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Caring highways and intelligent transportation systems

Hamilton Associates-Sany Zein, Eanson Ho
Insurance Corporation of British Columbia-Mavis Johnson
  • Technical Paper
  • 1996-25-0233
Published 1996-06-03 by ISATA - Dusseldorf Trade Fair in United Kingdom
Engineers now construct ""forgiving"" highways to protect errant motorists. For example, if you crash into an engineered roadside device your chances of survival are ten times better than if the device was immovable. Forgiving highways combined with safer vehicles have reduced the fatalities in Canada from over 7000 in 1970 to less than 4000 in 1995. The next generation of highways will have to address the major cause of road crashes; driver error. Such highways will be ""caring"" highways and they will attempt to keep motorists away from harm rather than simply minimizing the harm. The research for this paper identifies the degree of caring and forgiveness required of a safe highway. The potential solutions included: selected Intelligent Transportation Systems (ITS) such as, truck warning systems for rollover and runaway lanes, localized road weather information stations; technological enhancements such as, increased traction, more guidance, and pavement treatments; and behavior control at dangerous locations by speed photo-radar and intersection red- light cameras.
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Tire/Ice Friction Values

Royal Canadian Mounted Police-Scott Sanderson, Barry Chafe
University of British Columbia-Francis Navin
Published 1996-02-01 by SAE International in United States
Braking deceleration values in units of gravity on ice surfaces have typically applied to the locked and sliding wheel with a representative friction coefficient of 0.10 ascribed. Three years of testing winter roads for traction and braking capacities and controlled tests on an ice arena show that large percentage variations exist in friction values. The term ‘ice surface’ and its attributes is not well defined in the literature.Tests were run using different tires, at different temperatures, with and without ABS on smooth and rough ice surfaces and tabulated to show the differences in braking deceleration. The locked wheel values were compared with those values normally used by accident reconstructionists and indicate that care must be taken in selecting a representative value.
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Vehicle Traction Experiments on Snow and Ice

B. C. Ministry of Transportation and Highways-Connie Nicolletti
University of British Columbia-Francis Navin, Michael Macnabb
Published 1996-02-01 by SAE International in United States
Traction tests were run during February, 1993 and 1994. The snow tests were conducted at a fairly constant temperature of -2°C and the ice tests at an air temperatures ranging from -4 to -35°C. The test vehicles were a standard midsize automobile and highway maintenance gravel trucks.The automobiles on packed snow at -6°C has an average braking force coefficient of 0.35, a lateral force coefficient of 0.38 and a traction force coefficient of 0.20. The corresponding values for a straight truck are: 0.23, 0.35 and 0.15. An automobile on bare ice at -6°C has an average braking force coefficient and lateral force coefficient of 0.09, and a traction force coefficient of about 0.08. The valves for the truck on bare ice in the same order are 0.06, 0.07 and about 0.04.A relationship was developed between the average braking force coefficient, ambient temperature and the amount of standard highway winter aggregate used on the road. The influence of winter aggregate on ice gave an improvement of about 15 percent at a highway maintenance light application of…
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Hydroplaning and Accident Reconstruction

University of British Columbia-Francis Navin
Published 1995-02-01 by SAE International in United States
Automobile hydroplaning speed is affected by both the vehicle load on the tire and its inflation pressure, yet only inflation pressure is used in Horne's (1968) equation. He later (1984) made modifications to include a vehicle's tire footprint characteristics. Dunlap et al. (1974) studied the influence of water depth and tread depth on an automibile's hydroplaning speed. Empirical studies by Gallaway et al (1979) produced more conclusive hydroplaning speeds for both automobiles and Ivey et al (1984) for trucks.This paper uses an influence diagram to show how all the models are related. Using the model the author pursues a few vehicle design parameters that may be combined to make vehicles more prone to hydroplaning. Also, a set of rules is suggested that may be used during accident reconstruction to determine if a vehicle has in fact hydroplaned and the potential source.
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Elastic Properties of Selected Vehicles

Accident Research Team University of British Columbia-Francis Navin, Michael MacNabb, Grant W. Miyasaki
Published 1988-02-01 by SAE International in United States
Currently, there are very little data on the maximum crush experienced by vehicles during impact. Measurements of the maximum crush were made on selected vehicles to provide some insight on the amount of maximum crush during a collision and the extent of elastic rebound. Fourteen low speed barrier impacts were conducted at the Insurance Corporation of British Columbia and University of British Columbia (ICBC-UBC) test facility. In addition twelve measurements of maximum crush were obtained from Transport Canada high speed motion films of 30 mph impacts. To bolster the data, a paper by Hight provided thirty-three maximum crush measurements at impact speeds of 35 mph and one test at 40 mph. The combined data provided maximum crush information over a wide spectrum of impact speeds. The elastic crush which is the difference between maximum and residual crush was also determined.The amount of elastic crush on vehicles and the variation of elastic crush with residual crush was examined. Also, the elastic crush was expressed as a ratio of residual crush to maximum crush to more clearly…
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A Crash Test Facility to Determine Automobile Crush Coefficients

Accident Research Team University of British Columbia-Grant W. Miyasaki, Francis Navin, Michael MacNabb
Published 1988-02-01 by SAE International in United States
A low cost and low speed automobile crash test facility for full frontal impacts has been designed and constructed to determine vehicle crush characteristics. The function and operation of systems comprising the facility are discussed in this paper and include: Site layout and tow system arrangementTow system and test vehicle guidanceCrash barrierRelease mechanismsSpeed measurementRecording of the impact eventIn addition, the crash barrier is validated with preliminary test results.
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Crash III and Canadian Test Data

Accident Research Team, University of British Columbia-Francis Navin, Michael Macnabb
McGill Univ.-Neil Navin
Published 1987-02-01 by SAE International in United States
Increased awareness of road safety and a need for estimating vehicle speeds in accident reconstruction has spawned an ever increasing literature on speed estimation from vehicle damage. The theory used was quite simple and robust when first introduced in the early 1970s. The push of legislated fuel economy has produced a fleet of smaller and lighter cars which are structurally different from the vehicles of the early 1970s. The changing vehicle structure among other factors has reduced the robustness of the early analytical models introduced by Campbell (1972) and McHenry (1974). This paper goes back to a single variable, the slope of the impact speed/residual crush curve and derives a set of crush coefficients and their variance.
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