AN OPERATIONAL FIELD TEST OF LONG COMBINATION VEHICLES USING ABS AND C-DOLLIES--VOLUME I: FINAL TECHNICAL REPORT
The objective of this study was to evaluate the stability enhancing characteristics, practicality, reliability, maintenance costs and fleet personnel reactions to antilock braking systems (ABSs) and double-drawbar dollies (C-dollies). To do this, a fleet of double- and triple-trailer longer combination vehicles (LCVs) in actual commercial service was equipped with ABSs and with C-dollies and monitored for a period of one and one-half years. The fleet of test vehicles was distributed among five commercial fleets operating in the northwestern region of the country where the use of LCVs is most prevalent. The fleet accumulated 1.4 million miles on trips, and the individual units accumulated over 10.5 million unit-miles. All maintenance work done on the vehicles during the study was monitored, and the physical behavior of the vehicles on the road was measured with on-board instrumentation systems. Findings include the following: (1) ABSs can be expected to play a significant, stability-enhancing role in some ten to twenty severe braking events per 100,000 miles (roughly a year for a professional driver); (2) ABSs on LCVs can be powered through the brake-light circuit provided that several important conditions are met; (3) An ABS increases the total maintenance costs of an LCV by about 1% but reduces costs due to flat-spotting of tires; (4) The use of C-dollies on LCVs reduces rearward amplification in normal use; (5) Using C-dollies increases the total maintenance costs of an LCV by 3 to 5%, due mostly to increased tire wear; and (6) Drivers, mechanics and fleet managers favor the use of ABSs and C-dollies in LCV operations, and drivers especially favor C-dollies.
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Corporate Authors:
University of Michigan Transportation Research Institute
2901 Baxter Road
Ann Arbor, MI United States 48109-2150National Highway Traffic Safety Administration
1200 New Jersey Avenue, SE
Washington, DC United States 20590 -
Authors:
- Winkler, C B
- Bogard, S E
- Bowen, M A
- Ganduri, S M
- Lindquist, D J
- Publication Date: 1995-11
Language
- English
Media Info
- Features: Figures; Photos; References; Tables;
- Pagination: 167 p.
Subject/Index Terms
- TRT Terms: Antilock brake systems; Antilock brake systems; Brake lamps; Braking performance; Dollies; Electric circuits; Field tests; Fleet management; Maintenance management; Motor vehicles; Stability (Mechanics); Tractor trailer combinations
- Uncontrolled Terms: Fleets; Longer combination vehicles; Maintenance costs; Triple trailers
- Old TRIS Terms: Brake light circuits; C dollies; Double trailers; Test results
- Subject Areas: Highways; Motor Carriers; Vehicles and Equipment; I91: Vehicle Design and Safety;
Filing Info
- Accession Number: 00723759
- Record Type: Publication
- Source Agency: National Highway Traffic Safety Administration
- Report/Paper Numbers: UMTRI-95-45-1, HS-808 352
- Contract Numbers: DTNH22-92-D-07003
- Files: HSL, TRIS, ATRI, USDOT
- Created Date: Jul 3 1996 12:00AM