This
section is a summary of the AAA Foundation for Traffic
Safety film,
"Signs, Signals and
Roadway Markings."
Along the roadway, there are hundreds of images that help you find your way. Your job
as a driver is to pick out the information that will help you arrive safely at your
destination.
You get much of this information in the form of traffic control signs, signals, and
markings. Recognizing these signs, signals, and markings can give you advanced notice of
changes ahead -- such as merges, reductions in speed or upcoming intersections. Knowing
what they mean allows you to anticipate and react to changing traffic conditions so you
can drive more safely and smoothly.
This section will discuss the rules and underlying logic behind traffic signs, signals,
and markings and why they are important to you.
Markings
The streets themselves communicate with their painted messages called markings.
There are two general rules about markings that tell you where you may and may not
drive.
- The first rule is that white lines are on the right side of each traffic lane and yellow
lines are on the left.
- The second rule is that solid, or unbroken, lines tell you where you may not pass or
change lanes; dashed or broken lines permit you to pass or change lanes.
For example, on a two-lane road, the solid white line to the right marks the edge of
the roadway. The yellow line on the left separates you from oncoming traffic.
A double solid yellow line on your left means that it is not legal for you or for
oncoming traffic to pass. If there is a dashed and solid line together and the broken line
is on your side of the road, you may pass traffic ahead of you if you can do so safely.
However, opposing traffic is not allowed to pass the solid line.
A dashed yellow line on the left means that you and the opposing traffic may pass. If
you decide to pass, make sure you have enough room to pass safely.
On multi-lane roads with medians, broken white lines usually separate the lanes of
traffic going in the same direction. Solid yellow lines mark the left side of the road and
solid white lines mark the right side.
A single solid white line is intended to discourage, but not prohibit you from changing
lanes. Although in some states crossing a single solid white line is illegal, it is legal
to do so in California, unless the solid white line designates a turn.
Keep in mind that the single solid white line is there for a reason and is meant to
discourage you from crossing it. If you decide to cross it anyway, you may be guilty
of an unsafe lane change depending on the circumstances. Only cross a solid white
line if it is safe to do so.
Very short dashed white lines indicate a merge lane.
You may need to make a lane change to continue going
straight ahead.
Yellow warning signs also alert you to a merge lane.
Short white lines like these guide you through large complex intersections.
In addition to lane markings, you will also often see reflectors. Again, white marks
the right edge and yellow the left; these lane markings are especially helpful at night or
when it is hard to see the edges of the road.
