Bus Testing: Updates to Bus Testing Program Procedures and Policies, Clarifications, Technical Adjustments, and Other Program Updates

DEPARTMENT OF TRANSPORTATION Federal Transit Administration 49 CFR Part 665 [Docket No. FTA-2024-0012] RIN 2132-AB40 Bus Testing: Updates to Bus Testing Program Procedures and Policies, Clarifications, Technical Adjustments, and Other Program Updates AGENCY: Federal Transit Administration (FTA), Department of Transportation (Department or DOT). ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: The Federal Transit Administration (FTA) is proposing amendments to its bus testing regulation. The proposed changes will improve the efficiency of the testing program for stakeholders, enhance the value of bus testing reports for consumers, and assist in removing outdated test reports. DATES: Comments on this proposed rule must be received on or before August 25, 2026. FTA will consider comments received after that date to the extent practicable. ADDRESSES: Please submit your comments (identified by the agency name and DOT Docket ID Number FTA-2024-0012) by any of the following methods: Federal eRulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting comments. Mail: Docket Management Facility: U.S. Department of Transportation, 1200 New Jersey Avenue, SE, West Building Ground Floor, Room W12-140, Washington, DC 20590-0001. Hand Delivery or Courier: West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, between 9 a.m. and 5 p.m. ET, Monday through Friday, except Federal holidays. Fax: 202-493-2251. Additional Instructions: You must include the agency name (Federal Transit Administration) and Docket number (FTA-2024-0012) for this notice at the beginning of your comments. If you mail your submission and wish to receive confirmation that FTA received it, please include a self-addressed stamped postcard. Note that all comments received will be posted without change to https://www.regulations.gov. Note that any personal information provided will be available to internet users. Privacy Act: You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477), or you may visit https://docketsinfo.dot.gov. Docket Access: For internet access to the docket to read background documents and comments received, go to https://www.regulations.gov. Background documents and comments received may also be viewed at the U.S. Department of Transportation Docket Operations, 1200 New Jersey Avenue SE, West Building Ground Floor, Room W12-140, Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. FOR FURTHER INFORMATION CONTACT: For technical information, Marcel Belanger, Bus Testing Program Manager, Office of Research, Demonstration, and Innovation (TRI), (202) 366-0725, marcel.belanger@dot.gov. For legal information, Richard Wong, Attorney Advisor, Office of the Chief Counsel (TCC), (202) 366-0675, richard.wong@dot.gov. SUPPLEMENTARY INFORMATION: Table of Contents I. Executive Summary A. Purpose and Summary of Regulatory Action B. Statutory Authority C. Summary of Benefits and Costs II. Section by Section Analysis of Proposed Program Changes III. Request for Information IV. Regulatory Analyses and Notices I. Executive Summary A. Purpose and Summary of Regulatory Action The Federal Transit Administration (FTA) provides financial assistance to State and local agencies operating public transportation systems, covering eighty or eighty-five percent (80-85%) of a vehicle's capital cost, while the State or local government provides a fifteen or twenty percent (15-20%) matching share. As part of its stewardship of those funds, Congress directed FTA in 1987 to establish a bus testing program whereby new model buses would first be tested to ensure their ability to withstand the rigors of regular transit service before FTA funds would be spent on those vehicles. The FTA Bus Testing Program has evolved over more than three decades, during which it has been defined and shaped by a series of proposed and final rules, Federal Register notices, “Dear Colleague” letters, policy statements on FTA's Bus Testing website, and a few thousand responses to specific questions from transit vehicle manufacturers (TVMs). Additional details of current and historical policies and events are available on FTA's website at https://www.transit.dot.gov/research-innovation/bus-testing. FTA and other stakeholders have gained experience since the most recent Bus Testing Program final rule, which was published in 2016 (81 FR 50367). That final rule initiated the assignment of scores and pass/fail ratings to tested buses, as required by the Moving Ahead for Progress in the 21st Century Act (MAP-21; Pub. L. 121-141), as well as administrative changes. Today's NPRM proposes to build on this experience by modifying certain existing FTA Bus Testing Program procedures and policies to make them more effective, efficient, and clear. Some of the changes that FTA is proposing would increase the rigor of testing to address gaps, while others would relax certain program requirements to reduce the regulatory burden without weakening the overall effectiveness of the FTA Bus Testing Program. FTA is also seeking to increase flexibility within the Bus Testing Program to accommodate changes in bus technology that could require modification of some testing protocols. This NPRM is not a comprehensive re-statement of all FTA policies, procedures, and interpretations under the Bus Testing Program. Therefore, as a general guideline, policies, procedures, and guidelines that are impacted by any Final Rule that may result from this NPRM will be updated, while policies, procedures, and guidelines that are not impacted will carry forward with little or no change. Prior to publishing this NPRM, FTA engaged in a stakeholder listening session on September 8, 2022, about FTA's Bus Testing Program. In accordance with the Department's Guidance on Communication with Parties outside of the Federal Executive Branch (Ex Parte Communications), 1 FTA has added a memorandum summarizing the listening session to the docket for this rulemaking. Where FTA has incorporated stakeholder suggestions into its regulatory proposals, FTA discusses such suggestions in the corresponding sections below. 