Rule	Aspect	Name	Indication
501		Clear	Proceed
501A		Approach Medium	Proceed approaching next signal not exceeding 30 mph
501B		Diverging Clear	Proceed on diverging route at prescribed speed
501C		Diverging Approach Medium	Proceed on diverging route at prescribed speed and approach next signal not exceeding 30 mph
501D		Restricting Approach Medium	Proceed at prescribed speed approaching next signal not exceeding 30 mph
501E		Approach	Proceed prepared to stop before any part of train or engine passes next signal
501F		Diverging Approach	Proceed on diverging route at prescribed speed prepared to stop before any part of train or engine passes next signal
501G		Restricting	Proceed at Reduced Speed to make any Reduced Speed movement. Trains moving on or entering upon a track signaled for that direction must proceed as prescribed by rule 501-E
501H		Take siding indicator for hand operation of switch	Hand operate switch and enter siding
501I		Permissive	Proceed at Restricted Speed through entire block
501J		Stop	Stop before any part of train or engine passes the signal

Notes:
CB&Q did not use Stop & Proceed.
Some semaphore aspects differed from color light aspects.

Created 12-27-2002
Updated 01-15-2006