Project: The Effects of Belted Passengers on Roll-Over Protection in Buses

Reference: S0023/VE

Last update: 09/09/2003 12:28:26


The objective of this research was to investigate the effects of belted and unbelted occupants on coach rollover motion using analytical methods supported by appropriate full-scale testing of coach body sections.


The touring coach is one of the safest means of transportation. Nevertheless, when accidents do occur, particularly those involving rollover, multiple injuries and fatalities can result. Previous research investigated the strength of coach structures during rollover tests. These tests along with other international work resulted in the production of the first harmonised bus/coach standard - UNECE Reg 66. Testing to this standard can be expensive and so a review of computer modelling techniques was started approximately 5 years ago. Recent changes to regulations has seen a wider uptake of seatbelts in coaches and this has raised some concern over the modified roll dynamic due to the static (i.e. restrained) mass of seat-belted occupants. This prompted the review to consider also the effect of occupants on coach rollover but very little was known on the effects in the UK. This research was able to provide objective data by carrying out full-scale rollover tests on coach sections representing the no-occupant, unrestrained-occupant and restrained-occupant situations. These tests were then modelled using finite element techniques.


Cranfield University
The Cranfield Centre for Logistics and Transportation, Cranfield, Bedford, MK43 OAL
01234 751122

Contract details

Cost to the Department: £50,000.00

Actual start date: 01 June 2001

Actual completion date: 30 November 2001


Investigation Into the Effects of Belted Passengers on the Rollover Protection of Coaches
Author: Cranfield Impact Centre Limited
Publication date: 01/05/2002
Source: Contact

Summary of results

  1. Full-scale rollover tests enabled the generation and validation of a numerical computer model. This was then used to examine several different occupant loading configurations which identified that passenger mass effects could make a significant contribution to the rollover characteristics.