A regional planning agency spent part of 2019 and 2020 sketching out a concept that, at the time, seemed like a reasonable bet on where connected-vehicle technology was headed: roadside units broadcasting real-time curb status — loading zone occupied, commercial vehicle parking available, construction closure ahead — directly to equipped trucks and transit vehicles approaching a congested downtown corridor. It was the kind of V2I (vehicle-to-infrastructure) application that showed up in federal connected-vehicle pilot documentation for years, built on the assumption that Dedicated Short-Range Communications, or DSRC, would remain the federally reserved radio technology carrying that signal. Two years and one federal court ruling later, that assumption is no longer safe to make. The spectrum band the whole concept depended on has been split, DSRC has lost its reserved federal home, and any planning office still holding a V2I curb-signaling concept on the shelf needs to understand exactly what changed this year — and what it didn’t.

What the FCC Actually Did to the 5.9 GHz Band

The root of this goes back to November 2020, when the Federal Communications Commission adopted a First Report and Order that fundamentally restructured the 5.9 GHz band (5.850–5.925 GHz) — spectrum the transportation sector had held in reserve for intelligent transportation system (ITS) use since 1999, under the DSRC standard, but had never built out at meaningful scale. The FCC’s order split that 75 megahertz in two: the lower 45 MHz was reallocated to unlicensed use, primarily for Wi-Fi, and the upper 30 MHz was retained for ITS — but restricted to Cellular Vehicle-to-Everything (C-V2X) technology rather than DSRC. In practical terms, the order didn’t just shrink the ITS allocation; it eliminated DSRC’s federally reserved spectrum home entirely, betting instead on a cellular-based V2X standard that most of the connected-vehicle industry — automakers included — had already been migrating toward.

Transportation-sector groups pushed back hard. The Intelligent Transportation Society of America (ITS America) and AASHTO petitioned for review, arguing the FCC’s process was arbitrary and that the agency had disregarded transportation-safety expertise built up over two decades of DSRC-focused planning and pilot deployment. That challenge worked its way through the D.C. Circuit Court of Appeals, and on August 12, 2022, the court ruled against the petitioners, upholding the FCC’s reallocation in full. ITS America and AASHTO called the outcome “a blow to transportation safety” in their public response. Whatever one makes of that framing, the practical effect for anyone planning V2I infrastructure is now settled at the regulatory level, not just proposed: DSRC has no reserved spectrum path forward in the United States, and C-V2X is the only ITS-band technology with a durable home in the 30 MHz that remains. The FCC’s own Dedicated Short-Range Communications (DSRC) Service program page lays out the service’s history and the band’s current status for anyone verifying this directly.

Why This Matters to Curb and Parking Planning at All

It’s fair to ask why a spectrum dispute between wireless carriers, automakers, and state DOTs should register on a parking or curb-management planning desk. The honest answer is that it mostly hasn’t yet — deployed, revenue-generating curb and parking applications running over V2I broadcast are essentially nonexistent as of this year. But the concept has had real currency in ITS planning circles for longer than most people in the parking industry may realize. SAE International’s J2735 standard, which defines the message set and data dictionary that V2X-equipped vehicles and roadside units use to exchange structured information — signal phase and timing, work zone data, traveler information — got its latest scheduled revision this month, published as J2735_202211. That standard has long included traveler-information and roadway-geometry message types broad enough to carry curb-lane status data, even though no message type in the dictionary is purpose-built and labeled specifically for “parking availability” the way SPaT is purpose-built for signal timing. The capability to carry that kind of data has existed in the standards conversation for years; deployment has not followed.

That gap is exactly why the DSRC-to-C-V2X transition matters now rather than as an abstract technology-policy footnote. Any planning office, university transportation center, or vendor that had penciled in a DSRC roadside-unit deployment as the delivery mechanism for a future curb-signaling pilot has to throw out that hardware assumption. C-V2X and DSRC are not interchangeable at the radio layer — they use different modulation and access schemes — so a roadside unit built for one cannot simply have its firmware updated to speak the other. Anyone with DSRC hardware sitting in a grant-funded pilot, or budgeted in a coming capital cycle, needs to treat that spectrum decision as final and revisit the procurement plan around C-V2X-capable equipment instead.

What Happened to the Legacy DSRC Pilots?

The clearest evidence of how this transition is actually playing out sits inside USDOT’s own Connected Vehicle Pilot Deployment Program, which is worth understanding because it’s the closest thing the country has to real-world data on V2I infrastructure at scale. In September 2015, USDOT selected three sites — New York City, Wyoming, and Tampa — for a combined roughly $45 million in federal funding to deploy connected-vehicle applications and technology. New York City’s deployment alone equipped 470 roadside units and around 3,000 vehicles with V2V and V2I communications gear, almost all of it built on DSRC, since C-V2X commercial hardware barely existed when those pilots were designed. Wyoming’s site strung roughly 75 roadside units along 402 miles of Interstate 80, focused on truck-relevant applications like work zone warnings, weather-responsive speed advisories, and forward collision alerts — the same category of use case a curb-status or freight-parking-availability broadcast would eventually have slotted into.

