encyclopedia

COMMAND AND CONTROL SYSTEM (C&C)

In rail systems, any means of adjusting and maintaining prescribed headways; effecting starting and stopping, merging, and switching; and controlling other such functions. It is usually considered to include transit unit (car or train) protection, transit unit operation, and line…

COMMAND ZERO

Look ahead feature of the train control system that prevents a train from leaving a station when traction power is de-energized ahead.

COMMERCIAL PAPER

Short-term interest-bearing promissory note secured by pledged revenues and a liquidity/credit facility. The maturity can range from 1 to 270 days.

COMMISSION HOURS

Daily periods when customer transit use is the highest, typically 7 a.m. to 9:30 a.m. and 4 p.m. to 6:30 p.m. Also see Rush hour, Peak period.

COMMITTED PROJECTS

Committed projects include any project for which funding has been approved by the Metro Board.

COMMON CARRIER

A carrier that holds itself out as serving the public (or a segment thereof) indifferently (i.e., without regard to the identity of the customer and without undue discrimination).

COMMON GATEWAY INTERFACE

An interface for programmers who build script or applications which run behind-the-scenes on a web server. These scripts can generate text or other types of data on the fly, perhaps in response to input from user or from mining information…

COMMUNICATION LINK

A system of hardware and software connecting two end users.

COMMUNICATION SYSTEM

A system containing an information source, an information link or user, and a communications link for moving the information, intelligence or control between the source and link.