Connected Cars and Machine-to-Machine Networks (V2X)

When Vehicles Stop Being Products and Start Being Nodes

There is a temptation to treat Vehicle-to-Everything as a feature set, the same way people talk about heated seats, adaptive cruise control, or wireless Apple CarPlay. That framing is comfortable, because it keeps V2X small and optional, something you can add to a trim level or postpone until the next product cycle. It is also wrong. V2X is not merely an in-car technology. It is a machine-to-machine network that turns the vehicle into a participant in a larger system—roads, signals, fleets, cities, and increasingly energy infrastructure. Once that shift occurs, the unit of value is no longer “the car.” The unit of value is the interaction between cars and the environment they move through.

This is why connectivity can be more transformative than electrification alone. Electrification changes the powertrain and supply chain, but the vehicle remains a largely self-contained object. V2X changes the operating context. It reshapes how traffic flows, how safety warnings are produced, how infrastructure is managed, how fleets coordinate, and how energy is balanced. It also forces uncomfortable governance questions: who controls the rules of communication, who owns the data, and what trust model allows millions of moving machines to exchange safety-critical messages without collapsing into fraud, spoofing, or surveillance.

The U.S. Department of Transportation has described V2X as communications that include vehicle-to-vehicle, vehicle-to-infrastructure, and vehicle-to-pedestrian, with the potential for major safety and mobility benefits and as a complement to onboard sensors and automation.*1 That “complement” language is a polite way of saying something more radical: the vehicle is becoming a sensor and a broadcaster, and the transportation network is becoming a shared computational layer. The moment you accept that, you stop asking whether V2X matters and start asking how any modern transportation system remains competitive without it.

The Core Idea: Machines Exchanging Meaning, Not Just Signals

At its heart, V2X is not “cars talking.” It is machines exchanging structured messages fast enough and reliably enough to change physical outcomes. The message is the product. The message says, in machine language, “I am here, moving at this speed, in this direction,” or “this light will turn red in three seconds,” or “there is ice ahead,” or “an emergency vehicle is approaching.” Those messages become actionable only if they are standardized, authenticated, interpreted consistently, and delivered within strict latency budgets.

This is why the V2X story is inseparable from standards. A network is only valuable when many participants can join it without bespoke integration. If every city uses a different signal message format and every automaker implements a different trust model, the “network effect” dies before it is born. V2X, more than most automotive technologies, punishes fragmentation.

The message layer in North American deployments has long revolved around SAE J2735, which defines the message set dictionary used for V2X applications such as basic safety messages and infrastructure messages.*2 Even if you never read the standard itself, its existence tells you what the industry had to do: agree on a shared vocabulary so machines can exchange meaning at scale. Without shared meaning, you have radios and noise, not a safety system.

V2X Is Not One Technology: It Is a Stack and a Choice

One of the most confusing parts of the V2X debate is that people speak as if there is a single V2X technology. There isn’t. There are multiple access technologies and multiple regional stacks, and each comes with politics, economics, and path dependency.

In broad terms, there are two families of direct V2X communication that have shaped deployment decisions. One is the Wi-Fi-derived approach historically associated with DSRC in the U.S. and ITS-G5 in Europe, based on IEEE 802.11p lineage. Europe’s ITS-G5 access layer is specified through ETSI standards such as EN 302 663 and updated access-layer work like EN 303 797, reflecting the evolution of the access layer in the ITS-G5 stack.*3 *4 The second family is Cellular V2X, standardized through 3GPP and evolving from LTE-V2X to NR-V2X, using sidelink and cellular interfaces to support V2X services.*5

These are not merely academic alternatives. They influence interoperability, cost, vendor ecosystems, spectrum policy, and upgrade paths. A city that invests in roadside units is, in effect, choosing a long-term communications strategy. An automaker that embeds a chipset is choosing a future dependency. And regulators allocating the 5.9 GHz band are deciding what kind of safety network they want to exist.

