- 1. Overview
- 2. Etymology
- 3. Cultural Impact
Vehicular communication systems, at their core, are about weaving vehicles and the bits of infrastructure they interact with into a sophisticated tapestry of computer networks . These aren’t your garden-variety networks; they’re dynamic, mobile, and frankly, a bit chaotic. The nodes in this system are the vehicles themselves, along with roadside units—think smart traffic lights, sensors, or digital signage—all acting as conduits for information. This constant exchange, this digital chatter on the move, is designed to do two things: keep people from crashing into each other and prevent them from getting stuck in the kind of traffic jams that make you question all your life choices. The currency of this exchange is data, anything from a heads-up about an impending hazard to the latest intel on traffic flow. To facilitate this, both vehicle-based and roadside units are typically equipped with Dedicated Short-Range Communications (DSRC) devices. These little marvels operate in the 5.9 GHz band, boasting a bandwidth of 75 MHz and a reach of about 300 meters. It’s a slice of the radio spectrum dedicated to keeping things moving and safe, a crucial component within the broader framework of intelligent transportation systems .
History
The idea of cars talking to each other isn’t exactly new; it’s been percolating since the 1970s. Back then, the seeds were sown with projects like the Electronic Route Guidance System (ERGS) in the United States and its counterpart, CACS, in Japan. By the early 1980s, the term inter-vehicle communication (IVC) started to gain traction. Before standards solidified, researchers experimented with a variety of communication methods – lasers, infrared, even radio waves – each with its own set of promises and limitations.
A significant leap forward came with the PATH project in the United States, running from 1986 to 1997. It was a substantial undertaking that pushed the boundaries of what was thought possible in vehicular communication. Across the Atlantic, Europe was making its own strides with the PROMETHEUS project, also active between 1986 and 1995. These foundational efforts paved the way for a global surge in related initiatives. The world saw a proliferation of projects like the Advanced Safety Vehicle (ASV) program, [6] CHAUFFEUR I and II, [7] FleetNet, [8] and CarTALK 2000, [9] each contributing to the evolving landscape of connected vehicles.
The early 2000s saw the introduction of a new term, vehicular ad hoc network (VANET), which essentially adapted the principles of mobile ad hoc networks (MANETs) to the automotive domain. It’s worth noting that the terms VANET and IVC are often used interchangeably, referring to communication between vehicles, whether or not they rely on roadside infrastructure. Some purists argue that IVC strictly denotes direct vehicle-to-vehicle (V2V) connections, but in practice, the lines have blurred. This era also witnessed a flurry of projects across the EU, Japan, and the USA, including ETC, [11] SAFESPOT, [12] PReVENT, [13] COMeSafety, [14] NoW, [15] and IVI, [16] all contributing to the growing body of knowledge and technology.
The nomenclature surrounding vehicular communications is, to put it mildly, a bit of a tangled mess. Different acronyms have emerged, often tied to historical context, the specific technology employed, governing standards, or geographical origin. We see terms like vehicle telematics , DSRC , WAVE, [17] VANET , IoV , 802.11p , ITS-G5, [18] and V2X . Currently, the primary contenders for enabling connected vehicles are cellular-based V2X, leveraging the advancements in 3GPP Release 16, [19] and Wi-Fi based solutions using IEEE 802.11p . However, this doesn’t mean other technologies like Visible Light Communication (VLC), ZigBee , WiMAX , microwave , and mmWave are being shelved; they continue to be active areas of research within vehicular communication.
A multitude of organizations and governmental bodies are actively involved in shaping the standards and regulations for vehicular communication. These include giants like ASTM , IEEE , ETSI , SAE , 3GPP , ARIB , TTC , TTA, [21] CCSA , the ITU , the 5GAA , and ITS America , alongside consortia like ERTICO and ITS Asia-Pacific [22]. The 3GPP is diligently working on specifications for cellular-based V2X, [23] while the IEEE is exploring the future with its study group on Next Generation V2X (NGV), aiming to issue the standard 802.11bd. [24]
Safety Benefits
Let’s be blunt: the primary impetus behind vehicular communication systems is a grim one – saving lives and slashing the exorbitant financial toll of traffic collisions. According to the World Health Organization (WHO), road accidents are a global scourge, claiming approximately 1.2 million lives annually, and representing a quarter of all injury-related deaths. Beyond the fatalities, an estimated 50 million people are injured each year. In 1990, road death was the ninth-leading cause of mortality worldwide. [25] The economic impact is equally staggering; a study by the American Automobile Association (AAA) estimated that car crashes cost the United States a colossal $300 billion per year. [26] Beyond preventing accidents, these systems hold the promise of enabling automated traffic intersection control, [1] fundamentally reshaping how traffic flows.
The tragic reality is that most of these deaths are, in principle, preventable. The U.S. Department of Transportation has highlighted that a significant portion of the 43,000 annual road accident deaths in the US stem from vehicles veering off the road or from incidents at intersections. [27] This figure could be dramatically reduced through the deployment of local warning systems powered by vehicular communications. Imagine a departing vehicle broadcasting its intention to merge, or an arriving car at an intersection sending a preemptive alert to others navigating the same space. The same systems could warn about lane changes or impending traffic jams. [28]
The numbers are stark: a 2010 study by the US National Highway Traffic Safety Administration suggested that vehicular communication systems could potentially prevent up to 79% of all traffic accidents. [29] Furthermore, research indicates that in Western Europe, even a modest 5 km/h reduction in average vehicle speeds could lead to a 25% decrease in fatalities. [30] These statistics underscore the profound potential of connected vehicle technology to create a safer transportation environment.
