The earliest lanterns probably would have been the hot blast lanterns such as the Dietz Hy-Lo. With a red globe they would warn the motorist of danger. Their light/signal output, however, was soon surpassed by cold blast lanterns.
The tall and standard short-globe lanterns probably never did well in this application - they consumed too much fuel and were better for lighting. However the Little Wizard (Embury #10) globe (Adobe Acrobat®) lanterns were well-accepted for this challenge, particularly the large font versions.
The same lantern, probably the last remaining traffic lantern, is still available today in the form of the Dietz Little Wizard No1 (and more recently the V&O #30LT/RCM No 1):
Dietz even offered the Little Giant and Contractor with a special #221 burner for a 3/8" wick in order to offer existing Little Wizard customers an extended (100 hr.) burning time as an alternative to dead flame lanterns. These special order lanterns were popular in Southern California.
HAPPY 50th BIRTHDAY !
For the 1958 model year Dietz merged a redesigned streamlined D-Lite with the former Embury name to produce the Air Pilot.
This lantern was offered in yellow as well as the standard blue and gained some popularity as a highway warning lantern.