There are a number of regulations regarding the current usage of Stop/Slow paddles. The MUTCD specifies that the paddles should be at least 18” wide and have 6” tall letters (and this was an update of the original 1971 ANSI standard that recommended 24” wide paddles). Please also check, though, with the various state and local requirements for proper paddle size and reflectivity. The MUTCD standard mentions that to “stop road users, the flagger shall face road users and aim the STOP paddle face toward road users in a stationary position with the arm extended horizontally away from the body. The
free arm shall be held with the palm of the hand above shoulder level [emphasis added] toward approaching traffic.”
Then, the standard goes on to state, “[to} direct stopped road users to proceed, the flagger shall face road users with the SLOW paddle face aimed toward road users in a stationary position with the arm extended horizontally away from the body." The flagger shall motion with the free hand for road users to proceed. To alert or slow traffic, the flagger shall face road users with the SLOW paddle face aimed toward road users in a stationary position with the arm extended horizontally away from the body.”
The handheld signs should be octagonal with a red background with white letters and a white border. The Slow sign, on the backside of the Stop sign, is the same shape but with an orange background with black text and a black border.
MUTCD and OSHA specify an octagonal shape. Letters should be at least 6” tall. Reflectorized paddles should be used at night.