1  Available at: https://www.transportation.gov/regulations/memorandum-secretarial-officers-and-heads-operating-administrations. B. Statutory Authority Section 317 of the Surface Transportation and Uniform Relocation Assistance Act of 1987 (STURAA, Pub. L. 100-17) provided that no funds appropriated or made available under the Urban Mass Transportation Act of 1964, as amended, were to be obligated or expended for the acquisition of a new model bus after September 30, 1989, unless a bus of such model had been tested to ensure that the vehicle “will be able to withstand the rigors of transit service” (H. Rept. 100-27, p. 230). In subsection 317(b), Congress mandated seven specific test categories—maintainability, reliability, safety, performance, structural integrity, fuel economy, and noise—augmenting those tests with the addition of braking performance and emissions testing through section 6021 of the Intermodal Surface Transportation Efficiency Act of 1991 (Pub. L. 102-240). These requirements were subsequently codified at 49 U.S.C. 5318. Section 5318 has been amended several times throughout the years. Significantly, in 2012, Section 20014 of MAP-21 added new requirements to subsection 5318(e), Acquiring New Bus Models, including a bus model scoring system and a pass/fail standard based on the weighted aggregate score for each of the existing performance standards. Section 20014 retained the existing Bus Testing categories of maintainability, reliability, safety, performance, structural integrity, fuel economy, emissions, and noise in the existing 49 U.S.C. 5318(a). In response to MAP-21, FTA updated 49 CFR part 665 by issuing a new pass/fail standard and new aggregated scoring system. In addition, FTA made other revisions to the regulation, including requiring bus manufacturers to provide country-of-origin information for test unit bus components. Since then, FTA has had two reauthorizations that continued the Bus Testing Program, the Fixing America's Surface Transportation Act (FAST Act) (Pub. L. 114-94) and the Infrastructure Investment and Jobs Act (IIJA) (Pub. L. 117-58). While the FAST Act did not amend 49 U.S.C. 5318, Section 30008 of the IIJA amended 49 U.S.C. 5318 by adding subsection (f) Capital Equipment. This subsection adds that the bus testing facilities operated and maintained under 49 U.S.C. 5318 may use funds made available under this section for the acquisition of equipment and capital projects related to testing new bus models. Today's proposed rule does not address the minimum safety performance standards for public transportation vehicles authorized under 49 U.S.C. 5329(b)(2)(C) as referenced in 49 U.S.C. 5318(e)(1)(B)(ii). At this time, the safety performance standards in the National Public Transportation Safety Plan are voluntary standards. Additional details of the key steps in the creation and evolution of the Bus Testing Program are available at https://www.transit.dot.gov/research-innovation/program-history. C. Summary of Benefits and Costs The primary benefit of the proposed rule is that Bus Testing Reports less than 10 years old would more accurately reflect the safety, reliability, and other characteristics of today's bus models than older reports. Some bus manufacturers are using Bus Testing Reports from over 20 years ago to sell buses to FTA recipients while still complying with the current regulation. By requiring retesting, FTA can help ensure that Bus Testing Reports accurately represent bus models in production. In addition, FTA has improved testing requirements over the years, including testing related to safety; setting expiration dates would allow for bus testing that incorporates the improvements. For example, buses tested before 2010 were not subject to FTA's emissions and braking performance tests, which were added to the full testing requirements in that year. The primary cost of the proposed rule is the additional bus testing required after setting expiration dates for the reports. Figure 1 summarizes the economic effects of the proposed rule over the first ten years (from 2027 to 2036) in 2024 dollars. The proposed rule would have annualized costs of $2 million at a three percent rate discounted to 2024, and $1.7 million at a seven percent rate discounted to 2024. Figure 1—Summary of Economic Effects, 2027-2036 [$2024, discounted to 2024] Item Total (undiscounted) Annualized (3%) Annualized (7%) Benefits Unquantified Costs Testing recertification requirements $20,667,705 $1,968,313 $1,618,569 Lowered threshold for USM 824,467 73,800 56,307 Total costs 21,492,172 2,042,113 1,674,876 Net benefits Unquantified II. Section by Section Analysis of Proposed Program Changes Section 665.1 Purpose FTA is proposing non-substantive changes to this section. Section 665.3 Scope FTA is not proposing any changes to this section. Section 665.5 Definitions FTA is proposing to add and modify several definitions in this section. FTA seeks comments on proposed new definitions for failure, failure mode, and uncorrected failure. These terms are referenced in the description of certain tests in § 665.27(h), including the Reliability test and Safety test. For example, the Reliability test records all failures and breakdowns during testing. These terms are, therefore, very important in making pass/fail ratings of buses under test, but they are not defined clearly in the current regulation. FTA is therefore adding these definitions for clarity and to codify FTA's existing practice. FTA also seeks comments on whether a definition for corrected failure should be provided in the regulation. That term is not used in the regulatory text but is often used in Bus Testing determinations and Bus Testing Reports. FTA is considering defining corrected failure as: “Corrected failure means a failure mode that occurred during testing that was resolved through design, manufacturing process, quality control, or other improvement(s) by the manufacturer and successfully validated by sufficient subsequent testing. FTA may announce general guidelines for how it will validate that certain types of failures have been addressed, however each determination of whether a failure