OGS was an electronic toll collection system of RFID transponder type available on toll roads and toll bridges in Turkey. The system was adopted to avoid traffic congestion at toll plazas. The successor to OGS is the HGS system of RFID tag type implemented later on at the same toll plazas.

HGS is an electronic toll collection system of radio-frequency identification (RFID) transponder type available on toll roads and toll bridges in Turkey. It is obtainable in a sticker or card form. Payment is handled by antenna on the toll booth, which collect money from the account associated with the tag. Additionally, smart cameras are used to detect the license plate and class of the vehicle. Despite these features, HGS is more cost-efficient compared to the OGS system.