Transportation technology startup GeoToll is developing a tolling system that automatically takes payment as a vehicle passes a toll gantry, using a combination of NFC, RFID and GPS.

The new system uses GPS to wake the dedicated GeoToll app on a driver's smartphone when approaching a toll plaza, while the RFID chip embedded in a standard toll tag fixed to the back of the user's smartphone is read as usual by the toll gate or gantry when a vehicle passes through.

NFC is then used to allow the toll tag to communicate with the smartphone, allowing payment to be taken from the user's prepaid account and for invoicing by email. Users can also see a record of tolls paid with the app.

The advantage of the GeoToll system, says the company, is that the same account can be used across multiple vehicles and even rental cars.

GeoToll says it is using the popular 6C toll tag which is now available with a built-in NFC side, and a special omnidirectional RFID antenna which should mitigate any issues over where the smartphone is kept within the vehicle — toll tags are usually stuck to the car windscreen and therefore have a line of sight connection to toll reader gantries, but a smartphone could be mounted on the dash or hidden in a driver's pocket or handbag.

GeoToll CEO Timothy McGuckin also told NFC World "We're working on a multi-protocol solution too, to enable national use across the four to five regional toll standards in the US."

The company adds that there is no rollout date set yet, and more tests are to be carried out across the US this year.