Imagine a bus system where the buses have "circular" routes, meaning in topological terms that they have closed loops but don't just retrace their stops along the same roads.

The +6 goes around the loop in a clockwise direction (to the right, if the second hand at the 12, you facing it == looking down on the bus route from further out, ala Google Earth).

The -6 goes around the loop in a counter-clockwise direction, which, from the center of the Earth, will appear clockwise.

Student exercise:  face your partner and make your hand go in a counter-clockwise circle *for your partner* not for you.  

Student exercise:  Watch yourself on TV or computer, camera facing you.  Now look in the mirror.  What's the difference?  To make it your hand move clockwise in the mirror, what do you have to do?

Visiting speaker:  bus routing software development specialist from Metro (a regional government we have out here in the "Far West").

The way we do it now, it's all one bus route with the idea that it turns around and comes back along the same path, though because of one-way streets there will be deviations.  

The bus has a "where to" sticker marking the "end of the line" where it turns around an heads back.

This is more like the track system with tracks built in pairs.  In a funicular, there's only one track but it divides in the middle to let the cars pass.

In this other way of doing it (loopy buses), people think of bus routes as wandering around in partially overlapping routes that close into loops, with a + direction and a - direction, also called R and L.

Talking about handedness more, chirality, is a hallmark of STEM-informed curricula.  Dan Suttin does a good job with this in his webinar, talking about chirality and enantiomorphs (same thing).

One might speak of taking the bus number 6 in the minus direction (rather than "negative") but that's urban slang.  "Negative" is more "couth" (the negative of uncouth).

More likely you'd just say "take the positive 12 to the Great Fountain, transfer to the negative 33, ride three stops, take the positive 9 two stops to Myrtlewood Street and voila, you're there."

The linking of "positive" and "right" is neurolinguistic and I haven't tried to break it in choosing to look at bus routes from above rather than from below.

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We think of time as moving "forward" i.e. "in the positive direction" whereas "going backwards in time" is into the past.  We tend to associate "positive" more with "up" and "right" than with "down" and "left".  This is in part cultural as some languages advance through time to the left i.e. you read them right to left (Hebrew, Arabic... Farsi).

Related concepts:  Do / Undo.  Reversibility.  Arrow of time.  Irreversibility.  Function / Inverse Function.

Lets remember that in some ecosystems the positive direction is inward towards a convergence, a centralizer (the protons at the nucleus), while the negative is shaped around it as electronic fields, attracted but not convergent, not symmetric. 

This is different from N / S.  There's "focal positive" (coming in from all directions) and "focal negative" (radiating away in all directions).  Left and right are more lateral motions.  That which has a focal point or center also turns.  The equator is more like a number line, going West and East from 0, the Prime Meridian.

"Did they teach anything about latitude / longitude when doing coordinate systems with ya?  No?  What school did you say that was?"

Kirby