The United States provides a dramatic example of how spectrum policy can shape the future. In late 2024, the U.S. Federal Communications Commission adopted rules that further addressed the transition of 5.9 GHz ITS operations toward C-V2X, codifying technical parameters and setting the direction for how the remaining ITS spectrum is used.*6 When a regulator defines technical parameters for a band, it is not only enabling a technology; it is selecting the platform on which future services will be built.

The Hidden Reason V2X Is Hard: Interoperability Is a Human Problem First

The public narrative often frames V2X as an engineering challenge: radios, latency, protocols. But the deeper challenge is cooperation. V2X succeeds only when automakers, suppliers, cities, telecom operators, regulators, and standards bodies align long enough to create critical mass. That kind of alignment is culturally difficult because incentives diverge. Automakers want differentiation, cities want cost control, telecom operators want network value, and regulators want safety outcomes without political backlash.

Europe’s C-ITS efforts highlight how the trust model itself becomes a governance artifact. The European Commission’s delegated work on C-ITS has emphasized enrollment in a security credential management system and the need for a trusted and secure communication framework backed by a PKI-type system.*7 The existence of a trust list manager, certificate policy, and credential governance is a reminder that V2X is not simply about “sending messages.” It is about ensuring that only legitimate participants can send messages that other machines will trust.

In other words, V2X is a system of permissioned speech among machines. That creates a philosophical shift. Roads were historically open systems where “any car can drive.” V2X introduces a layer where “not every message is allowed to count.” The more V2X matters to safety and traffic flow, the more society must decide who is authorized to participate and under what conditions.

Safety Is the First Use Case, but Not the Final One

V2X is often sold on safety, and that is rational. Safety benefits are the easiest to justify politically and morally. A vehicle that can receive a warning about a hard-braking vehicle beyond line of sight gains something sensors alone may miss. A vehicle that can receive signal phase and timing can avoid red-light running scenarios and reduce intersection conflicts.

The U.S. DOT has consistently positioned V2X as a safety and mobility technology with potential benefits on its own and as a complement to vehicle sensors and automated systems.*1 This complementarity matters because it reframes the autonomy debate. V2X does not need full autonomy to be valuable. It can make human drivers safer, and it can make automated driving systems more robust by providing context that cameras and radar can struggle with in edge cases.

Yet the deeper story is that safety is only the opening chapter. Once you build a machine-to-machine network in public space, everything that depends on coordination becomes a candidate for optimization. Traffic flow becomes programmable. Freight routing becomes more synchronized. Emergency response becomes more choreographed. Energy demand becomes more controllable. V2X is the beginning of a world where mobility behaves less like chaotic crowds and more like managed systems.

Smart Intersections: The Quiet Revolution Nobody Films

If you want to understand why V2X matters, ignore the glossy demos and focus on the intersection. Intersections are where urban mobility reveals its limits: conflicts, delays, emissions from idling, and a disproportionate share of severe accidents. An intersection is also where infrastructure can speak in a way that vehicles can use immediately.

Signal Phase and Timing messages, along with map data that describes intersection geometry, allow vehicles to anticipate changes rather than react late. This can smooth braking, reduce harsh acceleration, and create more predictable behavior. The moment vehicles can “see” the intent of the signal, they can act like they are part of the system instead of outsiders guessing it.

This is the kind of change that is hard to market because it is not cinematic. It is not a new body style. It is fewer near-misses, fewer emergency braking events, and fewer wasted minutes. But at scale, this is where V2X becomes a city-level productivity tool. It is not only about the driver’s experience; it is about urban efficiency and public health through reduced congestion and emissions.

Vulnerable Road Users: Why V2X Needs Humility

The phrase “vehicle-to-pedestrian” can sound like a gimmick until you confront what it implies. It implies that a person carrying a phone or wearable becomes part of a safety network. That may save lives. It may also create new vulnerabilities and new inequities.

A system that depends on pedestrians carrying modern devices risks excluding those who do not—children, elderly, low-income communities, and people who deliberately avoid tracking technologies. If V2P is implemented carelessly, it can create a two-tier safety reality where the network protects the visible and ignores the invisible.

