The driver broadcast information ( ARI ) was an auxiliary service of FM radio. The system served the identification and geographic allocation of traffic messages. It was developed by Blaupunkt together with the ARD broadcasting organizations (in charge was the Institute for Radio Technology ) and from 1974 to 2008.

  • 4.1 Function
  • 4.2 Control of RDS broadcasts with the Hinz- trill
  • 4.3 history


The ARI identifier transmitted from radio stations during normal program with the non-audible, additional frequency of 57 kHz and sent three identifiers:

  • The transmitter identification (SK) showed the presence of a traffic information station at
  • The area identifier (BK) submitted an identifier between A and F for the geographical area of ​​responsibility of the sender
  • The announcement identifier ( DK ) announced the announcement of traffic messages to

Station identification and area identification were broadcast continuously by stations available with the announcement identifier corresponding during the traffic reports. If no control line from the broadcaster was available to the preset station location, could the ARI announcement identification with the Hinz- trill ( the "Traffic beeper " ) are turned on.

With the help of the ARI signal radios were based on both the SK and BK channels that traffic messages radiated identify as also differ about the DK between traffic announcements and the current program. For the driver that was recognizable, for example, by lighting a yellow lamp for traffic channels. In more sophisticated car radio also has a display or selection of the traffic area corresponding to the area identifier BK was possible.

Receiving frequencies and area ID of the receivable FM traffic radio station were reported from 1974 to 2003 on blue information signs ( Highway Code 368 characters ) on the motorways. If multiple traffic stations were receivable, which happened after the introduction of private broadcasting, several signs were at a distance of several hundred meters off the highway. With activated ARI function matching traffic stations were easy to find.

Muted or located in the cassette holding car radios were automatically adjusted above on the basis of DK for the duration of traffic announcements and possibly interrupted the cassette operation, so that a miss of the messages was no longer possible. If the car radio supported adjustment of the area identifier and the matching field was set, was also ensured that relevant to the local area traffic reports have been received.

The introduction of ARI was motorists therefore possible to obtain by said traffic messages without listening to the radio constantly.


The ARI identifier transmitted from radio stations in addition to the normal program with a subcarrier frequency of 57 kHz ( = 3 × 19 kHz, stereo transmitters phase locked to the stereo pilot tone ) and provided the three identifiers:

  • The transmitter identification (SK) is the keynote of 57 kHz itself and indicates the presence of a traffic radio transmitter.
  • The area identifier (BK ), which transmits the transmission range of the transmitter ( A to F) is generated by verschiedenfrequente, non-harmonic amplitude modulation by 60 %.
  • The announcement identifier ( DK ), which points to important announcements such as traffic is generated by additional modulation amplitude by 30% at a frequency of 125 Hz

If no traffic information could be transferred (eg sometimes at night when the transmission mode from the tape ), the ARI station code was (and thus also the BK) off.

Area identifier

The area codes were distributed as follows among the individual federal states and cantons:

Status: February 2001

ARI in conjunction with PCI

In 1983 Blaupunkt Berlin IQR 83 with the first car radio with PCI before, a system in which a transfer station database via data cassette on the radio and was stored in this durable. By evaluating the area identifier and frequency while driving, these devices were automatically switch to a transmitting station with better reception values ​​able to display the station name instead of just the area identifier A to F and when leaving the coverage area. For this purpose, we used a second background receiver permanently was searching the FM band by other stations and their area IDs. Since the transmitter landscape constantly changed, and the display to prevent false name, a regular update with a new data cartridge was useful. The last PCI radio was the Berlin IQR 88, whose production was discontinued at the end of the eighties.

Introduction and shutdown

ARI has been developed from 1972 to automatically detect and to process traffic announcements on the acoustic characteristics by Hinz- trill out into the terminals, so the car radio. In various experiments in the mountainous landscape of Switzerland is the superposition of the normal program described proved with the subcarrier frequency of 57 kHz as the most stable solution. This resulted in the introduction of this procedure on 1 June 1974 at the FM radio in Germany, initially limited to selected ARD station. With the advent of private broadcasting in the 1980s, then multiplied the number of traffic information station. From 1980, in Switzerland commissioned using the PTT (now Swisscom ) for the first FM chains of the language regions.

Parallel operation of ARI conceived by the European Broadcasting Union, more modern Radio Data System (RDS) was officially introduced by the broadcasters on April 1, 1988. In it the ARI functions station identification and announcement identification be incorporated as TP or TA signal. Due to the ease of signaling, however, comes from ARI in contrast to RDS with lower signal levels and may even in noisy receipt nor a reliable indicator of station identification, range and announcement identification offer.

From the mid- 1990s car radio without RDS technology were then scarcely available. Therefore, it could be a transitional period ARI in Switzerland will be turned off on 1 March 2005 on 1 September 2003 and in Germany. The so-called Hinz- trill is not affected by the shutdown.

