GMC 2009 Acadia - Manual (Page 456)

When you are approximately 1/4 mi (400 m) from the
next maneuver in city driving, the screen displays
the name and a detailed view of the next maneuver. On
the freeway, these details appear at 1 mi (1200 m)
from the maneuver.
3–D Lane Guidance
Some major metropolitan areas may include a 3–D lane
guidance feature for highway exits and junctions. This
feature gives a more detailed representation of the exits
and junctions on the route. Cities that include this feature
are New York, Los Angeles, Chicago, Detroit, and San
Francisco, and may also include Philadelphia,
Washington D.C., and other major highway junctions.
2-12