目前，业界到底将采用基于蜂窝网络的CV2X 还是采用无线 DSRC（专用短距离通信）技术仍尚无定论，FCC 宣布将收回频段的问题也尚无解决方法。但从技术层面而言，保护弱势道路用户安全的解决方案已经成熟。
长期以来，供应商以及汽车和摩托车OEM一直在进行高效自动交通警报系统方面的合作。2019年 CES 消费电子展上，大众汽车集团（VW Group）旗下奥迪（Audi）、福特（Ford）和杜卡迪（Ducati）品牌展示了他们与高通（Qualcomm）共同开发的V2X 技术。展览期间，他们借助一辆杜卡迪 Multistrada1260 汽车，展示了基于蜂窝网络的 V2X 技术在非视距传播（NLOS）场景下的应用。高通也是5G 汽车协会（5GAA）的成员，其他参与公司还包括宝马（BMW）、福特和 PSA 集团。2018 年，5G 汽车协会开始展示乘用车、摩托车与道路基础设施之间的基于蜂窝网络的V2X 通信。与宝马很类似，本田（Honda）也同时生产汽车和摩托车。目前，这家公司正在与全球最大的两家摩托车联盟合作，包括欧洲的网联摩托车联盟（Connected Motorcycle Consortium，CMC）和美国的安全摩托车运动研究联盟（Safer Motorcycling Research Consortium，SMRC）。这两家联盟的成员几乎涵盖全球所有大型摩托车OEM。
“幸运的是，我们可以为我们的摩托车和汽车部门提供密切合作的机会，这两个部门每周都会交换一些技术和法规相关的信息。”本田北美研发汽车技术研究部门总工程师Sue Bai 解释道，“CMC 是在 2015 年 ITS 世界大会期间成立的，但我个人从早在 10 年前就一直与 CMC 本田团队开始合作了。”
与其他任何新技术一样，成本总是限制技术应用推广的关键，摩托车行业尤是如此。举个例子，ABS技术早在 10 年就已经上市，但直到现在才刚刚登陆一些入门型摩托车，主要也仅面对新手中的新手客户。
“与汽车应用相比，摩托车通常更在乎成本，并且由于空间较小，天线等硬件设备的安装也更有挑战。”Bai指出，“摩托车骑手的身体很容易阻挡信号，导致难以实现 360 度传输。对此，我们的建议是采用一前一后共两个天线。这种设计确实会增加成本，但为了保证安全，这可能将成为一种必须。”
摩托车还要求所有部件都防水。目前，本田已经在俄亥俄州的智能交通走廊33 号公路部署了 2 辆摩托车，用以收集有关车辆组件密封性和稳健性的数据。
博世公司在摩托车安全领域一直是主要供应商和创新者。这家公司从十几年前就开始进行网联项目了。在美国密歇根普利茅斯市，博世公司北美V2X 和网联产品汽车多媒体团队产品经理 Suman Yelati 说，“博世在 V2X 领域投入了大量人力与物力。”他表示，自 2008 年以来，博世公司一直在进行“标准化前”阶段的工作，“积极与一些委员会合作参与标准的制定，并且与其他OEM开展了大量合作项目。”
根据Yelati 的说法，V2X 技术可以提供车辆雷达和摄像头看不到的数据，为车辆提供更全面的信息，从而协助车辆更好地进行决策，这将成为自动驾驶生态系统的有力补充。他说，“举个例子，V2X可以协助车辆看到一些‘视线范围之外’的车流。尽管雷达、激光雷达和摄像头都具备分析视觉输入的能力，但只有 V2X 技术才能获取视线范围之外的信息。此外，与摄像头相比，V2X的延迟也更低。假设我前方第 10 辆车进行了紧急制动 [事件]，那么直接通过 V2X 技术将该信息传递给我要比等着摄像头来处理这些信息来得更快。”
目前，V2X 技术的相关标准（包括 SAE J2735 https://www.sae.org/standards/content/j2735_201603/）已经就位、相关解决方案已成型，各大主要供应商和OEM也做好了部署的准备，但对于美国等全球主要市场，现在 V2X 技术面临的主要挑战还是在监管环境和基础设施方面。最终，无论美国最终到底选择部署DSRC 或 CV2X，业界似乎都已经做好了两手准备。
“作为一家一级供应商，我们是技术中立的。”博世公司的Yelati 表示，“因此，无论是 DSRC 还是 CV2X，我们都有相应的产品给OEM。”
本田公司的 Bai 指出，FCC 美国联邦通信委员会在 2019 年曾宣布可能收回之前为 V2X 技术留出的频谱，该问题比到底要选 CV2X 还是DSRC 更为紧迫。“只要V2X 技术的稳定性和健壮性都验证没问题，我们就不用纠结要选哪个了。”Bai 表示，“我认为，现在当务之急是把 5.9 GHz 频段争取下来，而不是在两种技术之间PK。”
Bai 表示，没有频谱，就没有传输通道，那就更不用谈V2X 的发展。她说，“这些标准都已完成发布，立马就可以使用，而且已经有一些试点项目已经开始采用这些标准了，这并不仅仅关乎摩托车。”