Vehicle-to-Vehicle
The journey toward robust vehicle-to-vehicle (V2V) communication has been paved with extensive research and countless projects. These efforts have explored a wide spectrum of VANET applications, from critical safety alerts to navigation aids and even law enforcement support. A significant development occurred in December 2016 when the US Department of Transportation proposed draft rules that would mandate V2V communication capabilities in new light-duty vehicles, with a phased implementation. [31] However, the specifics of these regulations have drawn criticism, with some arguing that manufacturers might struggle to translate the broad guidelines into concrete responsibilities under the Federal Motor Vehicle Safety Standards. [31] The prevailing security framework for V2V communications currently relies on Public Key Infrastructure (PKI). [32]
Conflict over Spectrum
The advancement of V2V technology faces a significant hurdle in the form of a contentious battle over radio spectrum. Cable television and other technology firms are vying to reclaim a substantial portion of the radio frequencies currently allocated for V2V communication, intending to repurpose them for high-speed internet services. In the USA , this spectrum was set aside by the government back in 1999, but it has remained largely underutilized. The automotive industry is fiercely advocating for the retention of this spectrum, asserting its critical necessity for V2V applications. The Federal Communications Commission (FCC) has, for the most part, sided with the tech companies, although the National Transportation Safety Board has lent its support to the automotive industry’s position. Internet service providers, eager to utilize the spectrum for their own services, argue that the rise of autonomous cars will render V2V communication obsolete. The US automotive industry has indicated a willingness to share the spectrum, provided that V2V services are not compromised. The FCC, in response, is exploring various spectrum-sharing models and plans to conduct tests on these schemes. [33]
The lack of harmonized spectrum allocation across different regions presents a significant challenge. When governments in various locales support incompatible spectra for V2V communication, it can deter vehicle manufacturers from adopting the technology for certain markets. For instance, in Australia, there is currently no dedicated spectrum reserved for V2V communication, meaning vehicles operating there would be susceptible to interference from non-vehicle communications. [34] The allocated spectra for V2V communications in different regions are as follows:
| Locale | Spectra |
|---|---|
| USA | 5.855–5.905 GHz [34] |
| Europe | 5.855–5.925 GHz [34] |
| Japan | 5.770–5.850 GHz; 715–725 MHz [34] |
| Australia | 5.855–5.925 GHz [35] |
Vehicle-to-Infrastructure
The concept of vehicle-to-infrastructure (V2I) communication has been gaining momentum, with significant research efforts focused on creating smarter, more integrated transportation networks. In 2012, computer scientists at the University of Texas in Austin embarked on developing smart intersections specifically designed for automated vehicles. The vision was to eliminate traditional traffic lights and stop signs, replacing them with sophisticated computer programs that would communicate directly with each vehicle on the road. [36] For autonomous vehicles, seamless connectivity with other ‘devices’ is not merely advantageous; it’s essential for optimal functioning. These vehicles are equipped with advanced communication systems that enable them to interact with other autonomous vehicles and roadside units, exchanging vital information such as real-time updates on road construction or traffic congestion. Furthermore, scientists envision a future where integrated computer programs will manage the navigation of individual autonomous vehicles through intersections, orchestrating their movements with precision. [36] This level of interconnectedness fosters the development of autonomous vehicles that can understand and collaborate with other products and services, such as intersection management systems, within the burgeoning autonomous vehicle market. As more autonomous vehicles adopt these networks, the value proposition strengthens due to the validated information shared and the collective intelligence generated, a phenomenon known as network externalities.
In 2017, researchers from Arizona State University took a significant step forward by developing a 1/10 scale intersection model and proposing an intersection management technique named Crossroads. Their findings demonstrated that Crossroads exhibits remarkable resilience to network delays, both in V2I communication and in the Worst-case Execution Time of the intersection manager itself. [37] Building on this, a more robust approach was introduced in 2018, engineered to withstand not only model mismatches but also external disturbances like wind gusts and road bumps. [38]
Vehicle-to-Everything
The evolution of vehicular communication extends beyond direct vehicle-to-vehicle or vehicle-to-infrastructure links, encompassing a broader concept known as Vehicle-to-Everything (V2X). This umbrella term signifies a comprehensive communication ecosystem where vehicles can interact with a wide array of entities. In November 2019, a compelling demonstration of Cellular V2X (C-V2X) technology, built upon the foundation of 5G, took place on the open streets and a dedicated test track in Turin . [39] During the demonstration, V2V-equipped cars showcased their ability to broadcast messages to following vehicles in the event of sudden braking, providing timely warnings about potentially hazardous situations. Other use cases were also illustrated, including alerting drivers to pedestrians crossing the road. [40]
Key Players
The Intelligent Transportation Society of America (ITSA) plays a crucial role in fostering cooperation between public and private sector organizations involved in advancing intelligent transportation. ITSA articulates its mission through the concept of “vision zero,” aiming to drastically reduce fatal accidents and traffic delays.
Numerous universities are at the forefront of research and development in the field of vehicular ad hoc networks. For example, the University of California , Berkeley , is a key participant in the California Partners for Advanced Transit and Highways (PATH) project, [4] contributing significantly to the collective knowledge and innovation in this domain.