Interchange

[Datafever]

[I thought I posted this, but now I don't see it, so pardon if this is a duplicate.]

Could someone explain to me how interchange between railroads works?

For example, if a shipper that is directly connected to railroad A ships a product to a receiver that is directly connected to railroad B, how does that work?  Who sets the price that the shipper pays?  How do railroad A and railroad B determine how much each receives?

To complicate matters a little, how does the situation change if the only route connecting railroad A and railroad B is railroad C?

[JSGreen]

Another question about interchange....

it occured to me in reading the threads on open access et al...can Railroads be REQUIRED to interchange?  In the thread about the MDR (Montana Dentist Railroad), if he is successfull in beginning a branch line which used to be a part of BNSF, is the BNSF obligated to service an interchange? Can they choose to interchange at only one end, but not both, assuming that it  connects on both ends....Is there a mechanism to prevent setting the rates so high it drives the MDR out of business

inquiring (and otherwise idle) minds want to know...