VEHICLE SPEED AND SIDE ACCELERATION BEFORE AND AFTER SURFACE TREATMENT ON GRAVEL ROADS. AN EXPERIMENTAL STUDY

FORDONS HASTIGHETER OCH SIDACCELERATIONER FORE OCH EFTER YTBEHANDLING AV GRUSVAGAR

This study was made to determine if a special surface treatment (Y1G) on gravel roads results in smaller, larger or unchanged margins of safety for drivers. The margin of safety was determined by the proportion of the theoretically possible side acceleration used and the shortest theoretically possible stopping distance. In the investigation, carried out in two parts (before and after surface treatment), 18 drivers participated. They were to drive in their normal manner over 22 curves with different road widths, curve radii, and sight distances. Vehicle speed, side acceleration and road smoothness and friction were recorded during the test runs. The drivers, each driving a type of car familiar to him, made four runs. In the first one only registration was made. In the following three runs the drivers were asked to estimate how much faster they thought they could drive in each curve. Six of the drivers participated in both parts of the study. The results showed that the drivers drove approximately 2 km/h faster after the surface treatment. But the safety margin, despite the increase in speed, was greater after the surface treatment due to the improved friction. The probable reason the drivers did not utilize the higher friction for even more speed was that they did not want to expose themselves to higher side accelerations. In ratings following the driving, the subjects stated that the surface-treated road was safet, qucker and more comfortable, as well as "less harmful to the car" than ordinary gravel roads. /MSA/

• Corporate Authors:

  Swedish National Road and Transport Research Institute (VTI)

  Linköping,   Sweden  SE-581 95
• Authors:
  • Arnberg, P W
• Publication Date: 1976

Language

• Swedish

Media Info

• Features: Figures; References; Tables;
• Pagination: 38 p.

Subject/Index Terms

• TRT Terms: Acceleration (Mechanics); Gravel roads; Motor vehicles; Pavements; Safety factors; Smoothness; Speed; Surface treating; Traffic speed
• Old TRIS Terms: Pavement smoothness
• Subject Areas: Highways; Pavements; Safety and Human Factors;

Filing Info

• Accession Number: 00148737
• Record Type: Publication
• Source Agency: National Safety Council
• Report/Paper Numbers: Report Number 112
• Files: TRIS
• Created Date: May 11 1977 12:00AM