mode has been corrected will be made by FTA.” FTA is proposing definitions for four failure classes assigned during testing (“Class 1” through “Class 4”). It has been the Bus Testing Program's longstanding practice to utilize failure classes to describe the severity of a failure that occurs during testing. However, the four failure classes were not previously defined in the definitions section of the regulation. FTA is proposing to codify these failure classes to communicate the interpretations that have been used for testing for many years more clearly. FTA seeks comment on its proposed definition for recurring failure. Through experience administering the Bus Testing Program, FTA has observed that some bus models have repeated failures that, while they may or may not be individually serious, may cumulatively have an adverse effect on bus availability or life-cycle costs. This new definition would provide a way to call attention to repeated occurrences of the same failure mode. FTA proposes new definitions for baseline (bus) model and baseline report, and clarifying adjustments to the definitions for bus testing report and partial testing report. For example, FTA proposes amending the definition of bus testing report to clarify that a full testing report for a zero-emission vehicle includes all test procedures except for the Emissions test. These proposed definitions are added to clarify existing requirements and practice. However, FTA notes that these definitions would allow for the possibility that the Operator could create a complete “composite” test report by combining report “modules” corresponding to each test result ( e.g., performance, safety, durability) individually. FTA seeks comment on the potential advantages and drawbacks of combining the results of individual tests on related bus models to create a complete “composite” report on a bus configuration, compared to the current practice of expecting readers to consult the appropriate sections of baseline and partial test reports. FTA proposes to modify the definition of curb weight to clarify that curb weight does not include the weight of a driver for the Check-in test procedure described in § 665.27(a), because the Check-in procedure is performed on an empty bus. However, curb weight includes the driver's actual weight for the Structural Durability test and any other test that is performed with a driver. This is a clarifying change that would not result in a change to FTA's existing practice. FTA proposes clarifications to the definitions of major change in design, major change in components, and major change in configuration to bring them into consistency with longstanding practice. The updated definitions would better reflect FTA's established policy that additional testing of a modified bus model is required when the changes could result in obtaining significantly different test data compared to the baseline bus model. The updated definitions also would clarify that the changes described in the definitions are examples, rather than a complete list. These clarifications would not result in changes in practice. FTA proposes to delete the definitions for modified third party chassis or van and small bus manufacturer because those terms are not used in the regulatory text. FTA proposes to amend the definition for unmodified mass-produced van to require FTA to determine which models meet this definition. FTA would do so by developing and maintaining a list of which vehicle models are eligible for “unmodified mass-produced vehicle/van/chassis” designations. FTA believes that this would reduce uncertainty for recipients and TVMs regarding which vehicles are eligible for this designation. FTA seeks comments on the advantages and disadvantages of this proposal. FTA also proposes to clarify that such vehicles must be in the 4-year/100,000-mile useful life category, which is consistent with FTA's current practice and would not be a substantive change. FTA proposes to change the definition of unmodified third-party chassis to reflect the fact that original equipment manufacturers (OEMs) no longer publish official chassis modification guidelines. Under this proposal, buses built on chassis modified by the final stage manufacturer would generally require testing going forward. Some vehicle manufacturers have invested significant non-recurring engineering hours during testing of a bus model that have resulted in changes to the bus model that were validated through subsequent testing to have addressed the root cause of a failure mode. Due to this practice, FTA is proposing a new definition for non-recurring engineering hours and proposes that such hours should not be counted toward unscheduled maintenance hours, which also has a newly-proposed definition in § 665.5. FTA's rationale for this is that the riding public, recipients, and taxpayers are better served by a manufacturer taking time to resolve a design flaw than by FTA's regulation incentivizing the manufacturer to make a quick repair to be able to finish Bus Testing without exceeding the allowable number of unscheduled maintenance hours. This proposal relates to a stakeholder comment that FTA received during its 2022 Bus Testing listening session. This stakeholder stated that FTA's unscheduled maintenance hours standard should account for product improvements, noting that a manufacturer should not be penalized for making such changes. FTA seeks comments on the advantages of this proposed approach, as well as the potential risks up to and including whether manufacturers should be barred from making any modifications at all to a bus model during a test. FTA notes that the data obtained during testing of a bus model generally are not affected by the cosmetic condition of the bus. Therefore, FTA generally has allowed test buses to be submitted unpainted, with non-matching upholstery, etc., because these do not affect the data obtained. Similarly, FTA also has not counted as unscheduled maintenance hours any time needed to prepare and paint repaired components to restore their original appearance. However, FTA recognizes that transit operators typically will have to invest labor hours to restore