Sec.  90.242   Travelers' information stations.

   (a)  The  frequencies 530 through 1700 kHz in 10 kHz increments may be
   assigned  to  the  Public  Safety Pool for the operation of Travelers'
   Information Stations subject to the following conditions and limitations.

   (1) [Reserved]

   (2) Each application for a station or system shall be accompanied by:

   (i) A statement certifying that the transmitting site of the Travelers'
   Information Station will be located at least 15 km (9.3 miles) measured
   orthogonally outside the measured 0.5 mV/m daytime contour (0.1 mV/m for
   Class A stations) of any AM broadcast station operating on a first adjacent
   channel  or at least 130 km (80.6 miles) outside the measured 0.5 mV/m
   daytime contour (0.1 mV/m for Class A stations) of any AM broadcast station
   operating on the same channel, or, if nighttime operation is proposed,
   outside the theoretical 0.5 mV/m-50% nighttime skywave contour of a U.S.
   Class  A  station.  If the measured contour is not available, then the
   calculated  0.5 mV/m field strength contour shall be acceptable. These
   contours are available at the concerned AM broadcast station and FCC offices
   in Washington, DC.

   (ii) In consideration of possible cross-modulation and inter-modulation
   interference effects which may result from the operation of a Travelers'
   Information Station in the vicinity of an AM broadcast station on the second
   or  third  adjacent  channel,  the applicant shall certify that it has
   considered these possible effects and, to the best of its knowledge, does
   not foresee interference occurring to broadcast stations operating on second
   or third adjacent channels.

   (iii) A map showing the geographical location of each transmitter site and
   an estimate of the signal strength at the contour of the desired coverage
   area. For a cable system, the contour to be shown is the estimated field
   strength  at  60  meters (197 feet) from any point on the cable. For a
   conventional radiating antenna, the estimated field strength contour at 1.5
   km (0.93 mile) shall be shown. A contour map comprised of actual on-the-air
   measurements shall be submitted to the Commission within 60 days after
   station authorization or completion of station construction, whichever
   occurs later. A sufficient number of points shall be chosen at the specified
   distances (extrapolated measurements are acceptable) to adequately show
   compliance with the field strength limits.

   (iv) For each transmitter site, the transmitter's output power, the type of
   antenna utilized, its length (for a cable system), its height above ground,
   distance from transmitter to the antenna, and the elevation above sea level
   at the transmitting site.

   (3) Travelers' Information Stations will be authorized on a secondary basis
   to stations authorized on a primary basis in the band 510–1715 kHz.

   (4)  A  Travelers' Information Station authorization may be suspended,
   modified, or withdrawn by the Commission without prior notice or right to
   hearing  if  necessary to resolve interference conflicts, to implement
   agreements with foreign governments, or in other circumstances warranting
   such action.

   (5) The transmitting site of each Travelers' Information Station shall be
   restricted to the immediate vicinity of the following specified areas: Air,
   train, and bus transportation terminals, public parks and historical sites,
   bridges, tunnels, and any intersection of a Federal Interstate Highway with
   any other Interstate, Federal, State, or local highway.

   (6) A Travelers' Information Station shall normally be authorized to use a
   single transmitter. However, a system of stations, with each station in the
   system employing a separate transmitter, may be authorized for a specific
   area provided sufficient need is demonstrated by the applicant.

   (7) Travelers' Information Stations shall transmit only noncommercial voice
   information pertaining to traffic and road conditions, traffic hazard and
   travel advisories, directions, availability of lodging, rest stops and
   service stations, and descriptions of local points of interest. It is not
   permissible to identify the commercial name of any business whose service
   may  be  available within or outside the coverage area of a Travelers'
   Information  Station.  However, to facilitate announcements concerning
   departures/arrivals and parking areas at air, train, and bus terminals, the
   trade name identification of carriers is permitted.

   (b) Technical standards. (1) The use of 6K00A3E emission will be authorized,
   however N0N emission may be used for purposes of receiver quieting, but only
   for a system of stations employing “leaky” cable antennas.

   (2) A frequency tolerance of 100 Hz shall be maintained.

   (3) For a station employing a cable antenna, the following restrictions
   apply:

   (i) The length of the cable antenna shall not exceed 3.0 km (1.9 miles).

   (ii) Transmitter RF output power shall not exceed 50 watts and shall be
   adjustable downward to enable the user to comply with the specified field
   strength limit.

   (iii) The field strength of the emission on the operating frequency shall
   not exceed 2 mV/m when measured with a standard field strength meter at a
   distance of 60 meters (197 feet) from any part of the station.

   (4)  For  a station employing a conventional radiating antenna(s) (ex.
   vertical monopole, directional array) the following restrictions apply:

   (i) The antenna height above ground level shall not exceed 15.0 meters (49.2
   feet).

   (ii) Only vertical polarization of antennas shall be permitted.

   (iii) Transmitter RF output power shall not exceed 10 watts to enable the
   user to comply with the specified field strength limit.

   (iv) The field strength of the emission on the operating frequency shall not
   exceed  2 mV/m when measured with a standard field strength meter at a
   distance of 1.50 km (0.93 miles) from the transmitting antenna system.

   (5)  For  co-channel  stations operating under different licenses, the
   following minimum separation distances shall apply:

   (i) 0.50 km (0.31 miles) for the case when both stations are using cable
   antennas.

   (ii)  7.50  km  (4.66  miles) for the case when one station is using a
   conventional antenna and the other is using a cable antenna.

   (iii)  15.0  km  (9.3 miles) for the case when both stations are using
   conventional antennas.

   (6)  For  a system of co-channel transmitters operating under a single
   authorization utilizing either cable or conventional antennas, or both, no
   minimum separation distance is required.

   (7) An applicant desiring to locate a station that does not comply with the
   separation requirements of this section shall coordinate with the affected
   station.

   (8) Each transmitter in a Travelers Information Station shall be equipped
   with an audio low-pass filter. Such filter shall be installed between the
   modulation limiter and the modulated stage. At audio frequencies between 3
   kHz  and 20 kHz this filter shall have an attenuation greater than the
   attenuation at 1 kHz by at least:

   60 log[10](f/3) decibels.

   where “f” is the audio frequency in kHz. At audio frequencies above 20 kHz,
   the attenuation shall be at least 50 decibels greater than the attenuation
   at 1 kHz.

   [ 43 FR 54791 , Nov. 22, 1978;  44 FR 67118 , Nov. 23, 1979;  49 FR 48712 , Dec.
   14, 1984, as amended at  54 FR 39740 , Sept. 28, 1989;  56 FR 64874 , Dec. 12,
   1991;  62 FR 18928 , Apr. 17, 1997;  65 FR 60877 , Oct. 13, 2000;  67 FR 63289 ,
   Oct. 11, 2002;  72 FR 35195 , June 27, 2007]