DETAILED OVERVIEW OF VII
Over the last 20 years, vehicles have become “smart” through the incorporation of numerous electronic sensors and computer processors. However, they remain much like early PC’s—isolated, stand-alone devices that cannot exchange information with one another or with the outside world. Just as the Internet has revolutionized computing at home and in the office, Vehicle Infrastructure Integration (VII) has the potential to revolutionize surface transportation, by allowing vehicles to communicate with one another and the rest of the networked world.
VII is a research program focused on enabling wireless communications among motor vehicles and between motor vehicles and roadside infrastructures. This involves various public and private sector entities. By enabling secure real-time communications with motor vehicles, new services will be enabled to enhance transportation safety, mobility, and commerce.
VII holds the promise of significantly decreasing traffic accidents and fatalities through secure and trusted vehicle-to-vehicle communications. To achieve this goal, vehicles will privately communicate their location, using greater accuracy than today’s advanced GPS Systems, as well as their speed and heading to all nearby vehicles. This information will be used by processors on-board vehicles to assess the likelihood of a collision or other safety hazard and provide drivers with greatly enhanced situational awareness. For example, today vehicles traveling behind larger vehicles have reduced visibility and may not be aware of hazards on the roadway or stopped vehicles ahead. With VII, an electronic brake warning system will notify drivers of such incidents so that they can take appropriate action. The advancements that VII provides will lead to the development of innovative driver warning and/or automatic vehicle control systems, enabling significant enhancements in vehicle safety.
VII is a “system of systems” which includes both vehicle-to-vehicle and vehicle -to- infrastructure communications. When fully implemented, it would provide transportation managers with complete awareness of motor vehicle movements, thus allowing for quick detection of roadway incidents and hazards and the development of real-time traffic control systems that hold the promise for substantially reducing travel delays and increasing the effective capacity on existing roadways.
To achieve the goals of VII, motor vehicles in the United States will need to be equipped with On-Board Equipment (OBE) consisting of one or more communication devices, a positioning device, a processing platform, and application software. For several safety applications, the OBEs will exchange data with Road Side Equipment (RSE), or roadside transceivers. The OBEs will also communicate with other OBEs for vehicle-to-vehicle data exchange. In the VII Proof of Concept research, vehicle-to-vehicle and vehicle-to-infrastructure communication is enabled by using a dedicated 5.9 GHz bandwidth allocated by the Federal Communications Commission (FCC). This is specifically to achieve vehicle safety goals. In order to meet the secure, low latency, high availability
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requirements of VII safety systems, a combination of this dedicated spectrum and appropriate communications standards are needed. These standards are being developed based upon the widely-used IEEE 802.11 (Wi-Fi) standards. Other applications may use the same vehicle to roadside link, or may use other communications media.
Privacy protections have been built into the system to ensure that all vehicles remain anonymous and the routes and locations of individual vehicles cannot be tracked without the driver’s permission. In addition, a Privacy Framework has been developed and vetted by key privacy advocacy groups.
VII INFRASTRUCTURE
In order to achieve this vision, the exchange of information between vehicles and the “infrastructure” must be secure. Message management is necessary to protect motorists’ privacy, ensure driver safety, and control the flow of information in a manner that ensures proper prioritization of messages and utilization of available wireless capacity. For example, safety related messages must take priority over other commercial or convenience messages. In short, a VII communications network must be engineered to properly control, authenticate, and manage messaging between on-road vehicles and other entities wishing to send and receive information with those vehicles.
The VII research program has developed a baseline, VII architecture to address message security needs. The architecture is subject to be modified based on results of testing and other research activities. In addition to the on-board and roadside equipment, additional infrastructure is needed to collect and provide information, manage the network, protect the security of individual messages and to connect the system together. Service Delivery Nodes (SDN) provides the primary network connectivity to RSEs. Messages traversing the VII System are protected using digital signatures and encryption as well as public and private keys issued by a Certificate Authority (CA). This ensures that all entities and users of the VII System can verify that a particular message is from a valid source and can be trusted. The use of leading edge encryption techniques and a separate Certificate Authority also ensures that the privacy of individual motorists is protected and communications are secure. One or more Enterprise Network Operations Centers (ENOC) provides network level control. Various technologies can support the communications needs between the system elements.
VII ENABLED APPLICATIONS AND SERVICES
The VII concept allows for the development and deployment of new applications and services that can enhance safety, mobility, and convenience for motorists. These applications take advantage of the unique security, privacy, performance and real-time nature of the communications built into the VII systems.