the cosmetics of a bus that has experienced damage and repairs to body panels, doors, window frames, and similar components. FTA seeks comment, particularly from transit operators, on whether the definition of unscheduled maintenance hours should include time needed to restore the appearance of repaired bus components, and if it should, whether the unscheduled maintenance hour performance standards should stay the same or be adjusted to accommodate cosmetic repair time. The useful life category of a bus model is an essential concept in Bus Testing and FTA-funded vehicle procurements. FTA proposes to add a definition for useful life category that references the useful life categories defined in the current version of FTA Circular 5010. This term is synonymous with “service life category,” the term that had traditionally been used by the Bus Testing Program. FTA notes that “useful life category” is now the preferred term. Accordingly, FTA proposes replacing “service life category” with “useful life category” throughout part 665. In certain contexts where only the expected life of the bus is being discussed rather than the useful life classification, the word “category” may be omitted. None of these clarifications of terminology would represent a change in FTA's practice. FTA also proposes a minor clarification to the definition for final acceptance to specify that the vehicle has met its key bid specifications and the recipient has released FTA funding to the vehicle manufacturer. This change would codify FTA's longstanding interpretation of this term. FTA also proposes minor clarifications to other definitions, including automotive, gross weight, hybrid, new bus model, and regenerative braking system. Section 665.7 Certification of compliance FTA proposes adding a sentence in § 665.7(a) stating that a recipient may only certify compliance under § 665.7 based on a bus testing report that has not expired pursuant to § 665.13(g) at the time of initial contract award. If the base contract is awarded before the applicable bus testing report (or both the applicable baseline full bus testing report and partial testing report) expires, the recipient may exercise options on that contract, even after the report(s) expire. Since the original Bus Testing Regulation was published in 1989, § 665.7(b) has said that the recipient is responsible for determining whether a vehicle to be acquired requires full testing or partial testing or has already satisfied the requirements of part 665. However, since the earliest days of the Bus Testing Program, bus manufacturers, not recipients, have contacted FTA for determinations of testing requirements. This is now the way that all parties understand the program to work, and this approach makes sense for several reasons. First, the bus manufacturers know their vehicle in much greater detail than the typical recipient. Second, parties may view FTA as an impartial participant in the determination process. Third, having FTA make a single determination is more efficient than having potentially dozens of recipients coming to different conclusions about testing requirements at different times. To bring the regulatory text into consistency with the way that determinations of Bus Testing requirements have been made over the life of the Program, FTA proposes clarifying changes to § 665.7(b) and the addition of a new § 665.7(c). This new paragraph would convey that when a bus manufacturer or recipient is uncertain about whether testing is required, the bus manufacturer should be the party requesting FTA's review and determination of testing requirements for the bus model. Procedures for requesting a determination of Bus Testing requirements and a checklist of the information about the bus model that is required to make a determination are posted on FTA's Bus Testing website. FTA seeks comments on these proposed changes. Section 665.11 Testing requirements FTA is proposing to simplify the language in § 665.11(a)(5) to state that a test article bus must be substantially representative of subsequent production buses of that model. The existing part 665 language includes a short list of features of a bus that must be the same (“techniques, tooling, and materials”), but listing some features suggests that unlisted features ( e.g., “design”) are less important, and making a comprehensive list would be exceedingly long and would still miss potentially significant features. The proposed simplified language still would require that a test article bus must be representative of subsequent production buses of that model in all significant ways, including but not limited to the designs, key components, techniques, tooling, and materials. This proposed language would also allow FTA to make reasonable interpretations of this requirement in unforeseen circumstances, such as when a manufacturer implausibly claimed that a stack of multiple add-on structural patches to a test bus would be implemented in future production units. This proposed language would not be a change in policy, but rather a clarification of the policy that has been in effect since the program started. FTA proposes moving the existing requirement to identify the manufacturing point of origin of key components of a test bus out of § 665.11(a)(5) into a new § 665.11(a)(6), which also would use simplified language. For purposes of this requirement, key components of the bus still would include, but are not limited to, axles, braking systems, propulsion power systems, auxiliary power systems, primary energy storage and delivery systems, and any other components essential to the function of the bus model. This proposal would be a simplification of the regulatory text, not a change in policy. FTA is not proposing changes to § 665.11(c). However, FTA still encourages manufacturers to seek a full testing report as a baseline for future variants of a bus model built on a third-party chassis. FTA also notes that new bus models built on previously tested third-party chassis, even if eligible for partial testing, will usually require at least the Structural Durability test. The Structural Durability test alone represents 57 percent of the