Consistwency of rules.

I have 2 questions about application of railroad regulations.

1. Why are subways not subject to all of the same FRA rules as other railroads?

2. Why is it that locomotive driven trains have to ring a bell while going through stations, but not MU trains? I've also noticed that trains operating push/pull have to ring a bell when passing through a station locomotive end first, but not always when the remote cab is leading. Why is this the case when the safety issues are the same?

Subways are not part of general system of railroads in US , they are normally within a state or city and subject to other than federal rules.

a bell is not a FRA required Item, but a safety appliance required by rules. some commuter agencies have a misconception that a cab car does not require a bell. but FRA rules state a Cab car is a locomotive ?? so what is it...

§ 229.14 Non-MU control cab locomotives.

On each non-MU control cab locomotive, only those components added to the passenger car that enable it to serve as a lead locomotive, control the locomotive actually providing tractive power, and otherwise control the movement of the train, are subject to this part.

Thanks, Dutch. More convolution in our seas of rules.