Originally Posted by RichardKenner

Perhaps a better way to say it is that these cases say that the right to travel is "merely" a right to "travel", that the point of the right is that a person be able to travel. It doesn't require that the government allow the person to travel in any specific way. I believe, for example, that it would be within the powers of the government to say that certain Interstate highways could carry commercial traffic only as long as there were other Interstate highways that passengers could use to get from state to state.

In other words, saying "you have the right to travel from NY to Florida" doesn't mean "you have the right to drive to Florida on I-95" or "you have the right to take a train from NY to Florida": it simply means "you have the right that there be some way to get from NY to Florida".

I agree with TSORon's comments that various modes of travel can have rules and regulations, but don't see the necessary relevance of that to whether there's a right to travel by a particular mode. The courts are often asked to decide whether a particular rule or regulation infringes on a "right". The fact that there's some rule limiting X doesn't mean that there's no right to do X, but the absence of a rule doesn't mean there is such a right.