Updated 2026-10-09
Who this is for
A transportation lab that wants to test an application against real messages, a graduate student building a SPaT-based eco-driving model, a city that wants its first three connected intersections, a state DOT evaluating snow-plow priority, a vendor integration team preparing for a plugfest. The portal is free for all of them; everything below can be done with a free account, and the parts that need an agency's network or a fleet are where ITS Roads offers a managed instance.
End to end
| Stage | What to do | Portal tools | Read |
|---|---|---|---|
| 1. Plan | Pick the application (SPaT, priority, work zone, VRU, perception), the sites, the fleet, the measures of effectiveness, and the data you will keep | Standards, deployment resources | |
| 2. MAP and SPaT | Author the MAP in the builder from survey or imagery; get the controller's phase and overlap table; configure the SPaT generator; verify the binding | map builder, creator, decoder | MAP, SPaT, MAP to SPaT, how signal timing works |
| 3. RSU setup | Register the RSUs, test SNMPv3 connectivity, configure radios and time source, set forwarding rows | My RSUs, RSU map | NTCIP 1218 push, capturing messages |
| 4. SCMS | Enroll RSUs and vehicles, obtain application certificates for the PSIDs you will send, check certificate health over SNMP | My RSUs | SCMS |
| 5. FCC | License each RSU site before transmitting on 5.9 GHz | FCC licensing | |
| 6. Push | Store MAP, TIM and RSM on the RSUs; confirm the generator feeds SPaT; set delivery windows | creator, map builder | TIM, RSM |
| 7. Verify | Decode what the RSU actually sends (from its message store or a sniffer), check the live overlay, run through a signal cycle, drive the approaches | decoder, live view | MAP to SPaT, certification and plugfests |
| 8. Collect | Forward received messages to the portal, record sessions, set triggers | live view | live BSM and breadcrumbs |
| 9. Analyze | Export CSV, GeoJSON and JSONL; compute measures; share the recording ID with reviewers | API | below |
A priority pilot adds the SRM/SSM steps in signal priority; a work-zone pilot adds a WZDx feed into TIM and RSM generation; a perception pilot adds SDSM from a roadside sensor (SDSM).
Datasets and tools worth knowing
| Resource | What it is | Use it for |
|---|---|---|
| USDOT ITS DataHub | Catalog of public connected vehicle datasets, including the Wyoming (I-80 freight and weather), Tampa (THEA, downtown with transit and pedestrians) and New York City pilot data, with BSMs, TIMs, SPaT and event logs | Realistic message volumes and formats; ground truth for decoder tests; before-and-after studies |
| USDOT ITS CodeHub | Index of open-source ITS software | Finding tools below and their peers |
| jpo-ode (Operational Data Environment) | Open-source ingest and decode pipeline for BSM, TIM, SPaT, MAP, SRM, SSM with Kafka output; the JSON shape the portal's API uses is compatible with its records | Back-office pipelines; comparing decodes |
| CARMA Platform and CARMA Streets | Open-source automated driving and roadside cooperative software from FHWA | Automation research that consumes SPaT, MAP, SDSM |
| V2X Hub | Open-source roadside application platform that bridges controllers (NTCIP 1202), RSUs and messages, with SPaT, MAP, TIM, SRM and SDSM plugins | A free SPaT generator and priority request server for a pilot |
| OmniAir | Certification and plugfests for OBUs and RSUs | Interoperability evidence; see certification and plugfests |
| CTI 4501 and CTI 4001 | Connected Intersections and RSU specifications from the ITE/AASHTO/NEMA Connected Transportation Interoperability program | Requirements for procurement and verification |
| SAE J2735, J2945/x, J3224 and IEEE 1609.x | The message, performance and security standards | The standards overview lists current revisions |
| This portal's templates and API | Validated example messages for every type, decode and encode endpoints, exports | Unit tests, teaching, data generation |
Reproducible experiment checklist
- Record the dictionary revision used for every decode (the portal reports it and the exports carry it).
- Keep the raw bytes (JSONL
raw_hex) with every decoded record so anyone can re-decode with another tool. - Keep the MAP and SPaT generator configuration at each site as files under version control, with
revisionnumbers in the file names. - Log RSU firmware versions, radio settings and time source (
rsuFirmwareVersion,rsuClockSource) at the start and end of each collection. - State the retention and privacy rules applied to trails before collection starts.
- Capture control data: the same sites and times without the treatment, or a comparison corridor.
- Define measures before collecting: for SPaT applications, red-light arrivals and stop-line crossings on red; for priority, grants, extension seconds, schedule adherence, side-street delay; for work zones, speed compliance and hard-brake events at the taper.
- Report message rates and losses (the live view's rate chart and the
msg_cntgap counts in exports). - Share the recording IDs and export checksums with your paper or report.
How to cite the portal
ITS Roads, LLC. ITS Roads CV2X Portal: SAE J2735 decoder, creator, MAP builder and live V2X data tools. https://cv2x.itsroads.com, accessed on the date you used it. Cite the dictionary revision (for example SAE J2735_202409) and the recording or export identifiers alongside it. The portal's own decoder and encoder are built from the published ASN.1 and are validated by round-trip tests on every template; if you find a disagreement with another tool, send both decodes and we will investigate and publish the finding.
Teaching with it
Instructors use the decoder with the ? field help as a guided tour of a message, the creator templates as assignments ("make the bus request priority on the correct lane"), the map builder to teach intersection geometry, and the demo feed in the live view to show a signal cycle and a priority grant without any hardware. The wiki articles are written to be assigned as reading; the units cheat sheet is the one to print.
A dedicated managed instance
The public portal is shared and rate-limited, and it must not hold an agency's credentials beyond what its RSU registry needs. For a pilot that wants more, ITS Roads provides a dedicated instance: the same software on infrastructure the agency or university chooses, connected to the agency network by VPN so RSUs forward over private addresses, with higher quotas, longer retention, user accounts for the whole team, scheduled TIM and RSM generation from the agency's feeds, controller connectivity for SPaT and priority, enterprise monitoring of the RSUs and the security subsystem, and support from engineers who have done this on state DOT fleets. Contact ITS Roads with the sites, the fleet and the application, and we will scope it. Research collaborations with universities are welcome, including joint publications on the data.