具体来说，FCC曾在 2019 年建议把分配给 V2X 通信的频谱范围从 75 MHz 减少到 30 MHz，这无疑将减少 V2X 系统可以提供的功能数量，并同时降低系统的有效性和容量。Yelati表示：“许多应用程序非常复杂，需要多个通信通道，只给 30 MHz 带宽根本无法实现。如果 FCC 真要减少带宽，那就相当于直接给此类应用程序判了死刑。”
Bai 指出，此项规定将对V2X 技术的部署产生决定性不利影响。“如果 FCC 将大部分频谱分配给其他技术，那么在考虑到左右通道 Wi-Fi 干扰的情况下，其实 V2X 技术真正可以使用的安全通道数量不超过2 个。”Bai 提到了丰田信息技术实验室主任（Toyota InfoTech Labs）John Kenney 曾在 2020 年 SAE 政府/行业会议上打的一个比方——这就相当于要把召开摇滚音乐会的场地放在医院两边。
除了上文介绍的基础设施和带宽问题，下一个需要面对的挑战在于安装，这通常需要较长时间。摩托车等车辆的V2X 功能可能会分阶段推进，先从简单的信标功能到人机界面（HMI）警报，再到更高级的主动应对策略（这就像是也为摩托车配备了 ADAS 技术）。事实上，让更多的弱势道路用户加入V2X 网络，特别是在交叉路口等繁忙位置，才能让 V2X 技术发挥最大效用。
大陆集团（Continental）正致力于提升危险交叉路口安全性。这家公司主要通过创建虚拟用户的方式，将位于某一交叉路口的全部道路用户“数字化”。“如果V2X 技术的普及率不高，那系统将很难发挥全部作用。在此背景下，我们认为通过为所有十字路口增加安全传感器，用以收集所有道路用户的信息，包括行人、自行车、摩托车、汽车和卡车等，并将这些信息广播出去可以让系统发挥最大潜力。”大陆集团被动安全和传感器部门的业务发展经理Kent Young 解释说，“之后，我们就可以代表所有道路用户，发送基本安全信息，无论这些道路用户自身是否具有 V2X 通信功能。”
根据 NHTSA-美国高速公路安全管理局的数据，大陆集团将在美国摩托车事故多发的交叉路口（占2017 年全美摩托车致死事故的 35%）部署 V2X 基础设施，并创建虚拟的 V2X 行人。
Young 表示，“只要能在基础设施中部署V2X 技术，我们就可以实现让每一辆汽车和每一个位弱势道路用户（行人、自行车、摩托车等）都能发送 V2X 信息，从效果上相当于达到 100% 的 V2X 通信功能普及率。”他指出，日后，当自动驾驶汽车真正成为现实后，也能从交叉路口的V2X 基础设施中获益，提高运行性能。
Young 表示，“我们将在交叉路口广播V2X 消息，任何配备 V2X 设备的车辆都可以接收这些信息。”除了安全优势外，V2X 技术还可以用于调整信号时序，充分考虑交叉路口的行人情况。“我们并不识别用户，因此不牵扯任何保密事宜，但正在通过提高技术的有效性来提高安全性。”
Young 在谈到他们与原厂客户的合作进展时表示，“大陆集团深耕V2X 技术多年，那时全球仍仅有美国和欧洲等少数发达地区在进行相关研究。如今，我们正在与多家原厂客户积极进行 V2X 开发。”大陆集团会将公司在 V2X、雷达和摄像头等量产产品中的‘精华’应用在基础设施项目中。Young表示，目前，我们有三处交叉路口测试现场已投入使用。他预计这项技术将在未来五年内投入使用，届时公司将直接与市政当局合作。
对于摩托车等弱势道路用户，V2X的确可以带来大量安全优势，但数据隐私和所有权问题也同样棘手。美国摩托车手协会（American Motorcyclist Association，AMA）最近上任的政府关系主任Michael Sayre 表示：“摩托车手并不是唯一想得到这些车辆数据的人。事实上，车主和制造商均需要参与开发过程，以确保我们的数据受到保护，无论这些数据来自我们自己的联网摩托车还是来自周围的联网汽车。”
“等到这项技术达到近乎完美的水平时，我们可能就再也不用听到‘对不起，我真的没有看到那边有一辆摩托车’这样的自责话语，这将是一个巨大的进步，”Sayre说，“但通常来说，涉及多辆摩托车的摩托车事故仅占事故总量的一半，其余的是单车事故，而且原因多种多样。不过，其中一些问题可以通过 ABS 防抱死制动器和稳定控制等技术得到解决。”
Sayre 指出，潜在问题之一在于公众是否会过度依赖该技术。这个话题并不陌生，汽车领域的ADAS 也一直面临同样的问题。他说：“如果汽车驾驶员由于过于依赖车辆的联网功能，而误以为绝大多数车辆都是联网的，但事实上仅有少数车辆联网，而主观上直接忽视自己明明已经看到的摩托车，这就会造成严重后果。”
“我们从NHTSA 得到了非常积极的回应，他们近期公开表示正在认真考虑 ‘NCAP-ing’ V2X 技术的可能性，这将是我们的巨大胜利。”Bai 表示，“目前，本田已经不存在技术方面的阻碍，我想很多其他主要OEM的情况也一样。”
For motorcyclists and other vulnerable road users, V2X communication is a vital safety asset for the AV future.