cost and 83 percent of the time required for a full test in the 7-year/200,000-mile useful life category. FTA notes that third-party chassis manufacturers typically make evolutionary updates to their chassis every few years. This has caused disruptions in the transit bus industry in the past, when every manufacturer building on a chassis with significant changes had to re-test their bus model(s) built on that chassis. Considering this, FTA is proposing to re-number existing § 665.11(d) as § 665.11(d)(1) and add a new § 665.11(d)(2). This new paragraph states that a bus model that has previously satisfied Bus Testing requirements would not require additional testing solely due to model year updates to an unmodified third-party chassis made by a third-party chassis manufacturer. This new paragraph also would keep open the possibility that FTA could issue an industry-wide determination requiring additional testing of affected bus models if major changes are made to a chassis. FTA proposes minor, non-substantive edits to § 665.11(e) for clarity. Some bus models have multiple significant modes of operation. For example, hybrid-electric buses may have significant engine-off driving range. FTA proposes a new § 665.11(g) that, subject to feasibility and practicality, would require testing of and reporting on all of a bus model's significant proposed modes of operation. FTA envisions that “significant” could include, but not be limited to, operational modes that the manufacturer touts in its advertising of that bus model's capabilities. FTA seeks comments on these proposals. Section 665.13 Test Report and Manufacturer Certification FTA is proposing clarifying edits to § 665.13(d). The data obtained in the course of Bus Testing often is valuable to transit research conducted or sponsored by FTA. FTA is proposing a modification to § 665.13(f) to allow FTA to use anonymized or aggregated Bus Testing data to support FTA-conducted or sponsored research. Data attributable to a particular bus model or manufacturer would still be limited to release in a bus testing report that the manufacturer has authorized for publication. FTA seeks comments on this proposal. FTA is proposing a new § 665.13(g), which would provide that full and partial bus testing reports shall expire 10 years after the date of publication. Several bus models are being sold to FTA recipients based on bus testing reports that are decades old. FTA believes it is highly likely that most if not all bus models will have undergone significant changes over such a long time. Manufacturers often make improvements to designs, specifications, materials, and suppliers. Even if each of those changes is not significant enough to trigger partial testing by itself, the accumulation of many small changes over time results in a potentially significant overall change. In addition, bus technologies and components are continually evolving. Third-party chassis manufacturers implement minor changes regularly and may implement more significant changes every few years, and sometimes do not notify bus manufacturers of these changes. Manufacturers and suppliers may have changes in corporate priorities, management, and workers. Furthermore, FTA updates its testing and reporting procedures from time-to-time, such as with the introduction of the Emissions and Braking Performance tests, or the implementation of scoring and pass/fail ratings. Bus testing reports do not reflect changes in test procedures implemented after they were published. For each of these reasons, FTA believes that it is appropriate to propose that full and partial bus testing reports should expire after 10 years. Stakeholders that participated in the September 8, 2022, listening session did not express concerns with having bus testing reports expire after 10 years. FTA proposes that the 10-year expiration provision would become effective three years after publication of the final rule to give manufacturers sufficient time to plan and implement their testing schedules. FTA seeks comments on the advantages and disadvantages of implementing report expiration dates, whether the time until expiration should be the same or different for different types of buses, what the appropriate time(s) until expiration should be, and whether three years is an appropriate period to phase in expiration dates for Bus Testing Reports. Section 665.21 Scheduling Proposed § 665.21(a) no longer would direct manufacturers to submit test requests to the FTA Bus Testing Program Manager. Instead, it would direct test requests to be submitted in the manner and form prescribed by FTA. FTA has historically included applicable instructions and a checklist on FTA's Bus Testing website. Since April 2022, the Bus Testing website has directed submitters to use the FTA Bus Testing Portal to submit requests for determinations of Bus Testing requirements and requests for FTA authorization to begin testing a bus model. The Portal is a web-based system that provides greater structure, clarity, convenience, and consistency for manufacturers to submit their requests and for FTA to respond to them more efficiently. The intent of the revised § 665.21(a) is to require submitters to use the Portal, while allowing flexibility for FTA to enhance, migrate, or replace the Portal if that should be needed in the future. The website lists alternative ways to contact FTA for any unusual inquiries that are not suitable for submission using the Portal. FTA has proposed minor edits to paragraphs (b) through (d) to increase clarity and for consistency with current practices. For example, the Operator is able to view authorizations in the FTA Bus Testing Portal, so manufacturers now only need to reference an FTA testing authorization when scheduling a bus for testing. In addition, FTA has removed an outdated URL for the Operator's website and stated that FTA will link the Operator's website from the FTA Bus Testing website. Section 665.23 Fees FTA proposes to amend § 665.23(c) to clarify that once the manufacturer's fee has been expended, the Operator must seek FTA approval to continue testing only in cases where the Operator has concerns about continuing the test. In