encyclopedia

MICROMETER

A unit of measure equal to one millionth of a meter (one thousandth of a millimeter). Airborne particulate matter is measured in micrometers to help determine its level of threat to human respiratory health.

MICROWAVE LOOP

Backbone of MTA’s telecommunication network. Seven microwave repeater sites are configured in a loop with the Union Station Gateway Building as the terminal and hub. The network of microwave communications equipment is installed at the Gateway Building, most MTA divisions,…

MICROWAVE TRANSMISSION

A high capacity transmission medium for radiated signals that uses the radio frequency system; when acting in the receiver capacity, a modem decodes incoming frequencies.

MIDBLOCK STOP

A transit stop located at a point away from intersections. (TRB)

MILE POST

A sign along the railroad (or highway) indicating the number of miles from a reference point. On the Southern Pacific, miles are from San Francisco, on Metrolink, they are from Los Angeles. Abbreviated MP or M.P.

MINI SYSTEM

A form of collector-feeder-distribution system generally utilizing small scale people-mover vehicles, moving sidewalks or other similar means for distributing or collecting passengers in the vicinity of a rapid transit station.

MINIBUS

Small bus usually operated on short trip or circulation routes in a downtown area, airport or other dense population area. The name originates from the trade name “Minibus” whose buses were manufactured in Pico Rivera. In the seventies, the RTD…

MINIMUM OPERATING SEGMENT

Original names for the three Metro Red line project modules. Now called Segments.