As development of autonomous vehicles (AV) moves inexorably forward, connectivity—also known as vehicle-to-everything (V2X) communication—will play a crucial role in their adoption. Much of the necessary V2X technology is already available, leaving regulatory and infrastructure challenges as the remaining major obstacles to an effective network rollout.
Deployment of V2X capabilities could be a boon to vulnerable road users (VRUs) such as motorcyclists, cyclists and pedestrians, according to safety experts. It is connectivity, not autonomy, that will alert a vehicle that traffic ahead has stopped, or that a motorcycle hidden behind buildings is approaching an intersection. ADAS and AV sensor suites help vehicles that are so equipped navigate their immediate environments in real-time, but it is the V2X network that promises to bring a safer, omniscient view of the road ahead to the VRUs as well.
Communication standards – cellular-based CV2X vs. DSRC (dedicated short-range communications) wireless – and public-spectrum bandwidth issues have yet to be sorted. But in terms of the tech, solutions for providing greater on-road protection to VRUs exist today.
Suppliers, along with automotive and motorcycle OEMs, have been collaborating on what is effectively an automated traffic-alert system. VW Group’s Audi, Ford and Ducati showed off their joint-development efforts in V2X technology with Qualcomm at CES 2019. They used cellular-based technology to demonstrate a cooperative intersection use case in a non-line-of-sight (NLOS) scenario involving a Ducati Multistrada 1260. Qualcomm also is part of the 5G Automotive Association (5GAA) whose members include BMW, Ford and the PSA Group. In 2018, 5GAA began demonstrating direct cellular V2X communication between passenger vehicles, motorcycles and roadside infrastructure. Honda, like BMW a manufacturer of both cars and motorcycles, is working with the Europe-focused Connected Motorcycle Consortium (CMC), and its U.S. equivalent, the Safer Motorcycling Research Consortium (SMRC). Both groups now count nearly every major motorcycle OEM as members.
