With the rapid growth of connected devices in the world, the opportunities for the automobile to take advantage of this newly available information are growing exponentially. By equipping vehicles with technology capable of broadcasting, receiving, and processing pertinent data, the impact on safety, convenience, and mobility is groundbreaking. According to the U.S. Department of Transportation, up to 80% of automobile accidents can be prevented with improved vehicle connectivity. Additionally, it is projected that over 10% of time spent driving is wasted in urban congestion, 12% of urban traffic is created by vehicles looking to park, and up to 17% of urban fuel is wasted at traffic lights when there is no cross-traffic. With connected vehicles, all of these problems can be greatly mitigated.
The connected vehicle market primarily consists of two types of technology: Vehicle-to-Vehicle (V2V) communications between two vehicles and Vehicle-to-Infrastructure (V2I) between a vehicle and a fixed piece of the surrounding infrastructure. Both technologies rely on Dedicated Short Range Communications (DSRC) to transmit and receive information in an automobile. As a natural result of the primary information broadcasted by the DSRC modules (vehicle location, speed, and direction), most of the applications of V2V technologies are focused on collision avoidance, specifically with other vehicles on the road. However, V2V necessarily requires that other vehicles on the road are also connected, otherwise non-communicating vehicles are essentially invisible to connected vehicles without other technology such as radar.
V2I applications, on the other hand, have a broader scope, as they tend to be less immediate or safety-critical. V2I opens up the possibility for more complex data analysis and for information to be stored over time. Contrary to V2V, V2I only requires the infrastructure and the vehicle to be connected, allowing for useful applications immediately without significant market penetration of connected vehicles. Consequently, V2I applications will likely be market ready and in use before V2V applications, thereby leading market adoption of connected vehicles.
By far, the highest concentration of research in V2I applications has focused on Signal Phase and Timing (SPaT). The architecture of SPaT is shown in the figure below. SPaT applications of V2I communications focus on the ability to coordinate driving speeds with traffic light patterns to be able to maximize fuel economy and speed. This communication is useful for multiple reasons. From the infrastructure perspective, by incorporating data from vehicles over time, SPaT patterns can be optimized to provide the optimal traffic flow in high traffic areas. On the consumer side, by optimizing for traffic light patterns, the driver is able to maximize fuel economy by reducing fuel consumption during starts and stops.
Figure 1: Signal Phase and Timing
While the early market development for both V2V and V2I are focused on traffic mitigation and safety, the business models for longer-term growth and success remain undecided. The threshold for the number of vehicles required to be equipped with V2V technology to make the systems viable is an unanswered question, as is the question of who will pay for the infrastructure in the V2I market. The result is a potentially long tail on the “valley of death”. Although DSRC is certainly the focus of development for the market, it’s not hard to imagine a few years of mixed technology as roadside units utilize communication technologies other than just DSRC (including cellular, Radio Frequency Identification (RFID), WiFi, and others) to serve early markets such as smart parking systems, electric vehicle charging equipment information, and fleet vehicle applications.