This is one reason V2X must be designed with humility. It cannot become an excuse to offload safety responsibility onto users. The ethical frame must remain clear: the system must improve safety broadly, not selectively, and it must not turn “being trackable” into a requirement for being protected.

Interoperability Wars: DSRC, ITS-G5, C-V2X, and the Price of Delay

The history of V2X includes a lesson the industry rarely states plainly: indecision has a cost. When stakeholders fight for a decade over access technologies, deployment stalls, infrastructure ages, and public trust erodes. Meanwhile, road fatalities do not pause because standards bodies are arguing.

Europe’s ITS-G5 standards track shows a mature, layered approach to the access layer and security, with ETSI documents specifying how the access layer operates and how security headers and certificates are structured for ITS communications.*3 *8 The cellular track shows a parallel evolution, with 3GPP describing LTE and NR support for V2X services across sidelink and cellular interfaces.*5 The existence of two mature stacks is not automatically a problem, but it becomes a problem if it prevents interoperable deployment in a given region.

The upgrade question intensifies with next-generation variants. IEEE 802.11bd, positioned as an evolution beyond 802.11p, is discussed as a backward-compatible step toward next-generation V2X for the Wi-Fi-derived family.*9 At the same time, NR-V2X is positioned as the 5G-era evolution of C-V2X, expanding capabilities through new sidelink features.*5 The risk is not that technology evolves. The risk is that deployed assets cannot evolve economically, leaving cities with stranded roadside investments and automakers with inconsistent market requirements.

The strategic reality is that V2X will not “win” through technical superiority alone. It will win through deployment momentum, governance clarity, and credible interoperability.

Trust Models and PKI: The Unsexy Infrastructure That Makes Everything Else Real

The most important part of V2X is often the least discussed: trust. If a car receives a hazard warning, how does it know the warning is real? If an attacker can inject false messages, V2X becomes a weapon: phantom hazards, false emergency vehicle claims, traffic manipulation, or coordinated disruption.

This is why modern V2X architectures lean on certificate-based trust models, with signed messages and credential management systems. ETSI’s security specifications for ITS communications describe security header and certificate formats that support trusted message exchange while addressing privacy considerations.*8 The European C-ITS framework has gone further into governance, including a security credential management system, trust list management, and certificate policy structures designed to ensure only trusted parties can participate.*7 *10

Trust in V2X is not only cryptographic; it is institutional. Someone must operate the root of trust, define policies, audit compliance, revoke bad actors, and manage cross-border compatibility. This is where V2X becomes more like aviation or payments than like consumer electronics. A safety network cannot rely on informal trust.

The opportunity here is that once a trust infrastructure exists, it can support more than safety. It can support billing, access control, fleet privileges, emergency corridors, and energy services. But the warning is also clear: if trust governance is captured by narrow interests or implemented without transparency, it can become a tool of exclusion.

Data Governance: When “Smarter Cities” Meet Privacy Reality

V2X generates data that is both valuable and sensitive. Location and trajectory data can reveal a person’s habits, workplace, home, religious attendance, medical routines, and personal relationships. Even if messages are pseudonymized, re-identification risks can emerge when data is aggregated across systems.

This is where the V2X debate must grow up. It is not enough to say “we will anonymize.” Governance must address purpose limitation, retention limits, access control, and transparency. The NIST Privacy Framework was designed to help organizations manage privacy risk while enabling innovation, emphasizing that privacy risk is not only legal compliance but a broader risk management discipline.*11 That mindset is essential for V2X, because the system’s legitimacy will depend on the public believing that mobility data is not becoming a permanent surveillance stream.

The governance challenge deepens when vehicles expose data through standardized web services. The ISO “extended vehicle” concept, described through ISO 20078, aims to ensure interoperable web services for accessing vehicle resources, including resource identifiers and categories that can include personal resources.*12 If the vehicle becomes a web platform, then data governance becomes inseparable from platform governance. Who is allowed to access what resource? Under what authorization? With what oversight? Those questions define whether V2X becomes a trusted public utility or a contested data battleground.

