Two-Way Left Turn Lanes
Many two-way streets have a center lane marked as a two-way
left turn lane (TWLTL). This lane is bordered on either side
by two yellow lines - the inner line is broken or dashed, the
outer line is solid. Pavement marking arrows may or may not
be present. This lane is for the exclusive use of left turning
vehicles and may be used by drivers making a left turn in either
direction. It shall not be used for passing or travel by a driver
except to make a left turn.
A TWLTL is provided to remove left-turning vehicles from the
through lanes and store those vehicles in the median area until
an acceptable gap in opposing traffic is available.
When TWLTL is added to a two lane or four lane street, accidents
may be reduced. This reduction is possible as stopped or slow
left-turning vehicles are removed from the through lanes. Drivers
in the TWLTL may feel more comfortable waiting for an adequate
gap in traffic, as they are protected from through vehicles.
Delay to through vehicles will also be reduced
because left-turning vehicles will not block the through lanes.
TO TURN LEFT FROM THE STREET:
Look for opposing vehicles already in the TWLTL, signal a
left turn, then drive completely inside the TWLTL lane. Don't
stop at an angle with the rear of your vehicle blocking through
traffic. Turn only when it is safe. Look for vehicles approaching
you in the same lane to make their left turns.
TO TURN LEFT INTO THE STREET:
Wait for an opening in traffic on the near side of the street.
Look for vehicles entering the center lane to turn left. When
safe, turn left driving completely into the center lane. Again,
do not stop with part of your vehicle blocking through traffic.
When safe, move to the right into the regular traffic lane
and proceed on your way.
on this link for the PDF file.