Driving through a toll station is a complex issue for an autonomous car. It requires managing the cross flow of vehicles moving randomly through the lanes of the toll station. It also requires guiding the autonomous car in this area where there are no road markings and guiding also the autonomous car along a trajectory which automatically enters the equipped lane which is only three metres wide. Finally, the autonomous car must be in a position to anticipate any unforeseen events that may occur as it crosses through the toll gate.

It was essential to set a specific communication protocol between the toll station infrastructure operated by VINCI Autoroutes and the Citroën C4 Picasso, Groupe PSA’s autonomous car.

• A guidance system has been deployed 500 meters ahead of the Saint-Arnoult toll (towards Paris direction). This allows the autonomous car to follow a pre-recorded trajectory which guides the car to the toll gate lane that has been selected and equipped. The system indicates the path to follow when exiting the gate until the vehicle reaches the motorway, where the car can start again to steer itself thanks to the white lines.

• A pass-through permission is sent to the vehicle, indicating whether the gate is open or not. The infrastructure gives the information to the autonomous car using a Road Side Unit (RSU) positioned 300 meters before the toll station at the edge of the motorway, and connected to the toll station system. The RSU uses the ITS G5 protocol, the reference system for the connected vehicles communication to transmit its data. So far, three lanes of the Saint-Arnoult toll station have been permanently fitted with equipment to safely and quickly transmit the permission to pass relayed by the RSU antenna and receive connected and autonomous vehicles such as the Groupe PSA’s autonomous Citroën C4 Picasso vehicle.

• The toll station’s information system has also been modified to allow autonomous cars to pass through it. It enables a real-time analysis of the availability of the lane and ensures that the conditions allow the vehicle to safely pass through the gate. The permission thus issued is then sent to the autonomous car by the RSU antenna.

• Finally, for this test, the C4 Picasso autonomous vehicle was issued with an electronic toll card enabling it to go through the lanes on autonomous mode.

Mobility is at a crossroads in its history, facing changing behavior and user habits that will deeply change the on-road driving and travelling experience. For the vehicles of tomorrow to be fully autonomous, they will need to be connected to the smart infrastructures that we are currently inventing. Cooperation between car manufacturers and mobility operators is essential from this point of view. Motorways are safe infrastructures and a wonderful testing ground. Tomorrow, they will be the place of this new mobility deployment.

—Pierre Coppey, Chairman of VINCI Autoroutes

This test is the outcome of a joint team work effort made over several months by the Groupe PSA and VINCI Autoroutes.

Crossing through a tollgate in autonomous mode is an important step towards level 4 autonomous driving on motorways. This experimentation shows the potential provided by real-time communications between the vehicle and the road infrastructure. This is the first step in collaboration with VINCI Autoroutes, the purpose being to assess the contribution made by communications with infrastructure for different situations that the autonomous car may encounter on the motorway, such as early warning of roadworks or to facilitate guiding the vehicle to a rest area. This will be the building blocks that are essential in order to complete the current strategy for the autonomous car development within the Groupe PSA.

—Carla Gohin, Director of Innovation at Groupe PSA

The test is part of a broader program to further the cooperation between the autonomous car and the road infrastructure with the aim of achieving fully autonomous driving (level 4 autonomous mode). To this end, the following areas are currently being worked on:

• The safe stop, which consists of pre-defining solutions to automatically guide the vehicle in a car parking area;

• The qualification of traffic conditions for autonomous driving, and the real-time communication of the vehicle. This is particularly significant to enable the autonomous car to travel safely while taking on board any traffic related information (slow traffic, accidents).

This project is consistent with and complementary to other research programs dedicated to the connected and autonomous vehicles, to which both the Groupe PSA and VINCI Autoroutes contribute, such as Scoop@f and C-Roads. In addition, the Groupe PSA and VINCI Autoroutes also play an active role in standardization and knowledge sharing projects, especially through the VEDECOM institute.