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Electronically Controlled Braking System Test Track Validation

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National Highway Traffic Safety Administration (NHTSA), DOT.


Notice of Research Activity.


The U.S. Department of Transportation (DOT) is seeking partners who have the potential of providing electronically controlled braking systems (ECBS) that can be used in an electronically controlled braking system test track evaluation. This notice describes criteria and tests that will be applied to each candidate system as part of the determination of fitness for inclusion in this evaluation. Manufacturers of systems that meet these criteria are invited to submit a description of their system and instructions on operation of the system to DOT.

Each system must satisfy the following criteria: (1) It must be designed to work in conjunction with standard, air-actuated drum brake mechanisms (i.e., the “foundation” brakes) currently used on the vast majority of commercial vehicles; (2) it must provide proportional electronic control of the foundation brake mechanisms in response to brake pedal inputs from the driver, and primary control of the foundation brakes must be via electronic signals and electropneumatic valves; (3) it must provide the antilock function as defined by Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems (49 CFR 571.121); (4) in the event of any single electrical or pneumatic failure in the control system, performance of the vehicle it is installed on must comply with the emergency brake stopping distance requirements of S5.7.2 of FMVSS No. 121; (5) the system must be designed to be compatible with conventional, pneumatically controlled braking systems (PCBS) to allow safe operation of tractor and trailer combinations where one of the units has ECBS and the other utilizes PCBS; and (6) the system shall be designed to be durable, reliable, and able to withstand the full range of environmental and operational conditions encountered in commercial vehicle operations.

Any system that meets the above criteria may be included in a DOT-sponsored test track study to evaluate the validity and reliability of its capability to electronically control braking systems on commercial motor vehicles. This planned test track evaluation was previously developed by a working group of brake experts formed by the Society of Automotive Engineers (SAE) under Federal Motor Carrier Safety Administration (FMCSA) Contract No. DTMC75-01-P-00022 as part of the Intelligent Vehicle Initiative. Various ECBS will be evaluated by SAE at the Transportation Research Center, Inc., located in East Liberty, Ohio. Various Class 7 and 8 heavy duty tractors and commercial trailers will be used in this evaluation of the validity and reliability of these systems' capability to electronically control braking systems on commercial motor vehicles under a cooperative agreement with the Federal Highway Administration (FHWA) Contract No. DTFH61-96-X-00015, Amendment No. 18.

The offeror understands that the system, if selected to participate in the test track evaluation, will be tested as provided. The analysis that is derived from this test track work will be made publicly available; however, the system will not be identified by manufacturer. The offeror shall in no way interfere with the procedures or personnel involved in conducting or managing the study.

Furthermore, (1) previous studies and research involving the device may be disclosed and provided to the Federal Government to assist in evaluating the “fitness” of the system for evaluation; (2) selection to participate in the test track study will NOT constitute an endorsement of the device by the Federal Government; and (3) involvement does not constitute a promise of any future relationship with the Federal Government.

The systems will be tested in an outdoor test track environment. A test matrix will be used to assess various configurations of ECBS-equipped vehicles as ECBS can be provided in various formats. The ECBS systems will be tested on a range of different Class 7 and 8 trucks, tractors, and commercial semitrailers equipped with new, burnished foundation brakes. To provide a baseline for comparison, vehicles will be tested first with conventional pneumatically controlled brake systems (PCBS) in accordance with FMVSS No. 121. This testing will include stopping distance and static brake timing tests. Vehicles will then be modified to incorporate ECBS, and the tests will be repeated. The tests with ECBS will evaluate a broad range of possible failure modes in order to assess partial system performance and compliance with the emergency stopping requirements of FMVSS No. 121.

As part of the testing program, the stopping performance of combination vehicles (i.e., tractor semitrailers) will be evaluated in order to determine compatibility between individual units with ECBS and PCBS.

The test results will be shared with the manufacturers of these systems. DOT is only interested in testing systems that are operationally ready.


Submit system descriptions on or before December 17, 2001.


All proposals should refer to Docket No. NHTSA-2001-10196 and should be submitted to Docket Management, Room PL-401, 400 Seventh Street, SW., Washington, DC 20590-0001. Docket hours are from 9 a.m. to 5 p.m. Monday through Friday. If you wish to receive confirmation of your written comments, please include a self-addressed, stamped postcard.