other cases, testing may continue using the Bus Testing Program's share of the testing fee without FTA approval. This proposed change would conform the regulation to FTA's existing practice. Since FTA began issuing pass/fail ratings, a small number of bus models have started and been withdrawn from testing multiple times due to poor performance of the test bus. To prevent manufacturers from conducting multiple taxpayer-subsidized tests until a bus obtains a passing score, and to encourage manufacturers to ensure that their bus model is ready for the rigors of testing and transit service, FTA is proposing a new § 665.23(d). This new provision would require a manufacturer to pay the total applicable full or partial testing fee up-front when resubmitting a bus model that had previously started and been withdrawn from testing. When, or if, that bus model obtains a passing score, the bus manufacturer will be reimbursed upon publication of the report for FTA's share of the testing fee for the test that resulted in a published passing report. Under this proposal, manufacturers would continue to pay only the manufacturer's share of the testing fee the initial time a bus model is submitted for testing. The Time and Fee Schedule for testing reflects the 20 percent manufacturer's share of the testing fee set forth by statute in 49 U.S.C. 5318. Figure 2 illustrates the manufacturer's contribution to the testing fee under various scenarios applicable to the proposed new provision in § 665.23(d). Figure 2 reflects FTA's assumption and experience that a manufacturer will never approve publication of a Bus Testing Report with a failing score, since manufacturers have the option to withdraw a bus from testing at any point prior to publication of the report. Figure 2—Manufacturer's Share of Bus Testing Fee on Initial and Repeat Submission(s)   Initial submission Second or later submission Manufacturer's share of testing fee: Due at contract signing 20% 100%. If bus is withdrawn Already-incurred portion of manufacturer's share shown above Already-incurred portion of manufacturer's share shown above. Net, upon publication of passing report 20% * Manufacturer's share from prior attempt(s), plus 20% of the total fee for the passing attempt. * * Additional charges may be assessed to offset actual incremental costs such as for alternative fuels, non‐routine maintenance, extraordinary repairs, Operator's observation of maintenance performed by the manufacturer, and extended testing required by FTA to validate bus modifications. Section 665.25 Transportation of Vehicle FTA is proposing minor changes to this section to clarify that manufacturers are responsible for transporting their vehicle to and from the Bus Testing Center as needed at any point in testing, including if a manufacturer withdraws, re-submits a vehicle, or both. This is a clarification, not a change. FTA anticipates that in most cases, transportation of a test vehicle will occur only prior to the start of testing, and at the completion of testing. Section 665.27 Procedures During Testing FTA proposes to clarify that inspections and checks that the Operator performs under § 665.27(a) may occur during testing, and not only “upon receipt” of a bus approved by FTA for testing. This is not a change, but rather a clarification of existing practice. FTA is proposing a new § 665.27(a)(5) directing the Operator to identify any safety concerns as part of its pre-test inspection of a test bus. The Operator already does this informally, but this new provision would enable the Operator to increase the rigor and authority of its safety inspection. Similarly, FTA is proposing a new § 665.27(a)(6) directing the Operator to identify any concerns with the fundamental suitability or fitness of the bus for transit service. Examples could include, but are not limited to, a bus that is not equipped with a reasonable number of seats or has an impassable aisle. Section 665.27(b) currently prevents the start of testing and requires FTA authorization to begin testing if a bus does not comply with the checks enumerated in § 665.27(a). Through experience administering the Bus Testing Program, FTA has found that the issues enumerated in paragraph (a) sometimes arise and require correction not only before testing starts, but also during testing. Accordingly, FTA is proposing to expand § 665.27(b) to pause testing and require FTA authorization to continue a test if a bus is found to be non-compliant with those requirements at any time during testing. This is not a change, but rather a proposed codification of existing practice. FTA would retain its existing practice that testing may begin again after five business days if FTA does not provide a response. FTA proposes minor edits to § 665.27(e) for clarity and to state that the Operator shall investigate occurrences of unauthorized maintenance or repairs with FTA, if necessary. This is not a change to FTA's current practice. Manufacturers sometimes request permission to make one or more modifications to a bus in testing to address problems that were uncovered by testing. FTA historically has allowed reasonable modifications to test buses but has required that the modifications are validated with sufficient testing after the modification has been made, and that the modification is implemented in future production buses of that model and is documented in the Bus Testing Report. All of those requirements are necessary to ensure that Bus Testing Reports contain information that is representative of the buses that FTA recipients will obtain. Accordingly, FTA is proposing to incorporate these procedures into § 665.27(f), which pertains to when a manufacturer requests to make a modification to a bus already in testing to address a problem discovered during testing. These proposed edits are not new policies; rather they would clarify and standardize FTA's existing procedures. FTA notes that allowing manufacturers to correct a problem with a root-cause fix and validate that change during testing may benefit all stakeholders by resulting in better production buses. However, FTA alternatively requests comments on whether modifications to a test