3M
From HighwayWiki
Some really random text about 3M's traffic division here. (Also, be sure to reference that they made a bi-modal, time-programmable sign, too!)
Products:
Signals
M-123 Programmable Visibility Prototype Signal
M-131 Programmable Visibility Signal Wiki Page
M-131R Dual Indication Signal Signal
M-132 Bimodal Ball/Arrow Signal
M-133 Dual-Indication Signal