The Sky Chart shows the directions, time of day, and planets and houses in the chart
wheel.  (The sacred numbers of the Zodiac are 3, 4, & 12 and their divisions)

Why are the directions opposite a road map?

Because when we watch the Sun, Moon, and planet's movement we have to face
(the ecliptic) to see them.

To learn more about the birth chart & Astrology:
Sun Signs