When should ADS Fallback? A Critique of the Solution for Improving the SAE Conditional Driving Automation Definition

When should ADS Fallback? A Critique of the Solution for Improving the SAE Conditional Driving Automation Definition | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article When should ADS Fallback? A Critique of the Solution for Improving the SAE Conditional Driving Automation Definition Yaowei Liang, Suzan Ayas, Greg A. Jamieson This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7687979/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The Society of Automotive Engineers International standard J3016 defines five levels of driving automation. Among these, Inagaki and Sheridan ( 2019 ) used mathematical derivations to argue that the definition of SAE level 3 is incomplete and proposed an additional level between it and SAE level 4. In their proposed level, if the driver fails to respond to a request to intervene within several seconds, the automated driving system performs a dynamic driving task fallback. However, their derivation may overlook the fact that waiting for driver intervention increases risk as the vehicle continues approaching the operational design domain boundary. We extend Inagaki and Sheridan’s ( 2019 ) framework by modeling the available intervention time as a continuous, time-dependent variable to rederive the expected utility, while considering the increasing risk of longer available intervention time. Our results show that, for an automated driving system with a fallback function, executing fallback immediately rather than waiting for driver input increases expected utility. These findings challenge Inagaki and Sheridan’s ( 2019 ) proposed solution for improving the J3016 taxonomy and weaken the necessity of adding a level between SAE level 3 and SAE level 4. Automated driving Levels of driving automation Takeover time SAE J3016 Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7687979","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":528343311,"identity":"8b0a32e3-ac07-40cb-973a-2004f066f010","order_by":0,"name":"Yaowei Liang","email":"","orcid":"","institution":"University of Toronto","correspondingAuthor":false,"prefix":"","firstName":"Yaowei","middleName":"","lastName":"Liang","suffix":""},{"id":528343312,"identity":"dbca997c-91db-4a9d-890d-1415af1c7c15","order_by":1,"name":"Suzan Ayas","email":"","orcid":"","institution":"University of Toronto","correspondingAuthor":false,"prefix":"","firstName":"Suzan","middleName":"","lastName":"Ayas","suffix":""},{"id":528343313,"identity":"7cde8162-4de5-4150-a0a1-e4112dae0f1a","order_by":2,"name":"Greg A. 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A Critique of the Solution for Improving the SAE Conditional Driving Automation Definition","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Automated driving, Levels of driving automation, Takeover time, SAE J3016 ","lastPublishedDoi":"10.21203/rs.3.rs-7687979/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7687979/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe Society of Automotive Engineers International standard J3016 defines five levels of driving automation. Among these, Inagaki and Sheridan (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) used mathematical derivations to argue that the definition of SAE level 3 is incomplete and proposed an additional level between it and SAE level 4. In their proposed level, if the driver fails to respond to a request to intervene within several seconds, the automated driving system performs a dynamic driving task fallback. However, their derivation may overlook the fact that waiting for driver intervention increases risk as the vehicle continues approaching the operational design domain boundary. We extend Inagaki and Sheridan\u0026rsquo;s (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) framework by modeling the available intervention time as a continuous, time-dependent variable to rederive the expected utility, while considering the increasing risk of longer available intervention time. 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