Linear adjective
arranged in or extending along a straight or nearly straight line: linear arrangements | linear in shape | linear movement.
consisting of or predominantly formed using lines or outlines: simple linear designs.
involving one dimension only: linear elasticity.
Mathematics able to be represented by a straight line on a graph; involving or exhibiting directly proportional change in two related
quantities: linear functions | linear relationship.
If I refer to twenty linear miles, do those twenty miles need to be all in one straight line? Or does twenty linear miles simply mean twenty miles of length, whatever the route, as opposed to twenty square miles?
If linear describes the miles, collectively, it should all be in one straight line, but linear could also refer to each individual mile, like a linear foot.
The phrase may be ambiguous, but what's the primary interpretation?
Edit after first close vote:
If a twenty-mile long line is not straight, can you call it twenty linear miles?
Best Answer
It is, in fact, ambiguous. The term linear [unit] is most often used to distinguish from square [unit], and most often refers to things that are already straight. For example:
However, as is implied by the usage above, a total linear measurement amount can aggregate several individual measurements; for example, if you were building three shelves that were each four feet long, you would need twelve linear feet of shelving.
Linear miles is subject to similar ambiguity. It can mean X miles-in-a-straight-line:
Here, we are told that the Route is 68.73 miles long, so the only possible interpretation of it crossing "8 linear miles" is that this is a measurement, in a straight line, across the total terrain covered.
However, it can also mean X miles-if-you-stretched-all-the-measurements-into-a-straight-line. For example:
Here, unless the City of Green is absolutely enormous, and all on one long, straight street, the 500 linear miles must be an amalgamation of the many twists and turns of sewer pipes and ditches that make up the city's storm water drainage system.
Unfortunately, this means that there isn't an easy way to know what is meant by linear miles; it just has to be determined from context, and careful writers should include an explanation of how they are using the term.