But you aren't looking at the efficiency of these things. A hover car (we saw them in AGT) may be more efficient than a transporter for trips of up to 50 miles, say. An air tram (like we saw Kirk arriving in at the beginning of TMP) may be more efficient for trips of 1000 miles. You've got no justification for saying that a transporter is more energy efficient for all distances that are too far to walk when compared with all other forms of transport. After all, if that were the case, they'd just put a bunch of transporter relays throughout space and then beam from planet to planet a la Stargate.