Speed is relational with mind. You can't imagine infinite speed. And you can't imagine speed which is not slow in its slow. Both sentences above sum up true sense about speed. Speed is some in all. You are not supposed to say that walking is speed. So you rely on speed which is not infinite and which is slow in its slow. Rails makes this as possible and safe. Road unlike rail is prone to accident and less-passenger load. My point is that railway movement "philosophy" need be included to academic curriculum of primary schools and intermediate(plus two) colleges.