“We are very fortunate that the motorcycle team and the car divisions are working very closely. We exchange information on a weekly basis on both technical and regulatory issues,” explained Sue Bai, chief engineer in the Automobile Technology Research division of Honda R&D Americas. “The CMC was established in 2015 during the ITS World Congress, but I have been working with the CMC Honda team for more than 10 years.”
Like any new technology, cost is key to proliferation—and it’s a particularly acute issue for two-wheelers. An example is ABS, which after decades in the market is only now making its way onto entrylevel bikes that often are purchased by the most inexperienced riders.
“The motorcycle is more cost-conscious compared to a vehicle implementation, and it has smaller spacing for equipping antenna and hardware on it,” Bai noted. “The rider’s body blocks some of the signals to achieve 360-degree transmission. Our recommendation is to have two antennas, one in front, one at the back. It does have implications to the cost, but to ensure the safest implementation, that may be needed.”
Motorcycles also require all components be waterproofed. Honda currently is deploying two motorcycles in the Ohio Route 33 Smart Mobility Corridor program to collect data and vet component sealing and robustness.
Bosch, a major industry supplier and innovator in the motorcycle safety space, also has spent more than a decade on connectivity projects. “Bosch is heavily invested in the V2X area,” said Suman Yelati, the company’s Plymouth, Michigan-based manager of the car multimedia team in North America for V2X and connectivity product. He said that since 2008 the company has been working in pre-standardization areas, “and also in standardization and various committees related to V2X public-funded projects and collaborator projects with OEMs.”
According to Yelati, V2X is complimentary to the autonomous ecosystem, providing additional data to radar- and camera-based inputs to improve overall decision making. “For example,” he said, “V2X can help see non-visible traffic. While radar, lidar and cameras are all able to analyze visual input, V2X messages go to non-line-of-sight areas. The latency is also less compared to camera processing, so if there’s an emergency braking [event] 10 vehicles ahead of me, that gets communicated to me faster via V2X message than a camera processing all this information.”
Roadblocks to connectivity
With standards including SAE J2735 [https://www. sae.org/standards/content/j2735_201603/] in place, technological solutions available and key suppliers and OEMs ready to deploy, the remaining barriers in the U.S. and other markets are more centered on regulation and infrastructure. Whether the system ultimately deployed in the U.S. is based on the DSRC or CV2X, industry appears ready to support either protocol.
“As a Tier 1, we are technology-neutral,” Bosch’s Yelati said. “So whether DSRC or CV2X, we are ready with the systems to provide the OEMs, whichever it is.”
Honda’s Bai noted that the FCC’s announcement in 2019 that it might take back spectrum previously set aside for V2X is the more pressing issue than CV2X vs. DSRC. “As long as it’s validated, stable and robust, let’s move on,” Bai said. “I think it’s more important to save the [5.9-GHz] spectrum first and spend less time on debating which technology is better.”
Without a spectrum to transmit, there is no V2X future, Bai asserted. “The standards are all set, published and ready to be used, and there are pilot deployments that are using these standards already— and that’s not just motorcycle,” she said.
The FCC’s proposed reduction in allocated V2X spectrum, from 75 Mhz to 30 Mhz, could reduce the number of features available via the system, while also reducing effectiveness and capacity. “A lot of applications will not be possible to be implemented in that 30-MHz bandwidth,” Yelati said, “because complex applications, which involve multiple channels of communication, are completely effected by this reduction.”
The result of such rulemaking would have a detrimental impact to the V2X technology deployment, Bai noted. “If the FCC allocates most of a large portion of the spectrum to someone else, then all the V2X safety communication would be jamming into no more than two usable channels, considering the Wi-Fi interference from the left and right.” She referred to an analogy that Toyota’s John Kenney, director of Toyota InfoTech Labs, made at the 2020 SAE Government/Industry conference, that this would be tantamount to sanctioning rock concerts on both sides of a hospital zone.
