{"abstract":"In this document, NHTSA proposes to amend the Federal motor vehicle safety standard on hydraulic and electric brake systems to include an option for the use of a roll bar structure during specified testing of brake systems in single unit trucks and buses. This option is already available during similar testing of air braked trucks and buses. We tentatively conclude that permitting the use of a roll bar structure would help protect drivers and technicians in the event of a rollover during testing of hydraulically-braked trucks and buses. The safety of drivers and technicians is a primary concern during vehicle testing. The use of a roll bar structure would offer protection to the drivers and technicians performing brake tests conducted at lightly loaded vehicle weight.","action":"Notice of proposed rulemaking (NPRM).","agencies":[{"raw_name":"DEPARTMENT OF TRANSPORTATION","name":"Transportation Department","id":492,"url":"https://www.federalregister.gov/agencies/transportation-department","json_url":"https://www.federalregister.gov/api/v1/agencies/492","parent_id":null,"slug":"transportation-department"},{"raw_name":"National Highway Traffic Safety Administration","name":"National Highway Traffic Safety Administration","id":345,"url":"https://www.federalregister.gov/agencies/national-highway-traffic-safety-administration","json_url":"https://www.federalregister.gov/api/v1/agencies/345","parent_id":492,"slug":"national-highway-traffic-safety-administration"}],"body_html_url":"https://www.federalregister.gov/documents/full_text/html/2003/11/04/03-27657.html","cfr_references":[{"chapter":null,"citation_url":null,"part":571,"title":49}],"citation":"68 FR 62417","comment_url":null,"comments_close_on":"2004-01-05","correction_of":null,"corrections":[],"dates":"You should submit comments early enough to ensure that Docket Management receives them not later than January 5, 2004.","disposition_notes":null,"docket_ids":["Docket No. NHTSA-1999-6550","Notice 3"],"dockets":[],"document_number":"03-27657","effective_on":null,"end_page":62421,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2003/11/04/03-27657.xml","html_url":"https://www.federalregister.gov/documents/2003/11/04/03-27657/federal-motor-vehicle-safety-standards-hydraulic-and-electric-brake-systems","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/03-27657?publication_date=2003-11-04","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2003-11-04/03-27657/mods.xml","not_received_for_publication":null,"page_length":5,"page_views":{"count":143,"last_updated":"2026-10-22 16:15:06 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2003-11-04/pdf/03-27657.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"2003-11-04","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2003/11/04/03-27657.txt","regulation_id_number_info":{"2127-AI63":{"issue":"200404","html_url":"https://www.federalregister.gov/regulations/2127-AI63/allow-roll-bar-during-brake-testing","title":"Allow Roll-Bar During Brake Testing","xml_url":"http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=200404&RIN=2127-AI63&operation=OPERATION_EXPORT_XML","priority_category":"Substantive, Nonsignificant"}},"regulation_id_numbers":["2127-AI63"],"regulations_dot_gov_info":{},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":62417,"subtype":null,"title":"Federal Motor Vehicle Safety Standards; Hydraulic and Electric Brake Systems","toc_doc":"Hydraulic and electric brake systems","toc_subject":"Motor vehicle safety standards:","topics":["Imports","Motor vehicle safety","Motor vehicles","Rubber and rubber products","Tires"],"type":"Proposed Rule","volume":68}