encyclopedia

BLANKET PURCHASE ORDER

A pre-contractual agreement with a vendor that establishes an agreement for the purchase of supplies or services which allows the MTA to make small purchases without the issuance of a purchase order for each individual purchase. Payments are made on…

BLD LINK (BUILD LINK)

A series of programs that create walk acces links for the transit network building process.

BLOCK

Length of track of defined limits, the use of which is controlled by signals, Cab Signals or Central Control Facility (CCF) authorization.

BLOCK GRANTS

Aid directed at broadly or functionally defined purposes. In comparison with directed grants, more reliance is placed on state initiative, local initiative, or both in this form of grant. (TRB)

BLOCK INDICATOR

A device, generally located near a turnout switch, that is used to indicate the presence of a train in the block or blocks leading to that switch. (TRB)

BLOCK MILEAGE (BLOCK KILOMETERS)

The distance traveled daily during the operating schedule of a transit unit (vehicle or train) from pull-out to pull-in, including schedule and deadhead service. (TRB)

BLOCK SIGNAL

A fixed signal installed at the entrance of a block to govern trains entering and using that section of track. (TRB)

BLUE FLAG/LIGHT

Blue flag/light displayed on both ends of a train is an indication that rail employees are on or about the vehicle.