V2X and the Energy Grid: The Moment Mobility Becomes Infrastructure

When people say “vehicles communicating with power grids,” they are pointing at a change that can rival the original arrival of the automobile. An electric vehicle is not only transportation. It is a mobile battery and a controllable electrical load. When millions of such loads connect to the grid, the difference between chaos and stability becomes communication and coordination.

The U.S. Department of Energy has described vehicle-grid integration as the intelligent integration of EVs with the electric grid, enabling vehicles to act as controllable load and mobile storage capable of providing grid services.*13 This is not theoretical. It is a policy and engineering priority because EV adoption changes demand curves, peak loads, and local distribution constraints.

Standards are the backbone here as well. ISO 15118 specifies communication between electric vehicles and charging equipment, and newer parts such as ISO 15118-20 are designed to support bidirectional power transfer use cases that align with vehicle-to-grid functionality.*14 If V2X is about vehicles speaking to roads, V2G is about vehicles speaking to energy markets and grid operators, often through chargers and backend systems. This expands the stakeholder ecosystem again: utilities, regulators, charging network operators, and cybersecurity authorities.

On the charger-management side, the Open Charge Point Protocol is designed to provide a uniform method of communication between charge points and central systems, supporting multi-vendor interoperability in charging infrastructure.*15 This matters because grid coordination depends on the ability to manage large charging networks reliably. Without open interoperability, grid integration becomes a patchwork of proprietary systems, which is precisely how large systems fail when stressed.

The transformational insight is that V2X is not only about road safety. It is about system-level coordination in two critical infrastructures at once: transportation and energy. That is why the stakes are so high and why governance cannot be left to ad hoc industry alliances alone.

The Cybersecurity Shadow: A Networked Safety System Must Assume Attackers

If V2X becomes important, it becomes targetable. That is not cynicism; it is physics of incentives. A safety network that influences vehicle behavior and traffic flow is valuable to attackers who want disruption, fraud, or leverage. That is why security standards and credential management systems are not optional accessories; they are foundational requirements.*7 *8

But cybersecurity in V2X is not only about cryptography. It is also about operational resilience. How quickly can compromised certificates be revoked? How are anomalies detected? How are roadside units maintained and patched? How do cities manage vendor dependencies? The truth is that most municipalities are not staffed like cybersecurity operations centers. If V2X infrastructure is deployed without operational security maturity, it will become a weak link that undermines trust.

This is where the automotive and city domains collide culturally. Automakers, even when imperfect, have safety and quality cultures. Many cities have procurement cultures designed for roads and construction, not for cryptographic credential governance. If V2X is to scale, cities will need new operational capabilities, or they will need trusted operators who can run credential and security infrastructure transparently and accountably.

The Business Reality: V2X Rewards Coordination More Than Hardware

Electrification rewards hardware supply chains and manufacturing scale. V2X rewards coordination, governance, and platform economics. The winners will not only be those who make the best radios. They will be those who can orchestrate ecosystems: automakers aligning with cities, fleets aligning with utilities, standards bodies aligning with regulators.

This creates strategic opportunities for companies that think like system integrators rather than product vendors. Fleet operators can become early adopters because they control many vehicles and have clear economic incentives in safety and efficiency. Cities can justify investments when V2X reduces congestion and improves emergency response outcomes. Utilities can justify investments when smart charging reduces peak load costs and defers grid upgrades.*13

At the same time, the business risks are real. If standards remain fragmented, deployments can become stranded. If governance is mishandled, public trust can collapse. If data access becomes exploitative, regulators can intervene aggressively. V2X is a technology, but it is also a legitimacy project.

Real-World Deployment: Why “Pilot Success” Often Lies

V2X is full of pilots that look successful because they operate under controlled conditions with engaged stakeholders. The problem is that pilots often avoid the hardest parts: long-term maintenance, procurement cycles, cross-vendor interoperability, credential lifecycle management, and the slow grind of scaling to thousands of intersections.

