CFR / 
Title 49
 / 
Part 236
 / 
Sec. 236.813 Speed, slow.
A speed not exceeding 20 miles per hour.
Sec. 236.813a State, most restrictive.
The mode of an electric or electronic device that is equivalent to a track relay in its deenergized position.
[49 FR 3388, Jan. 26, 1984]