Chevrolet 1993 Astro Passenger Owner's Manual page 157

AM402003
ORANGE indicates road construction or maintenance. You'll want to slow
down when you see an orange sign,
as part of the road may be closed off
or torn up. And there may be workers and maintenance vehicles around,
too.
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' A I L E
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A
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GREEN is used to guide the driver. Green signs may indicate upcoming
freeway exits or show the direction you should turn to reach a particular
place.
BLUE signs with white letters show motorists' services.
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