Braking characteristics of 400 heavy trailer combinations from Denmark, Finland, Norway and Sweden

Strandberg, Lennart

Affiliations

¹Swedish Road and Traffic Research Institute, VTI

Abstract

The braking characteristics have been studied on 100 heavy tractor/truck-trailer combinations in each of four countries. To achieve results representative for the four vehicle populations, police and vehicle inspection officers selected the vehicles randomly from the normal traffic flow on suitable roads.

Both the overall deceleration performance and the brake force distribution were measured directly by driving and dynometer tests. Also recorded were weight distribution$, brake and wheel size, push rod stroke, load sensing valve amplitude, etc.

Results include plots as well as linear correlation and regression coefficients of functions such as: load sensing valve adjustments versus relative load; deceleration versus control pressure; trailer versus truck deceleration performance; decelerationm easuredo n the road versusc omputations from dynometer data; brake force versus push rod stroke. Comparisons are made belween trailer types, load weight classesa, ndb etweenc ountriesc onsideringt heir distinct differences in legislative requirements.

Wheel lockup observations are related to simultaneous decelerationa nd control pressurem easurements. The deviations between ideal and recorded influence from load sensing devices are evaluated. No Antilock Brake System; ABS, was found in this vehicle sample (data from 1986–1987).

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Cited By (1)

Year	Entry
1996	Dowdell B, Vertsonis H, Smith S. Heavy vehicle in service brake requirements. In: Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles (ESV). May 13-16, 1996; Melbourne, Australia.1937-1953.