Excerpt from a page of the 2018 Kentucky DMV Handbook (Driver’s Manual)
RULES OF THE ROAD (page 8)
Without traffic laws, rules, and controls, travel by a motor vehicle would be unsafe and impractical. Drivers are tested and licensed to operate motor vehicles in an effort to make travel safe for everyone. This section provides you with information on:
Control of Traffic at Intersections, Traffic Signals, Traffic Signs, Right-Of-Way, Parking, Use of Lanes, Through Driving, Passing, Laws for Turning.
CONTROL OF TRAFFIC AT INTERSECTIONS
An intersection is any place where two roads meet. At an intersection, there may be traffic signals, signs, or right-of-way rules to control traffic.
The three main colors that guide traffic are:
RED means STOP. YELLOW means WARNING. GREEN means GO, if safe.
RED: A red light means “stop” behind a crosswalk or stop line until the green light appears. You may turn right after stopping, if there is no approaching traffic, unless a sign is posted prohibiting such right turns. Even though the light is red, a turn is permitted from a one-way street into the nearest lane of another one-way street, running in the direction of that turn.
YELLOW: A yellow light means the traffic signal is about to turn red. Stop if you can do so safely. A vehicle may clear an intersection on a red light, if the vehicle entered the intersection while the signal was yellow; but it is against the law to enter an intersection after the light turns red.
GREEN: If the way is clear, after yielding the right-of-way to other vehicles and pedestrians lawfully, within the intersection, you may go straight, or turn left or right, unless such turns are prohibited. Left turns on green must yield to through traffic coming from the opposite direction.
A flashing yellow light means that you must slow down and watch for others. It is found at intersections, construction areas, and on some vehicles, like tow trucks.
A flashing red light means that you must come to a full stop and proceed only when the way is clear.
When two flashing red lights mark a railroad crossing: stop and proceed only after the lights stop flashing, and you determine that no train is approaching. The familiar cross-buck sign near the tracks is a regulatory sign that means the same as a yield sign.
Some intersection traffic lights have lighted arrows, in addition to the regular lights. A green arrow means you may go in the direction of the arrow, if you are in the proper lane.
A flashing yellow arrow means that you may proceed with caution in the direction of the arrow.
A green arrow pointed upward means that you may go “straight ahead.”
A red arrow means that there is no turning in the direction of the arrow, until it turns green.
When there is more than one traffic light, obey the one that is over your lane.