Yes, as others have said, there are a few out there in use. They are not used everywhere; only in key locations (where there is a high accident rate, unusual intersection, history of driver violations, etc.)
The most interesting (and first one) I've seen was in Laramie, WY - getinofficer will know where I'm talking about. This is also a mid-block traffic signal (no street intersection). It was placed to allow us poor, starving college students a safe crosswalk to walk, er stagger, no crawl back to the dorms from the "Mini Dome Mall" (a interesting collection of three bars and a liquor store)
Believe me, I was glad to have it. One semester the Drawbridge had "kamikaze night" (pitchers of them for $2.50) every Wed

Made Chem Lab interesting the next morning

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2001 Coupe, DBGM, Oak, MN6, F45, & all the goodies
Mods: Gold Rims; gold lettering kit; painted fuel rail covers; cold air screens; 02 ZO6 air lid; hood seal; Hurst shifter; A&A Corvette Stage II heads and cam; mucho Zaino!
Married in the new Vette 10/9/00