Since the FCC’s 2020 order, Wyoming’s program has moved into a follow-on phase explicitly built around replacing its DSRC roadside devices with C-V2X equipment — one of the only real-world examples of a state DOT actively executing this exact hardware migration on infrastructure that was already in the ground. That’s a useful data point for any parking or curb-management planning office watching from the sidelines: even a well-funded, federally supported pilot with years of DSRC operating history is now spending additional program cycles simply swapping radios, not adding new applications. A parking-technology pilot starting from scratch today has the advantage of skipping that sunk cost — but only if it avoids repeating the mistake of procuring DSRC-based gear now.

Is C-V2X Actually Ready to Carry Curb or Parking Data Today?

Not in any deployed, operational sense — and it’s worth being direct about that rather than overselling where the technology stands. C-V2X commercial roadside-unit and onboard-unit hardware exists and is shipping, largely driven by automotive safety use cases (intersection movement assist, forward collision warning) rather than parking or curb applications. The near-term connected-curb and parking-availability data pipelines that are actually operating today — the ones behind apps like SpotHero, ParkMobile, or municipal parking-guidance systems, and behind the Curb Data Specification work some cities have adopted for loading-zone management — run over ordinary cellular data networks and web APIs, not direct short-range V2I broadcast. That’s a meaningfully different architecture: a phone or connected head unit pulling data from a cloud API is not the same thing as a vehicle receiving a broadcast message from a roadside unit as it approaches a block.

The honest framing for a planning office is that V2I-delivered curb and parking data remains a standards-and-concept-level capability, not an operating one. SAE’s message-set work keeps the door open for it, and the spectrum question that would have made or broken any future deployment has now been resolved in C-V2X’s favor. But nobody should treat that as a signal that V2I curb broadcast is imminent. The practical, revenue-generating path for connected-curb data delivery today, and very likely for the next several years, runs through cellular APIs and third-party data platforms — the same channels most cities are already using — not through roadside radio hardware.

What Should a Planning Office Do With a V2I Curb Concept Right Now?

A few concrete takeaways follow from where things actually stand at the end of 2022. First, any capital plan or grant application that specifies DSRC roadside hardware for a parking or curb-signaling pilot needs to be corrected before it goes out the door; that architecture no longer has a durable regulatory home, and a reviewer familiar with the FCC order will flag it. Second, if a V2I curb-signaling concept is genuinely worth pursuing, it belongs in the same conversation as a jurisdiction’s broader connected-vehicle and ITS planning — coordinating with the state DOT’s ITS office or regional MPO, most of which are already tracking the C-V2X transition for corridor safety applications, rather than standing up parking-specific radio infrastructure in isolation. Third, for the immediate term, curb and parking data delivery investment is better spent on cellular-API integration, data standardization (Curb Data Specification-style feeds), and the operational discipline of keeping that data accurate — the piece of this that actually determines whether a program works, regardless of which radio eventually carries it. This is also the same corridor of federal activity where the FY2022 ATCMTD grant round funded a C-V2X deployment on the Atlantic City Expressway, one of ten projects nationally, which gives planning offices a live example to watch rather than a hypothetical.

None of this means V2I-delivered curb data is a dead end. The spectrum fight that would have made the whole question moot has been resolved, the message-set standards keep evolving, and automaker C-V2X hardware volumes will keep climbing for safety reasons that have nothing to do with parking. But for a planning office weighing where to put scarce technology-pilot dollars in the next budget cycle, the realistic answer is that the plumbing already in place — cellular networks, structured data feeds, and the growing base of curb-management platforms built on them — is where a parking or curb-signaling investment pays off today. V2I is the longer-horizon layer to keep an eye on, not the one to build a near-term program around.

Frequently Asked Questions

What is the difference between DSRC and C-V2X for connected-vehicle applications?

Both are short-range wireless technologies for vehicle-to-vehicle and vehicle-to-infrastructure communication, but they use incompatible radio designs — DSRC is based on Wi-Fi-derived protocols, while C-V2X is built on cellular network standards. A device built for one cannot communicate with a device built for the other without new hardware, which is why the FCC’s spectrum decision effectively forces a hardware transition rather than a software update.

Did the August 2022 court ruling ban DSRC outright?

Not immediately or absolutely, but it upheld the FCC’s decision to restrict the ITS-reserved portion of the 5.9 GHz band to C-V2X rather than DSRC going forward. The ruling closed off the legal challenge that DSRC advocates had pursued since the FCC’s 2020 order, removing the main remaining path for DSRC to retain a reserved federal spectrum home in that band.

Is there a real, operating example of a parking or curb application using V2I broadcast today?

Not at meaningful deployment scale as of this writing. Standards work — including SAE’s J2735 message-set dictionary — supports the concept, and USDOT’s Connected Vehicle Pilot sites have tested related roadway-status broadcast applications, but curb and parking-availability data delivered to drivers today runs almost entirely over cellular apps and APIs rather than direct roadside V2I broadcast.

Should a city planning a curb-management pilot buy DSRC hardware to save money in the short term?

No. DSRC roadside hardware no longer has a durable federal spectrum allocation to operate in following the FCC’s order and the D.C. Circuit’s August 2022 ruling, so equipment procured on that standard carries real obsolescence risk. Any near-term hardware investment for V2I-style applications should be scoped around C-V2X compatibility, and most curb-data needs today are better served by cellular-based data integration than by roadside radio hardware at all.