Horizontal vs Vertical Signals: Advantages of Each

[kphoger]

What are the advantages of vertical signals?
What are the advantages of horizontal signals?

mounting hardware?
clearances?
flexibility in design or layout?
et cetera?

[snowc]

Vertical signals: More easier to learn from. NC mostly has Vertical traffic lights.
Horizontal: More harder for me to learn, especially in TX.
Clearances are bad in vertical.

[kphoger]

to learn from

What do you mean?

[zachary_amaryllis]

Is there a standard that says which way the horizontal ones are mounted (like.. red to the left), just like the red is on top when it's vertical?

Common sense says to me 'yes'...

[cjw2001]

Is there a standard that says which way the horizontal ones are mounted (like.. red to the left), just like the red is on top when it's vertical?

Common sense says to me 'yes'...

Priority of order from https://mutcd.fhwa.dot.gov/htm/2003r1/part4/part4d.htm The relative positions of signal lenses within the signal face shall be as follows:

In a horizontally arranged signal face from left to right:
CIRCULAR RED
Left-turn RED ARROW
Right-turn RED ARROW
CIRCULAR YELLOW
Left-turn YELLOW ARROW
Left-turn GREEN ARROW
CIRCULAR GREEN
Straight-through GREEN ARROW
Right-turn YELLOW ARROW
Right-turn GREEN ARROW

[kphoger]

Is there a standard that says which way the horizontal ones are mounted (like.. red to the left), just like the red is on top when it's vertical?

Common sense says to me 'yes'...

Priority of order from https://mutcd.fhwa.dot.gov/htm/2003r1/part4/part4d.htm The relative positions of signal lenses within the signal face shall be as follows:

In a horizontally arranged signal face from left to right:
CIRCULAR RED
Left-turn RED ARROW
Right-turn RED ARROW
CIRCULAR YELLOW
Left-turn YELLOW ARROW
Left-turn GREEN ARROW
CIRCULAR GREEN
Straight-through GREEN ARROW
Right-turn YELLOW ARROW
Right-turn GREEN ARROW

I just made a visual representation.

[Hobart]

The main reason different jurisdictions use different standards are because they need different things.

Horizontal signals on mast arms reduce the surface area of the entire signal assembly, which is why they're favored in areas with hurricanes.
Vertical signals on mast arms reduce the area of the assembly in terms of "where can snow fall and stick to this signal."

Horizontal signals are also easier to see under underpasses, and take up less height. This is especially shown where a jurisdiction with normally vertical signals uses horizontal ones to either keep the height of the intersection down, or on approaches leaving a tunnel.

[Big John]

Vertical signals are also easier to see under underpasses, and take up less height. This is especially shown where a jurisdiction with normally vertical signals uses horizontal ones to either keep the height of the intersection down, or on approaches leaving a tunnel.

Do you mean horizontal?

[Hobart]

Vertical signals are also easier to see under underpasses, and take up less height. This is especially shown where a jurisdiction with normally vertical signals uses horizontal ones to either keep the height of the intersection down, or on approaches leaving a tunnel.

Do you mean horizontal?

This shows the merits of good proofreading (something I did not do). I will correct that.

[jakeroot]

Apart from some rare situations, vertical signals are definitely the preference for post-mounted signals as they are less likely to be hit. And probably for aesthetic reasons, too.

That said, they do exist for unusual situations.