The difference between a pilot and a system is not the radio. It is the institution. A real V2X deployment requires stable funding, governance continuity beyond election cycles, vendor accountability, standardized interfaces, and measurable outcomes. When those conditions exist, V2X becomes a compounding asset. When they do not, V2X becomes another smart-city promise that dies in maintenance budgets.

This is why standards and policy work matter so much. ETSI’s ITS-G5 access-layer specifications, the security standards for ITS communications, 3GPP’s V2X standardization work, and national policy frameworks are all attempts to reduce the friction of scaling.*3 *5 *8 The lesson is simple: if you want the network effect, you must invest in the unglamorous rules that make networks work.

What Automakers Should Do Now: Build for Interoperability, Not Demonstrations

If you are an automaker, the most damaging mistake you can make is to treat V2X as a marketing demo rather than a durable capability. Durable capability means you implement standardized message sets properly, you design for certificate-based trust models, and you plan for lifecycle updates and compliance requirements that are becoming more formalized.*2 *7 *8

Durable capability also means you separate “connectivity for convenience” from “connectivity for safety.” A vehicle app that unlocks doors is not governed like a safety system. V2X safety messages demand stronger assurance, clearer trust roots, and more conservative behavior under uncertainty. If your internal culture treats all connectivity as the same category, you will either under-secure safety functions or over-complicate consumer functions.

You should also confront a strategic reality: V2X will increasingly be judged by outcomes, not by presence. It will not be enough to say “our cars are V2X-capable.” The real question will be whether your implementation works across cities, across suppliers, and across borders. That is why aligning to recognized standards and trust models is not a bureaucratic burden; it is a competitive strategy.

What Cities and Road Authorities Should Do Now: Procure Governance, Not Just Hardware

If you are a city or road authority, your risk is even sharper. You will be tempted to buy roadside units like you buy traffic cabinets: lowest bidder, hardware specs, and installation timelines. That approach will fail because V2X is not only hardware. It is credential governance, security operations, update management, and interoperability testing.

European C-ITS work demonstrates that trust models require specific roles and published trust artifacts, not vague promises.*10 If you procure V2X infrastructure, you must procure the ability to operate it securely for a decade, including certificate enrollment, revocation, incident response, and vendor patching commitments. Otherwise, you will deploy a system that becomes less safe over time.

Cities also need to demand open standards alignment. If a vendor offers a proprietary shortcut, you may win a pilot but lose the future. The moment another vendor enters, your system becomes an integration nightmare. The real economic value of V2X comes from being able to add participants cheaply. That is the network effect. Proprietary lock-in kills it.

What Utilities and Charging Networks Should Do Now: Treat Mobility as a Grid Resource

Utilities are often conservative for good reasons: reliability is sacred. But EV adoption forces utilities into a new world where transportation becomes a major load category and a potential storage resource. Vehicle-grid integration frameworks emphasize that EVs can be controllable load and storage, supporting grid services and changing the relationship between transportation and electricity.*13

To make that real, utilities and charging networks need interoperability at multiple layers. Vehicle-to-charger communication standards like ISO 15118 and charger-to-backend standards like OCPP enable the kind of coordination that makes managed charging and bidirectional services feasible.*14 *15 Without such standards, coordination becomes a bespoke integration project for every vendor, which is exactly how scale collapses.

The strategic warning is this: if grid integration is done poorly, EVs can become a political liability, blamed for outages, peak price spikes, and local transformer failures. If grid integration is done well, EVs become a stabilizing asset. Communication and governance are what separate those futures.

The Real Transformation: V2X Turns Mobility Into a Coordinated System

Electrification changes what powers the vehicle. V2X changes how the vehicle belongs to the world around it. That is why it can be more transformative than electrification alone. It moves the automobile from being an independent actor to being a cooperative participant in a shared system.

