The radio transponder, also known as a tag, can be obtained from the office of the toll plazas, authorized major banks, mobile points of sales and on the internet as well, after signing an agreement. The tag is issued for a specific licence plate and so for a specific vehicle category. It cannot be transferred without notice to the provider. The tags slightly differ in size and form depending on the provider, and can be replaced within the guarantee period, which varies from three to five years. Before using OGS, the tag's account has to be credited. The OGS system involves the fixing of the tag on the inside of the vehicle's windshield, mostly behind the rear-view mirror. However, on some car brands, the tag has to be attached on the inside base of the windshield. At the toll plaza, the vehicle has to drive to a toll booth on the OGS-only assigned lane. OGS lanes are always leftmost passing lanes, and they are designated at some distance before the toll plaza. However, there are also additional OGS booths on the right side of toll plazas dedicated to heavy vehicles. The booth is marked with an OGS-sign at the top. A flashing green light at the top signals its usability. The battery-driven tag communicates with the reader device built into the toll collection equipment at the toll booth as the vehicle passes through. It is not required that the vehicle stop. However, a speed limit of is recommended to avoid accidents before the booth. Vehicles are classified for toll purposes in five categories based on the wheelbase and the number of axles. If the number of axles of a vehicle is less than the maximum number of axles -because some axles of a truck are lifted up or a tractor is running without its trailer-, the integrated automated vehicle classification system changes the vehicle category read in to the actual one during the passage allowing a lower toll tariff. The bridge toll is fixed for each vehicle category, and is charged only once in eastward direction on the two bridges in Istanbul. The road toll is rated further depending on the distance driven between the entry and the exit of motorway for each vehicle category. For this reason, a signal has to be initiated on the OGS-lane by entering the motorway. OGS users benefit from 20% discount at all toll roads and bridges in Turkey. The tag can sound in two different modes: One beep indicates that tolling was successful. Four consecutive beeps mean insufficient credit on the tag's account. If the tag does not sound at the next three or four passes, it is most likely that either the tag is out of order or it is being used in an incorrect way. In this case, the tag has to be tested by the highway authority, since untolled passes more than ten times is absolutely not allowed. At the toll booth's exit, an electronic display summarizes the tolling process showing one of the following eight messages:
GÜLE GÜLE : Tolling was successful. Vehicle category and toll amount are shown also.
KREDİ AZ : Amount of credit at tag's bank account is insufficient. Payment onto account is needed.
KAÇIŞ : Vehicle without tag or with unreadable tag. Refrain from further passes.
KARA LST : Tag on blacklist. Do not pass.
S. FARKLI Vehicle's category on the tag does not match the actual category. Do not pass.
U DÖNÜŞÜ : Vehicle performed U-turn by exiting the same toll station it entered. Vehicle is tolled at the maximum distance tariff.
GİRİŞ YOK : Vehicle's tag has no information about entry station. Vehicle is tolled at the maximum distance tariff.
SÜRE DOLU : Vehicle overstayed at the motorway. Vehicle is tolled at the maximum distance tariff.
TANIMSIZ : Improper tag. Do not pass.
Violation
In order to allow an uninterrupted passage, there are no gate arms at toll booths on OGS-lanes. If the tolling process is not successful, a lamp under the electronic message display at the exit of the OGS booth turns yellow for a short time, and the display shows the message "CEZALI GEÇİŞ, KAÇIŞ" adding vehicle's category and the amount of fine. Further, the driver is warned by a loud electronic horn at the booth, and the vehicle is photographed as well for evidence. In the case of an unmatched vehicle category, the tag's account is charged with the actual category. However, the driver is warned by the booth horn, and the vehicle is photographed. The tag's account is charged with an additional fine of the amount of double the maximum toll for each violation. The vehicle is blacklisted when this type of violation occurs more than ten times. Vehicles on the blacklist or vehicles without a tag or with another vehicle's tag are charged with a fine as high as eleven times the toll amount. Vehicle owners or drivers can query information about their violation online or at a call center. Payment of the fine within 15 days following the violation notice's receipt enables 25% discount according to Turkish law.