Engaging the infrastructure
Once infrastructure and bandwidth are settled, there remains the issue of the installation base, the deployment of which will take time. V2X functionality for vehicles such as motorcycles is likely to progress in stages, from simple beacons to HMI alerts, to more active countermeasures as ADAS tech becomes available for two-wheeler platforms. Getting more VRUs into the V2X network, particularly around intersections, will be key to its effectiveness.
Continental is working to make the most dangerous portion of road networks safer by virtually integrating all intersection users into the V2X network. “If the penetration rate is low, the effectiveness of the system is somewhat limited. So we feel that there’s a real potential to add safe sensors into an intersection, where those sensors can view all road participants in the intersection, including pedestrians, bicyclists, motorcyclists, automobiles, trucks, etc.,” explained Kent Young, business development manager at Continental for the passive safety and sensorics unit. “Then we would be able to send out basic safety messages on behalf of all the road users, whether they have V2X or not.”
Continental’s system would create virtual V2X participants at intersections—a perennial site for motorcycle crashes and where 35% of U.S. motorcycle fatalities occurred in 2017, according to NHTSA.
“With the technology that we can implement in the infrastructure, we can effectively make it as if every single vehicle, every single road user, pedestrian, VRU, motorcycle, bicyclist, in effect would be sending out V2X messages as if it was a 100% penetration rate,” Young said. It will also improve the performance of AVs operating near the intersection – when AVs do enter the market, he noted.
“We would send out these V2X messages and any vehicle equipped with V2X would get this wealth of information about what’s going on in the intersection,” Young said. Additional non-V2X safety benefits include adjusting signal timing to account for pedestrians in the intersection. “We’re not recognizing people themselves, so there’s no confidentiality thing here, but we’re increasing the safety by improving the effectiveness of the technology.”
“Continental has been working on V2X for many years, back when it was just in the research phases both in North America and in Europe, and we are in active development with several customers regarding V2X,” Young said of their progress with OEM clients. The supplier is taking its same high-volume capabilities in V2X, radars and cameras, and implementing those on the infrastructure program. With three test-site intersections already operating, Young said he expected this technology to be in use within the next five years, working directly with cities and municipalities.
Privacy and tech over-reliance
For VRUs such as motorcyclists, V2X could have profound safety benefits. But data privacy and ownership is a thorny issue amongst the notoriously independent demographic. “Motorcyclists aren’t alone in wanting control over the data our vehicles produce with connected vehicle technology,” said Michael Sayre, the American Motorcyclist Association’s (AMA) recently appointed director of government relations. “Motorcyclists and motorcycle manufacturers will need to be engaged in the development to ensure that our data is protected, whether that is data generated by our own connected motorcycle or that which is generated by connected vehicles around us.”
“If this technology was nearly perfect, we could potentially say goodbye to the ‘Sorry I didn’t see the motorcyclist’ type of crash, which would be a huge improvement,” Sayre said. “But multi-vehicle motorcycle crashes typically represent only half of motorcycle crashes. The rest are single-vehicle crashes and have a wide range of causes, some of which can be addressed by technology such as antilock brakes and stability control.”
One potential downside, Sayre noted, is the driving public becoming over-reliant on the technology, which has been a concern with current automotive ADAS technology. “The scenario in which a majority of traffic is connected, while only a small number of motorcycles are, could lead motorcyclists to become even less visible to drivers who are over-reliant on their vehicles to warn them about other vehicles on the road,” he said.
According to Bai at Honda, the most crucial focus currently is to settle the regulatory landscape and begin deploying the technology to start saving lives.
“I got a very positive response from NHTSA, and they recently said in public that they are seriously considering ‘NCAP-ing’ the V2X technology, which is a major step forward,” she said. “Other major OEMs, I think a lot of them are similar in Honda’s position, of technically, we’re ready.”
SAE Autonomous Vehicle Engineering