empty mileage
empty miles

The availability of land at these locations rendered the schemes much more economical, at the expense of additional empty mileage.

The provision of more ranks is also another measure being looked at as a means of cutting down on empty mileage and encouraging drivers not to continue driving around when empty.

In view of its request resulting in less empty mileage of hopper cars and better utilization of ocean containers, Prairie Malt believes that it is making a most reasonable request of the respondent.