current_directionStringIf you are traveling, say, Northbound on a North/South highway, this value will be "North"

Possible values: North, South, East, West, Outer, Inner
reverse_directionStringAnd this value would be "South"

Possible values: same as above.
direction_suffixStringAnd this value would be "bound" so that you could combine it with current_direction or reverse_direction.

Possible values: "bound" (for N/S/E/W) and " Loop" (for Inner/Outer)