In the coming decade, the most advanced cities will not only have EVs. They will have intersections that broadcast intent, fleets that coordinate routes with infrastructure, emergency corridors that are dynamically managed, and charging networks that respond intelligently to grid conditions. The places that achieve this will look safer, smoother, and more resilient, not because their roads are magically wider, but because their mobility system behaves like a system.

The cost of reaching that future is not only technology. It is discipline: standards discipline, governance discipline, security discipline, and institutional discipline. V2X is a connectivity wave, but it is also a maturity test. The winners will be the societies and companies that treat machine-to-machine networks as critical infrastructure, not as a gadget.

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References

*1 U.S. Department of Transportation. (2019, June 14). Vehicle-to-Everything (V2X) Communications. https://www.transportation.gov/v2x

*2 Architecture Reference for Cooperative and Intelligent Transportation (ARC-IT). (n.d.). SAE J2735 DSRC Message Set. https://www.arc-it.net/html/standards/standard17.html

*3 European Telecommunications Standards Institute. (2012). EN 302 663 V1.2.0: Intelligent Transport Systems (ITS); ITS-G5 Access layer specification for Intelligent Transport Systems operating in the 5 GHz frequency band. https://www.etsi.org/deliver/etsi_en/302600_302699/302663/01.02.00_20/en_302663v010200a.pdf

*4 European Telecommunications Standards Institute. (2024). EN 303 797 V2.1.1: Intelligent Transport Systems (ITS); ITS-G5 Access layer specification; Release 2. https://www.etsi.org/deliver/etsi_en/303700_303799/303797/02.01.01_60/en_303797v020101p.pdf

*5 European Telecommunications Standards Institute. (2020). ETSI TR 137 985 V16.0.0: LTE; 5G; Overall description of V2X services and related RAN aspects. https://www.etsi.org/deliver/etsi_tr/137900_137999/137985/16.00.00_60/tr_137985v160000p.pdf

*6 Federal Communications Commission. (2024, November 21). FCC-24-123A1: Second Report and Order (5.9 GHz ITS; C-V2X technical parameters). https://docs.fcc.gov/public/attachments/FCC-24-123A1.pdf

*7 European Parliament and Council. (2019). Commission Delegated Regulation on Cooperative Intelligent Transport Systems (C-ITS) (security credential management system and related provisions). https://www.europarl.europa.eu/cmsdata/161226/Delegated%20Regulation%20C-ITS.pdf

*8 European Telecommunications Standards Institute. (2021). ETSI TS 103 097 V2.1.1: Intelligent Transport Systems (ITS); Security; Security header and certificate formats; Release 2. https://www.etsi.org/deliver/etsi_ts/103000_103099/103097/02.01.01_60/ts_103097v020101p.pdf

*9 CAR 2 CAR Communication Consortium. (2023). Next Generation V2X – IEEE 802.11bd as fully backward compatible evolution of IEEE 802.11p. https://www.car-2-car.org/fileadmin/documents/General_Documents/C2CCC_WP_2098_IEEE_802.11bd_TheV2XEvolution_V1.0.pdf

*10 European Commission Joint Research Centre. (n.d.). C-ITS Point of Contact (CPOC) public interface of the EU C-ITS Security Credential Management System. https://cpoc.jrc.ec.europa.eu/

*11 National Institute of Standards and Technology. (n.d.). Privacy Framework. https://www.nist.gov/privacy-framework

*12 International Organization for Standardization. (2021). ISO 20078-1: Road vehicles — Extended vehicle (ExVe) web services — Part 1: Content and definitions. https://www.iso.org/standard/80183.html

*13 U.S. Department of Energy. (2025). Vehicle Grid Integration Assessment Report. https://www.energy.gov/sites/default/files/2025-01/Vehicle_Grid_Integration_Asseessment_Report_01162025.pdf

*14 International Organization for Standardization. (2022). ISO 15118-20: Road vehicles — Vehicle to grid communication interface — Part 20. https://www.iso.org/standard/77845.html

*15 Open Charge Alliance. (n.d.). OCPP 2.0.1. https://openchargealliance.org/protocols/ocpp-protocols/ocpp-2-0-1/