bus should be prohibited once a bus has begun testing. FTA seeks comment on its proposed updates, enhancements, and modifications to the Bus Testing protocols and procedures in § 665.27(h), as discussed below. FTA proposes edits to § 665.27(h) to clarify that the Operator must develop detailed procedures for performing the tests described in this part, and that these test procedures must be approved by FTA and be publicly available. FTA may seek stakeholder input before approving significant changes to the test procedures. This is a proposed clarification of the longstanding practice of the Bus Testing Program, not a change. In addition, FTA proposes clarifications to § 665.27(h), which respond to circumstances that FTA has addressed on a case-by-case basis in previous unusual testing situations. These proposed changes would clarify that FTA and the Operator may modify details of test procedures and reporting on a case-by-case basis to the extent necessary to meet the intent of Bus Testing for a bus model with new technologies, features, capabilities, or limitations. Typically, the vehicle manufacturer would have an opportunity to decide whether to proceed with testing under the modified procedures and reporting proposed by FTA and the Operator in such cases. In these cases, which are expected to be rare, bus testing reports would clearly flag and discuss any such ad hoc modifications to the testing procedures, performance standards, or potential service limitations. As an example, a recipient might have a public transportation need that can be fulfilled by a vehicle that has a top speed of less than 45 mph. If that vehicle were submitted for FTA Bus Testing, it would not be able to meet the Safety test performance criteria of navigating the lane change maneuver at 45 mph, but if it could safely negotiate the lane change course at its top speed, its stability at the highest speed it could attain would be validated and there would be little concern with the vehicle rolling over in service. Therefore, FTA could determine in that case that this vehicle passed the Safety test. The bus testing report would include an indication on the cover of the vehicle's limited top speed, and a discussion of that limitation within the report. FTA is proposing several adjustments to the Maintainability test described in § 665.27(h)(1) to allow greater flexibility for buses that have non-standard designs, components, or capabilities. FTA proposes revising the language regarding removal and reinstallation of certain components to specify that this requirement applies to a representative sample of bus components that are likely to require removal and replacement during the useful life of the bus. Examples of components that would be removed and replaced could include the transmission, engine, propulsion motor, alternator, starter, high-voltage and low voltage battery, and windshield wiper motor. The proposed language would allow flexibility for bus models with novel technologies—for example, the Operator might remove and replace the fuel cell on a fuel cell powered bus, since that component is analogous to an engine on a conventional bus. FTA is also proposing to specify that required repair actions must be reported in the Maintainability test during any type of partial testing, not just when the Structural Durability test is performed. This would be a change from prior practice. To date, repairs have only been reported when Structural Durability testing is performed. However, servicing and repairs may be required during any of the tests that are performed. FTA believes that information about these repair actions is necessary for recipients to have a complete understanding of the maintainability of a bus. Accordingly, FTA is proposing that servicing, preventative maintenance, and repairs that are required at any point in a full or partial test of a bus model must be reported. For example, if a bus is submitted for the relatively brief Fuel Economy test and the transmission fails on the dynamometer while simulating normal operation, FTA believes that recipients would find that information valuable. Finally, FTA proposes to delete the sentence regarding the Operator seeking advice from the bus manufacturer because it is redundant with the following sentence regarding the Operator carrying out routine and corrective maintenance in accordance with the manufacturer's specifications and guidance. FTA is proposing to change the performance standard for unscheduled maintenance (USM) hours in § 665.27(h)(1)(ii) to make the required maintainability more consistent across useful life categories. Under FTA's current regulation, the performance standard is 125 hours regardless of the useful life category of a bus. As depicted in Figure 3 below, FTA proposes to change this performance standard to a number that decreases as the useful life decreases. The proposed standards are “round” numbers that result in a maximum USM hours rate that is more consistent and increases only slightly as the useful life gets shorter. Under the current performance standard, the USM hours rate for the 12-year useful life category is 10.42, which is significantly lower than the rate of 31.25 for the 4-year useful life category. The rates under FTA's proposal are much more consistent and equitable across useful life categories. FTA believes that this proposal is appropriate, as it serves to mitigate the greater weight of a single failure on the overall number of USM hours during a shorter test. Figure 3—Existing and Proposed Unscheduled Maintenance Hour Limits Useful life category (years/miles) 2016 Final rule USM limit (hours) 2016 Final rule USM rate (hours/year) Proposed USM limit performance standard (hours) Proposed USM rate (hours/year) 12/500,000 125 10.42 125 10.42 10/350,000 125 12.50 110 11.00 7/200,000 125 17.86 80 11.43 5/150,000 125 25.00 60 12.00 4/100,000 125 31.25 50 12.50 FTA analyzed historical data about the performance of buses on the Maintainability test and has determined that the proposed changes would not result in a significant impact to the passing rate of buses on the Maintainability test. As shown in Figure 4, only a minimal number