This is the current standard for a basic 12-12-12 assembly. For all style 5 signals, signal heads are usually mounted so the top of the backplate is roughly flush with the top of the arm, although there are a few exceptions. Horizontal signals use a single-point mount: from the arm the connection comes forward to the horizontal centre of the signal, then splits right and left to come down and connect on either side of the signal head (it's hard to describe in words). In most cases, there is an 8-8-8 auxiliary signal as shown here in the far left corner of the intersection, often on the pole of the main assembly facing traffic on the cross street. This auxiliary signal will be there unless there is a left turn signal of some sort (protected-permissive or protected-prohibited; anything with an arrow), a left turn is not possible/permitted, or there is no traffic coming from the opposite direction. For a one way street, the arm can connect to both poles, and there will be an auxiliary signal on both sides. The positioning of the overhead signals are determined by the number of lanes they are controlling, as detailed in the Traffic Control Policy Manual.

Back