Test driving a Nissan automated driving car. An important issue for automated vehicles is the Vehicle to Infrastructure (V2I) integration.

I tried Nissan's latest version automated driving car in Odaiba, Japan area where the 45th Tokyo Motor Show (open to the public from October 27th - November 5th, 2017) had been held and just finished.
I had previously tried Nissan's automated driving vehicle on normal roads in the Odaiba area two years ago. This time it was a demonstration using a more complicated driving situation, such as automatic lane change on the capital express ways. I exchanged opinions on "ITS and big data" with the director in charge of Nissan advanced automated driving development during the test drive.

The director considers "Infrastructure” (V2I Communication: Vehicle to Infrastructure) as the most important issue for the practical use of advanced automated driving". Currently a typical example of road-vehicle communication is ETC (automatic toll collection system). This communication is done using the DSRC (Dedicated Short Range Communication) 5.8 GHz band. I have mentioned in a previous article that ETC 2.0 has better service than the earlier, normal ETC from 2015. The ETC 2.0 was also promoted at the 45th Tokyo Motor Show. However regarding road-to-vehicle communication, Nissan mentioned "further strengthening is necessary" and it does not include ETC 2.0.

 "The importance of connected car" is a common recognition among those related to the automated driving car companies

For automated car operations the most important thing is "safety". This “safety” requires a safer driving level than human drivers can achieve with the goal being zero accidents or "ultimate safety". Actually people understand zero accidents may be impossible, but still seek a perfect automated driving experience.
In order to guarantee safety during automated driving, many kinds of sensors are mounted on the automated driving vehicle. For example in the case of the Nissan's automated driving car that I tested this time, it has a camera, a laser scanner (rider), a millimeter wave radar in 77 GHz band for long distance, a 24 GHz band for medium distance, and an ultrasonic sensor (sonar) for short distance.
However the distance that can be sensed is a few hundred meters in the front direction of the vehicle with a smaller sensed distance behind the vehicle. In the future attempts to improve the sensor's performance and increase the distance that can be sensed together are not likely to be accomplished.
This policy is not only anticipated by Nissan, but also by other Japanese companies such as Toyota and western companies like Daimler and GM. Information sensed ahead by hundreds of meters will be a possible technical limitation of the "Connected Car".

 Information on the surrounding vehicles is not dependent on the V2V (vehicle to vehicle) communication but instead on the V2I (vehicle to infrastructure) communication.

A connected car is a system in which data is exchanged between the car and the outside infrastructure using communication from the car to the cloud, or from the cloud to the car.
In the automated driving system it transmits information such as weather, accident, construction, congestion, etc. to vehicle end, allowing the automated driving vehicle to look ahead at the road situation. This kind of utilization of big data method is already being used by ETC 2.0. It is called a “prediction of running”.

Meanwhile during the test drive in Nissan's automated driving vehicle I felt anxiety about sensing a car approaching diagonally from the rear when joining the main line after passing tollgate of the capital express way. If there is a concrete wall or pole between the main line, near the confluence point, the sensing of the vehicle may not read the exact position of the rear vehicle. To prevent this risk the live information confirms the positional relationship with the car near the vehicle using DSRC however 700 MHz bandwidth is needed.

Some people may think only data exchanging of V2V (vehicle to vehicle) is needed, but actually V2I (vehicle to infrastructure) communication is also required. Obviously V2I is slower than V2V on the data analysis and data transmission, but it is expected that some of these technical issues will be solved by the next generation communication method called 5G which will begin to spread in early 2020s.
In summary what I felt thorough the driving demonstration of the automated driving car is that there are still many issues to resolve before the automated driving level 3 or level 4 with zero accidents can be achieved.