In and around Hamburg Radio Hamburg sends still (as of August 2012) as the world's last station the ARI identifier from ( area identifier C, FM frequency 103.6 ). Owners of older radios can use the full functionality of ARI here.

In Austria, the ARI transmission was adjusted by 19 May 2008.

In the GDR traffic with ARI was broadcast by Radio DDR I and DDR - traffic radio service, also with a different activation tone. In Czechoslovakia in 1987 (tests as early as 1985 on the transmitter Cukrák in CCIR band) was from 15 January in OIRT band by radio Hvezda (now Český rozhlas Radiožurnál ) the traffic in the broadcast Zelena vlna Hvezdy first along the D1 motorway Prague - Bratislava broadcast. Car radio with ARI decoder produced by the Czechoslovak company Tesla Bratislava.

An introduction of the ARI system in major U.S. cities (among Brooklyn, New York, Long Iceland, New Jersey and the surrounding area ) was carried out by Blaupunkt in cooperation with the local radio stations beginning in 1982, but was not successful. Here, on the one disturbed in the U.S. often aboveground power cable with mounted on poles transformers, on the other hand also incompatibilities with that of the U.S. by FCC regulation to be provided disaster signaling revealed by the used of 1963-1997 Emergency Broadcast System (EBS), or its successor system employed since 1994 Emergency Alert system ( EAS). Also use these tones ( 853 Hz and 960 Hz) in order to support certain notifications by state agencies to the people via radio. The busy towns also wanted a higher number of area IDs, but what is necessary to transfer the frequency spectrum would unduly broadened. Also, there were not enough suppliers to offer a certain variety of ARI -enabled car stereos can.

Hinz- trill

The Hinz trill is transmitted from the broadcasting center ( modulated at the post office transfer point) and triggers the transmitter inaudible announcement identifier, which in turn means that the car radio automatically detects a traffic message as such. That the Hinz- trill is audible, is that modulation lines ( transmission bandwidth of 30 to 15,000 Hz ) should be used for transmission.


The announcement identification DK of the ARI system was switched on by many radio stations by transmitting the so-called Hinz- trill at the transmitter ( ie this does not control about the radio itself). The Hinz trill is an acoustic signal with a center frequency of 2350 Hz ± 1 Hz, which is frequency modulated with a stroke of 123 Hz ± 10 Hz. It turns on at least 1.20 s ± 0.1 s long Hinz trill the announcement identification to a 0.55 s ± 0.05 s long Hinz trill the identifier again. The Hinz trill can also be lowered in level and can be combined with other characteristic melodies of the respective radio station. Lately, use radio stations to control the transmitter no sounds in the audio band more, but transmit this information in separate data channels. This also allow today's standard digital transmission paths between the studio and transmitter. In other countries, different signals were used, for example, in Switzerland two short 15 - kHz tones in the GDR there was only a jingle without control function for the announcement identification ( which was probably switched manually ).

Also, currently (2009) is the Hinz- trill still used by many radio stations as an acoustic signal - even if the use is no longer necessary as technically. So this sound falls into a piece of music, even at very quietly Cut to yet. Technically, the Hinz- trill is despite the exclusive use of RDS messages as Traffic Program still necessary if the RDS encoder are controlled in the individual FM stations yet by the acoustic signal ( ball reception). Due to the ever -richer effect music on the radio, it comes in more and more the error IDs of Hinz- trill. It seeks to change the RDS encoder at the transmitter locations are no longer dependent on the tone control by UECP, then this piece could be eliminated history time traffic program.

Control RDS broadcasts with the Hinz- trill

To use the Hinz- trill to control RDS releases a method " control of the RDS / VRF system by Hinz- trill " in the letter FTZ 175 AB 33 has been defined by the German Post and Telecom. A device that meets the requirements of Telecom, for example, the Rudolph HT090. The supply of the signal is to be made at the transmitter site in front of the post handover amplifier to the line. Also the receiver to switch the RDS encoder at the transmitter site must comply with certain tolerances. The switch- s must be reliably detected in the time range between 1 and 1.4 s, the switch-off must be between 0.45 s and 0.65 s are reliably detected and evaluated. Is considered to be 30 dB below full Mindesteinschaltpegel while the transmitter. If for various reasons (eg line fault ) the off signal is not transmitted or detected, the control signal receiver must (min ± 1) take the TA signal from the transmitter after no more than six minutes.


Named the Hinz- trill is named after its inventor Werner Hinz, who developed it in the DLF in Cologne. The Hinz trill was originally used to control automatic recording devices for traffic announcements at highway rest stops and make the same time in quiet adjusted Radio to Traffic Announcement attention.

At first experimented with a D- major triad. Since this but too often found in pieces of music, it came to false alarms in the recording devices. So Hinz was looking for an unusual dissonant sound that does not occur in music and nature as possible.

Five seconds long Hinz trill to listen to.? / I

The human ear responds to that very frequency-modulated sound very sensitive. Therefore, attention will also increase if no technical support as ARI is used on VHF, for example, when receiving the traffic information on medium and long wave.