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Safety Applications: The primary purpose of VII is the potential to significantly improve safety. Safety applications rely on “heart-beat” messages sent from the OBE, indicating the location, speed and heading of vehicles. The speed at which the VII system can detect, process, and deliver information about hazards is extremely important in safety applications—drivers often have seconds or less to take actions to prevent crashes when traveling at high speeds. VII Safety Applications include:
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Traffic Signal Violation Warning: This application calls for VII equipped traffic signals to broadcast their phase status (i.e., red, green, yellow status) to all VII-equipped vehicles approaching the intersection. Processors within the vehicle can use the signal information, combined with the vehicle speed and location, and the location and speed of other vehicles to warn the driver of a dangerous situation.
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Stop Sign Violation Warning: In this application, an RSE broadcasts the precise location of stop signs to surrounding vehicles. Like the traffic signal violation warning application, processors on the vehicle can use this information, combined with the vehicle speed and location to warn the driver of a potential stop sign violation.
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Driver Assistance at Intersections: The VII system also has the potential to assist drivers with dangerous maneuvers at intersections, such as when making turns onto a busy roadway. The system lets drivers know when there is an adequate “gap” between vehicles traveling on the crossing facility to make a turn or cross the roadway. This type of assistance is particularly beneficial at high speed rural intersections without signals, and for drivers making left turns at signals without a protected left-turn phase.
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Curve Speed Warning: This application would broadcast precise roadway geometry and road condition information such as reductions in pavement friction due to adverse weather conditions to vehicles approaching a curve. The vehicle can then use this information, combined with an awareness of its own speed and location, to warn the driver if he or she is approaching the curve too fast.
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Electronic Brake Warning: This application calls for VII equipped vehicles to immediately broadcast a “hard braking” message whenever the vehicle’s deceleration rate exceeded a preset limit. Other vehicles in the vicinity receive this anonymous message and, if appropriate, warn the driver that a vehicle ahead is stopped or is decelerating quickly. This application will help prevent vehicle pile-ups that sometimes occur when a vehicle in fast-moving traffic suddenly makes a panic stop.
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In-Vehicle Signage: This application is focused on broadcasting various warnings and signage information to motorists at the appropriate times and locations. A VII equipped vehicle can use this information, combined with an awareness of its own location, speed and heading, to display messages to the driver. Examples of in-vehicle signage include: work zone warnings, speed limit warnings, vehicle size or
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weight warnings, one-way street or “no entrance” warnings, and numerous other infrastructure signage.
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Adverse Weather & Pavement Condition Warning: This application alerts drivers to local safety hazards such as changes in pavement condition or deterioration in driver –level weather. VII equipped vehicles will provide data that will allow for the inference of local weather and pavement conditions. This data can be transmitted to roadside equipment where it can be processed and ultimately turned into a warning message sent to upstream vehicles that are approaching the hazard. Examples of Adverse Weather and Pavement Condition Warnings include (but are not limited to) significant changes to tire fiction (e.g. slipperiness) on the road surfaces due to the presence of ice, snow or standing water, the occurrence, intensity and type (liquid or frozen) of precipitation and visibility hazards due to dense fog, dust or smoke.
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Commercial Vehicle applications: This application seeks to provide a framework for improving commercial vehicle safety, operational efficiency, security and freight mobility. This is done through the application of interoperable technology and information sharing in the vehicle, on the road, and in off-road systems. It will address the most important factors affecting commercial vehicle safety, security, and mobility, avoid duplication of effort. It will target resources/funding at countermeasures (technological or process-oriented) that are most likely to deliver operational benefits to public- and private sector stakeholders. As a result, commercial vehicles, motor carriers, enforcement resources, highway facilities, intermodal facilities, toll facilities and other nodes on the transportation system can collect data for their own purposes and share the data seamlessly.
Mobility Applications: Core to the VII concept is the notion that vehicles will act as anonymous probes as they move along roadways. The vehicles will continuously transmit “probe data” that is collected and utilized by transportation managers and private entities to enhance the mobility and safety of drivers. The standard that defines the probe data set, Society of Automotive Engineers (SAE) J2735, has been designed to ensure that all probe data transmitted from a vehicle is absent of any identifying information that could be used to link it to either the driver or a specific vehicle. Probe data will include the location, speed, and heading of the vehicle. As well as: outside air temperature, headlight status, wheel slip events (ABS system activation which would indicate slippery conditions), windshield wiper status, and data from other on-board sensors which measure environmental and road surface conditions. All of this data is both time and location “stamped” as vehicles move along the roadway network.
