Building a compliant and interoperable blockchain architecture for U.S. connected and automated vehicles

<p dir="ltr">Connected and automated vehicles (CAVs) are coming to fruition and promise to deliver many benefits. Modern cars have some automated functions, typically Level 1 or Level 2 on the Society of Automotive Engineers’ levels of autonomy. As original equipment manufacturers (OEMs) develop vehicles with higher-level functionality (e.g., Level 3 or Level 4 capabilities), legislators and researchers are trying to solve legal and technical challenges with CAVs. On the technical side, researchers explored blockchain as a possible solution to some of the technical difficulties CAVs face. For example, several studies created blockchain frameworks and architectures to support liability and adjudication, vehicle registration, and vehicle maintenance. However, one significant gap in the existing literature is that none of the frameworks, architectures, or functionalities set out to comply with U.S. federal and state legislation.</p><p dir="ltr">On the legislation side, the U.S. federal government asserted that it is responsible for only a handful of items—specifically recalls, certification, and enforcement of the <i>Federal Motor Vehicle Safety Standards</i>. In contrast, states must tackle the remaining legislation topics on their own. Due to the U.S. federal government’s position of letting states drive legislation, state CAV legislation is inconsistent across all 50 states. Due to the inconsistency, technical researchers and OEMs face significant challenges in standardizing solutions and deploying CAVs.</p><p dir="ltr">The study’s research question is: What blockchain architecture for U.S.-based connected and automated vehicles complies with federal and state legislation and is interoperable across all 50 states? The purpose of this study was to develop and implement a blockchain-based architecture for U.S. CAVs that is compliant with U.S. federal and state legislation and interoperable across all 50 states. To build the architecture, the study derived the minimum compliance requirements required for each legislative topic (e.g., CAV registration) by using the textualism theory for statutory interpretation. The researcher combined the technical requirements, defined in Chapter 3, and the derived compliance requirements to form a comprehensive set of requirements for the blockchain architecture. The compliance requirements were sent to two experts to evaluate if the requirements were the minimum compliance requirements and if they enabled interoperability between states. One expert confirmed that the documented requirements are the minimum statutory compliance requirements and that they would help enable interoperability. With the requirements in place, the researcher created architecture diagrams to document the functionality and architecture of the blockchain system. Next, the researcher built a proof-of-concept that implemented the blockchain architecture (including the chaincode). The researcher performed interoperability tests by executing chaincode for states with similar and dissimilar requirements. After the interoperability tests were performed, the researcher ran performance tests for each use case. The implementation was able to sustain a throughput four times higher than the expected average load (note that the researcher only tested up to loads four times the expected amount).</p><p dir="ltr">The study’s final deliverables included a collection of architectural diagrams, two experts’ evaluation of the minimum compliance requirements, JSON schemas for each use case, the performance test results of the proof-of-concept, and a working implementation of the blockchain architecture.</p><p dir="ltr">Note that one of the goals of the architecture presented in this study was to facilitate interoperability. The architecture and implementation supported interoperability without requiring states to adopt the same approach or legislation.</p>