of buses (shown with columns) that performed poorly in the test exceeded the proposed new USM hour limits (shown with horizontal lines), and those were from prior to the implementation of pass/fail testing in 2016. FTA notes that a small number of buses have been withdrawn from pass/fail testing because they were having extensive failures and were likely to exceed the existing 125-hour limit. Figure 4—Unscheduled Maintenance Hours on 4-10-Year Buses (2012-July, 2023) EP26JN26.052 FTA also proposes that the USM hours limit must apply to any test, not just a full test, because failures that occur and repairs that are required during short-duration and relatively low-stress tests are at least as concerning as those that occur during the high-stress Structural Durability test. FTA proposes minor edits to the Reliability test in § 665.27(h)(2) to clarify that the test includes failures that occur during any test, including partial tests that do not include the Structural Durability test. FTA and the Operator would adjust their determinations of Bus Testing requirements and reporting, respectively, to include Reliability testing in all determinations and bus testing reports going forward. FTA also proposes to revise the Reliability test description to remove the definition of Class 1 and Class 2 failures. These failure classifications have been moved to the definitions section of the regulation, as FTA believes this is the most natural place for readers to find defined terms. FTA also proposes to revise the Reliability performance standard to remove the reference to Class 1 failures, as these failures are addressed in the Safety test. FTA proposes expanding the Safety test in § 665.27(h)(3)(i) to require a description in the bus testing report of any safety concerns on a bus model, and the actions taken to correct those concerns. There have been several cases where the Operator has refused to begin or resume testing a bus model until its manufacturer corrected safety deficiencies. FTA believes that it is necessary to include this information in the bus testing report for recipients to have a complete understanding of the safety of a bus. FTA is proposing to simplify the language of the double lane change test in § 665.27(h)(3)(ii) to state that safe execution of the maneuver must be at 45 mph to pass. This would not be a substantive change from the current regulation, which requires that the maneuver must occur at “no less than 45 mph.” FTA notes that the Operator's detailed Safety test procedure defines unsafe execution of the double lane change test as unstable vehicle handling or a wheel coming off the ground. FTA also notes that the top speed of certain limited-performance vehicles is under 45 mph. In such cases, the proposed new language in § 665.27(h) regarding new technologies, features, capabilities and limitations would enable FTA to adjust the performance standard for limited-performance vehicles to negotiating the lane change course safely at the lesser of 45 mph or the vehicle's top speed. FTA is also proposing to delete unnecessary detail regarding the dimensions of the lane change course, which are described in the test procedure document developed by the Operator. FTA is not proposing to change the procedure or dimensions of the lane change test. In § 665.27(h)(3)(iii), FTA is proposing to clarify FTA's current practice, which is that the performance standard for stopping distance is “based on” the requirements of FMVSS 105 or 121 due to the complexity of those regulatory requirements. The descriptions of the Safety test in § 665.27(h)(3)(iv) formerly included definitions of failure classes and corrected failures. As explained in the discussion above, FTA proposes moving those definitions to § 665.5. In § 665.27(h)(4), FTA proposes modifying the Performance test description regarding a vehicle's maximum acceleration and speed because higher-performing vehicles may not need to be accelerated during this test to the top speed they can reach. FTA also proposes that the performance test may calculate a vehicle's acceleration, speed, and gradeability capability in situations in which direct measurement of such values is not feasible. FTA proposes several changes to the Structural Integrity tests in § 665.27(h)(5). FTA proposes removing unnecessary and restrictive detail from the description of the Structural Integrity tests and adding clarifying details, and renumbering subparagraphs to conform to Federal Register standards. Names of the individual test procedures have been added to make the section easier to read. FTA proposes to clarify the test description and the performance standards for the Structural Distortion test in § 665.27(h)(5)(i)(A). The language in the existing regulation saying “all four wheels” is not compatible with motorcoaches, articulated buses, or any vehicle with other than four wheels. The change to “each wheel” would make the regulatory text consistent with longstanding practice. FTA notes that the passenger escape mechanisms that must remain operable under§ 665.27(h)(5)(i)(A)( 2 ) include a wheelchair lift or ramp. FTA also proposes a new safety performance standard for the water leak test: No uncorrected safety hazards during the test. Because of the wide range of potential hazards from water leaking into unintended places on a bus, neither FTA nor the Operator can anticipate all the possible hazards that may occur, so the performance standard proposed in the regulatory text is non-specific. FTA anticipates providing examples of potentially failing safety hazards in the test procedure documents, and on the FTA Bus Testing website. Examples could include, but are not limited to, water shorting out an electrical power or control circuit and causing a fire, smoke, or other improper functioning of safety-critical systems, or water making the bus aisle extremely slippery. FTA is only proposing to fail buses for significant water leakage that could impact the safety of occupants or the operation of the bus, and that is not successfully corrected and validated by successfully repeating the water leak test. Based on experience, FTA anticipates that this performance stand