Proposals may also be sent by electronic submission. The electronic submission procedure is described in the Docket Management section of DOT's web site: http//

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Jim Britell, Mail Code NRD-13, Office of Vehicle Safety Research, NHTSA, 400 Seventh Street, SW., Washington DC 20590-0001, telephone (202) 366-5678.

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DOT has created a program titled the Intelligent Vehicle Initiative (IVI). The goal of the IVI program is to increase safety on the Nation's highways through the acceleration of the deployment of on-vehicle safety devices. One of the primary focus areas of the IVI is commercial motor vehicle stability. Start Printed Page 57507Further information on the IVI program may be found on web site​ivi. Additionally, DOT has the goal of reducing truck-involved fatalities by 50 percent by the year 2010. Additional information concerning DOT and its commercial motor vehicle safety goals may be found on web sites and

Electronically controlled braking is viewed as a technology that can provide shorter stopping distances (improved timing), improved dynamic brake force distribution, improved combination vehicle brake balance, self-diagnosis, and continuous brake monitoring. Because of the complexity of this technology (ranging from shorter stopping distances to improved vehicle brake diagnostics) and the various systems involved, it was suggested by the Truck Manufacturers Association at a public hearing sponsored by the National Transportation Safety Board in Nashville, Tennessee, August 31 through September 2, 1999, on Advanced Safety Technologies Applicable to Commercial Vehicles, that industry and Government work together in the preliminary track and operational testing of these braking systems. Additionally, electronically controlled brakes are an enabling technology whose benefits could extend to, and enhance, a number of vehicle braking and dynamic control system issues.

Numerous factors play a contributing role in causing heavy-duty tractor/trailer and passenger car crashes. Inadequate braking performance is a significant cause of commercial and vehicle crashes. The existing brake systems have performance limits. To more effectively address the brake-related issue of crashes (1) due to brake failures or defective brakes, (2) due to maladjusted and/or overheated brakes, and (3) where the heavy-duty vehicle is unable to stop in time, it is obvious to brake experts that some kind of adaptive electronic control system will be required. In 1993, brake manufacturer Bosch and truck manufacturer Scania introduced the first production-like brake by wire system for tractors/trucks and trailer/semitrailers. This technology is more commonly called Electronically Controlled Braking System (ECBS) for commercial vehicles. Other brake manufacturers and truck manufacturers have developed similar, although not identical, systems. Due to a lack of standardization of the tractor/trailer interface, production has been mostly limited to straight trucks and tractors. The next generation of electronic braking systems is well under way, taking advantage of the Controller Area Network technology, a joint development of Bosch and Intel of a data bus especially suited for the requirements in heavy duty vehicles.

DOT, NHTSA has addressed brake-induced instability by requiring ABS on newly manufactured tractors and trailers (FMVSS No. 121). The basic function of ABS is to monitor wheel speed and modulate the air pressure in the brake chambers in a manner to prevent wheel lock during severe braking. The successful introduction and acceptance of ABS by industry was only accomplished after many years of track testing and an extensive 4-year field operational test. The planned test track evaluation of ECBS solicited by this notice will be accomplished under a cooperative agreement between the FHWA and SAE. This evaluation is intended as a precursor to an on-the-road field operational test, which will include a motor carrier fleet in revenue generating service.

Technology Submission Instructions

Submit proposed system descriptions in English, including the Docket Number (NHTSA-2001-10196), to DOT's Public Docket Management Room at the previously listed address. The submission should include the following:

1. A description of the system, along with operating instructions.

2. The submission should be no more than five pages in length.

3. Any existing evidence of objective validity or reliability is encouraged to be submitted. This information DOES NOT count toward the 5-page length limit.

4. Three copies of your submission.

5. Your name, address, phone number, and E-mail address.

6. DO NOT submit your system at this time.

7. Applications, once submitted, become the property of DOT.

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Issued on: November 6, 2001.

Raymond P. Owings,

Associate Administrator for Research and Development.

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[FR Doc. 01-28621 Filed 11-14-01; 8:45 am]