NYC signal aspects.

g=green  y=yellow  r=red  s=numbered sign  >g<=flashing
vertical lines indicate the possible aspects of each signal head on a mast.

Name: Clear
Indication - Proceed.

g    g    g    g    g    g    g    g
r    g    r    g         r    g    s
r    r                   s    s    

Name: Appraoch Medium
Indication: Proceed approacing second signal at medium speed.

g    g    g
y    y    y
r         s

Name: Approach Limited
Indication - Proceed approacing next signal at limited speed. Train 
exceeding 60 m.p.h must at once reduce to that speed. Reduction to 60 
m.p.h. must commence before passing signal and be completed before 
accepting a more faavorable indication

 y    y    y
>g<  >g<  >g<
 r         s

Name: Limited Clear
Indication - Proceed: limited speed with interlocking limits.

 r    r
>g<  >g<
 r

Name: Approach
Indication - Proceed at limited speed preparing to stop at next signal.

 r    r
>y<  >y<
 r

Name: Approach Medium
Indication - Proceed approaching next signal at medium speed. Train 
exceeding limited speed must at once reduce to that speed. Reduction to 
limited speed must commence before passing signal and be completed before 
acceptiong a more favorable indication.

y    y    y
y    g    g
r         s

Name: Advance Approach
Indication - Proceed preparing to stop at second signal. Train 
exceeding limited speed must at once reduce to that speed. Reduction 
to limited speed must commece before passing signal and be completed 
before accepting a more favorable indication.

y    y    y
y    y    y
r         s

Name: Medium Clear
Indication - Proceed: Medium speed withing interlocking limits.

r
g
r

Name: Mediom - Advance Approach
Indication - Proceed preparing to stop at second signal: medium 
speed within interlocking limits.

r
y
y

Name: Medium - Approach Slow
Indication - Proceed at medium speed approaching next signal at slow 
speed.

r
y
g

Name: Approach Slow
Indication - Proceed approacing next signal at slow speed. Train exceeding 
medium speed must at once reduce to that speed.

y    y
r    r
g    g
     s

Name: Approach
Indication = Proceed preparing to stop at next signal. Train exceeding 
medium speed must at once reduce to that speed. Reduction to medium speed 
must commence before passing signal and be completed before accepting a more favorable indication.

y    y    y
     r    s
     s

Name: Approach - Restricting
Indication - Proceed, prepared to stop at next signal. Rains exceeding 
medium speed must at once reduce to that speed.

(semaphore at 45 degrees)

Name: Medium Approach
Indication - Proceed at medium speed preparing to stop at next signal.

r
y
r

Name: Slow -Clear
Indication - Proceed: slow speed within interlocking limits.

r    r
r    g
g

Name: Slow - Approach
Indcation - Proceed preparing to stop at next signal: Slow speed within interlocking limits.

(dwarf signal y over r)

Name: Restricting
Indication - Proceed at restricting speed.

r    r    r
r    y    y
y         s

Name: Stop
Indication - Stop.

r    r    r    r    r
r    s    r    r
s         r