Horizontal Drawbridge Signals

[roadman65]

https://goo.gl/maps/BxoEUMsiDT77YfKJ7
Sea Bright, NJ.

https://goo.gl/maps/GTbrdFJqg6Fni6QP8
Holmes Beach, FL.

Both drawbridge signals. Both using horizontal signal mounts.

Although Florida uses horizontal mounts on many signals throughout the Sunshine State, they have many the standard vertical mounts. However almost all movable bridges they exclusively use horizontal heads.

New Jersey always had a mix use throughout the Garden State of either vertical or horizontal heads until the 80s and 90s where most NJ communities switched to vertically mounted heads including Newark, that always like the horizontal mounts.

Is it a rule someplace that drawbridge signals have to be horizontal mounted heads?  Also why did FDOT give up on the previous red flashing two section signals in the 1980s that was the norm for moveable bridges back before?

[Big John]

MUTCD now only allows the 3-section RYG or 2 red signals separated with a stop here on red sign.

No rule on orientation on the 3-section head though.  Florida may use horizontal fot increased wind loading at the crossings.