Probe data provides the essential information needed by transportation managers to detect traffic congestion, incidents, adverse weather and road conditions and other hazards. Transportation agencies can use this information to clear hazards faster, adjust traffic control devices (such as traffic lights, ramp meters, and lane control devices), and to provide detailed advisory messages to motorists, thereby reducing traffic delays and improving flow. When built out, the VII system has the potential for providing data with
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substantially better quality, coverage, and timeliness of delivery for traffic management applications than existing sources. Mobility applications made possible by VII include:
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Traffic Signal Optimization: This application optimizes the control of traffic signals along a particular roadway or within a particular roadway network. This is in response to real-time traffic data being collected from VII-equipped vehicles and delivered to transportation management centers.
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Ramp Metering: Similar to traffic signal optimization in concept, this application optimizes the timing of ramp meters to ensure smooth, safe, and efficient flow of vehicles onto expressways from entrance ramps.
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Traveler Information: This application assesses roadway condition, incident, and congestion information based on the collected probe data. It then develops highly accurate and timely advisory messages that can be delivered to the appropriate locations within the roadway network. Then motorists can act on the information to alter their travel route, speed, or even the time they choose to travel.
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Corridor Management: This application utilizes the probe data collected by the VII network to determine if delays are being caused by too many vehicles on a specific roadway. It then leverages the previously described applications (traveler advisories, signal control, ramp control, as well as other traffic control devices) to shift traffic flow patterns and better balance flow through the corridor.
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Roadway Maintenance: Data from the VII system can enable State and local road maintenance organizations to better determine the timing, location and nature of needed roadway maintenance. This is based on information such as vehicle-based outside air temperature, windshield wiper status and pavement friction sensors such as Anti-lock Braking System (ABS) or Vehicle Traction Control (VTC) activation. Improved maintenance activities will include more precise usage of snow removal equipment, personnel and anti-icing and deicing chemicals which will save money and will reduce environmental impacts as well provide information on locations for pothole repairs.
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Commercial Vehicle Operations: Data obtained from both commercial and passenger vehicles will provide a complete picture of traffic conditions on the national highway system as well as indicate potential problem areas due to weather (e.g., corridor with high winds, passes that require chains). VII data will be available 24/7 from both urban and rural corridors which will make the planning and execution of long haul trucking operations safer and more efficient. VII also has potential for significantly enhancing transit and operations. Potential applications are beginning to be explored.
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Convenience and Commercial Applications: While the focus and priority of VII are to support applications that will enhance safety and mobility, the communications infrastructure and on-board technologies can also be leveraged to enable various
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applications that improve convenience and support commercial services. Examples of such applications include:
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Electronic Toll Collection: The VII concept can readily support a variety of existing and future electronic tolling concepts that can help reduce the need for traditional toll plazas. This will also allow for increased flexibility in establishing the basis on which tolls are collected. For example, the amount of a toll could be tailored to take into account vehicle size, type, and emissions rating, as well as the number of passengers in the vehicle, time of day and other factors. The electronic toll tag is effectively built into the VII on-board equipment and can be set up by the driver (or owner of the vehicle) to utilize multiple accounts for paying the toll—this increases convenience and flexibility for the motorist.
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Other Electronic Payment Services: The VII concept will also allow for secure and convenient wireless payment of various services directly from electronic accounts that can be maintained and managed on-board the vehicle. For example, parking garage fees, fast-food drive through charges, or even gasoline charges could all be paid for wirelessly and automatically from electronic accounts authorized by the driver or vehicle owner.
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Remote Diagnostics and Warranty Management: The VII communications network could be leveraged by vehicle manufacturers to conveniently and comprehensively collect diagnostic information from vehicles. By doing so, vehicle manufacturers could be alerted much faster of developing problems with safety related systems and/or with other performance and functional product issues. Corrective actions could be put in place early to help prevent small problems from becoming large—thus enhancing safety while improving reliability for the motorist.
The VII system offers a flexible, robust, efficient and secure means of communicating directly with motor vehicles. The VII system therefore provides the platform upon which numerous new services can be developed. This will enhance the safety, mobility, and convenience of travel. The applications described above represent only a small handful of the potential made possible by VII.
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