Transportation safety takes a step forward with C-V2X application standards

Recently released traffic crash data from the National Highway Traffic Safety Administration (NHTSA) revealed that 2020 saw the highest traffic fatality rates since 2002, with 38,824 lives lost in traffic crashes nationwide.¹ Many of these deaths are preventable. Cellular-vehicle-to-everything (C-V2X), a wireless technology that allows vehicles to communicate directly with each other (V2V), roadside infrastructure (V2I/I2V) and potentially pedestrians (V2P), supports information sharing to facilitate safety applications that enhance safety for virtually all road users.

The following use cases illustrate the immediate impact of safety applications that use C-V2X technology:

• Red-light violation warning (RLVW)
  More than half of all fatal and injury crashes happen at intersections. ² The most common cause of all urban crashes – drivers running red lights – result in an average of seven fatalities and more than 1,000 injuries per day at signalized intersections across the country.³

• Intersection movement assist (IMA)
  Similar to RLVWs, IMA safety applications can alert drivers when someone is running a red-light, allowing them to take action and stop before entering the intersection.
• Emergency vehicle pre-emption
  From 2011-2015 alone, roadway incidents accounted for 52 fatal injuries of fire and rescue service responders.⁴ Emergency vehicle pre-emption applications turn traffic signals to green and alert surrounding vehicles to move out of the way, hastening response times and making intersections safer for everyone.

SAE J3161: new C-V2X standards for applications

Every automotive safety scenario has a lot of moving parts within each auto manufacturer, and there are many automotive manufacturers. Hence, standards are the key to ensuring that all those parts interoperate at well-defined performance levels. SAE International has just published a series of fundamental standards designed to promote interoperability and minimum performance among C-V2X devices. The standards will help smooth the way for the transportation stakeholder community to adopt C-V2X and create safety applications that can help to prevent crashes and fatalities. Following is a brief overview of the standards:

• SAE J3161 C-V2X Deployment Profiles — This is a reference system architecture based on C-V2X. The standard is meant for application developers and those interested in CV2X system architecture. This standard defines how to prioritize and deliver different messages between vehicles (V2V) and between vehicles and roadside infrastructure (I2V/V2I) with one 20 MHz C-V2X radio channel at 5.9 GHz.
• SAE J3161/1 On-Board System Requirements for LTE V2X V2V Safety Communications — This addresses the exchange of Basic Safety Messages (BSM) among V2V applications. The standard aims to provide the minimum radio performance, interoperability and data integrity needed for the parts to communicate with one another. 
• SAE J3161/1A Vehicle-Level Validation Test Procedures for LTE-V2X V2V Safety Communications — This provides guidelines for verifying that an Instrument Under Test satisfies the vehicle-level requirements of J3161/1. The OmniAir Consortium will use this standard as the basis for certification testing, verifying device conformance and interoperability. 

While the physical layer third generation partnership project (3GPP) global specifications for C-V2X have been available for some time, the latest “upper layer” SAE  standards are designed to help vehicle manufacturers, Tier 1 suppliers and software stack providers develop consistent safety systems and applications that are interoperable across devices. The same standards will apply to any onboard unit (OBU) for a car or any roadside unit (RSU).

The potential role of C-V2X in road safety

What you can’t see can hurt you, and C-V2X plays a role in safety because it allows your car to see more than you can.  Regular sensors keep vehicles safe in immediate surroundings; C-V2X provides more robust signaling to help vehicles see around blind corners and many other types of obstructions. It connects vehicles and roadside infrastructure that are not in each other’s line of sight and allows them to share information about traffic conditions.

In the use cases discussed above, the sensors and services supported by C-V2X are designed to inform drivers and avert crashes and injuries. For example, with signal phase and timing information and an intersection map, the safety applications can assess a vehicle’s location and speed and estimate whether it will run a red light.

NHTSA believes that safety applications supported by V2V and V2I could eliminate or mitigate the severity of up to 80 percent of non-impaired crashes. That includes crashes at intersections or while changing lanes.

So, the cellular technology is ready, the manufacturers are ready and everybody who wants safer driving is ready. What’s next?

Next steps

Most advances in automotive engineering aim for greater safety, whether for drivers, passengers, or other road users. Now that reliable, timely radio technology is available and widespread, automotive manufacturers can bring the next wave of safe, interoperable products and services to market.

Are you ready to build and deploy automotive technologies based on the new standards from SAE International? Qualcomm Technologies is ready. C-V2X is an integral technology within the Snapdragon Digital Chassis, our set of cloud-connected automotive platforms for telematics and connectivity, computing, and driver assistance and autonomy.

Source citations:

1. NHTSA: Overview of Motor Vehicle Crashes in 2020
2. https://safety.fhwa.dot.gov/intersection/signal/fhwasa11016.pdf
3. https://highways.dot.gov/research/research-programs/safety/intersection-safety
4. https://www.bls.gov/iif/oshwc/cfoi/er_fact_sheet.htm

Snapdragon Digital Chassis is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.