention to the road. If the driver lacks skill, the passenger(s) may need to pay attention as well : ) Either way, someone has to always be paying attention and watching the road, which detracts from the mutual enjoyment of the roadside scenery. In a car, you also have to stop at a roadside rest stop for bio breaks, and depending on whether or not it's a toll road, selection of eating establishments may be limited. Some states still have full service stations, so if a person is not accustomed to pumping their own gas, there is also the trauma of self serve stations!! Cars conveniently go where you drive them, so you have the flexibility of pulling off and digressing from your route whenever you wish, that is their primary advantage.
Planes are fast, once you're in the air. The problem is, getting in to the air! I have never encountered so many scheduling delays as when I'm at an airport. Plane routine: check in and go on a long trek to the gate, go through security, if there's a connecting flight, go on a long trek to the connecting gate, land and go on a long trek to the baggage claim area. While on the plane you have a little seat and are usually squished between two other people who also have little seats. The bathrooms aren't bad, but people have to constantly get up and down to accommodate the bio needs of other passengers. I haven't had a meal on an airplane in quite some time since budgets are constantly being cut, but when I did, they were merely passable, nothing to shout about. In the airport food is expensive, there are times when it's impossible to find a place to sit, and if you're stuck for hours due to delays, there is nowhere to go. Planes are fast, that is their primary advantage.
Trains.....aaaahhhhh trains! Local travel on trains is fun, fast, and convenient. Long distance travel on trains is even more fun, just as fast as a car or faster, depending on stops, and allows for mutual enjoyment of the trip. Our train ride from Washington, DC to Chicago on the Capitol Express started our vacation the second we stepped onto the train. Since we booked overnight train accommodations, we had use of the Station Lounge and all the comforts therein (refreshments, plenty of seating, luggage stowage, and wireless computer service). It's a short walk from the station to the train car entrance, with porters waiting to help with luggage. Once in our cabin, there was a long sofa type seat on one side and a chair facing the sofa seat, with a fold up table in between. There was coat storage and a booth that housed the toilet and shower. We stored our larger suitcase on the lower deck, and took the smaller suitcase to our room upstairs; the suitcase stowed well under the single seat. We plugged in our cell phones to recharge them, removed our shoes, sat back in our chairs, and enjoyed regular conversation without worrying about infringing on the space or boundaries of others. The porter came to take our dinner reservation (all meals included in the overnight fare), and the food at mealtimes was diverse as well as delicious. We ate meals in the dining car at tables covered with table cloths and on dishes that were real. We enjoyed time in the lounge car when we felt like taking a little walk. We arrived at our destination earlier than scheduled and we already had our luggage in our hands to walk to the car rental booth just inside the station. Layover to await a connecting train? Simply walk out of any train station and there is something to do because you're in the middle of the city. There are so many advantages to taking the train, their primary disadvantage is they are not as fast as planes, and extra travel time needs to be accounted for when taking long trips. More detailed accounts of this trip to follow.