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The Haddon matrix, a tool for investigating severe bus and coach crashes
Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences, Surgery.
Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences, Surgery.
2003 (English)In: International Journal of Disaster Medicine, ISSN 1503-1438, E-ISSN 1651-3037, Vol. 1, no 2, 109-119 p.Article in journal (Refereed) Published
Abstract [en]

Objective: The aim of the study was to use the Haddon matrix to analyse crash and injury mechanisms in a severe coach crash, to investigate if a safety belt would have reduced injuries, and highlight the triage problem in a mass casualty situation during severe circumstances. Methods: A specific coach crash was chosen as the subject for the case study. All 34 occupants on board were interviewed about the crash, their injuries, and how they sustained their injuries. Medical records concerning ambulance and hospital treatment have been examined. Police reports and other documents concerning the vehicle, weather conditions and the road have been examined. The materials were structured in different cells according to Haddon's matrix. Results: The coach went off a road via a guard-rail and landed on the right side, in a 90° position right across a small river. The main reason for the coach to deviate from the road was strong and gusty side winds imposing lateral forces on the coach, making steering impossible. The impact from the crash was greatest in the front part of the coach, as this part fell 3 metres from the bridge guard-rail down to the river bank. The most frequent injury mechanism was that occupants were hit by other falling occupants. Most occupants would have benefited from having worn seat belts. Ten ambulances and one helicopter from different locations were called upon and the first ambulance arrived 30 minutes after the alarm (a 67-km drive). The helicopter, with an anaesthetist on board, arrived after 1 hour and 20 minutes (a 120-km flight). Nine occupants with moderate injuries and 10 seriously or severely injured occupants were transported by ambulance or helicopter to the hospital. Fifteen occupants, triaged as priority 3, were transported by a chartered coach to hospital where they arrived after about 3 hours. Conclusion: If 100% of the occupants had used a two-point belt, about two-thirds of the injured occupants with MAIS 2+ injuries would have sustained an injury reduction. A further injury reduction by roughly 20% could have been achieved by shifting from two-point belts to three-point belts. Triage of injured occupants could be different from normal practice because of the limited space inside a coach, and the use of ordinary equipment is not always possible inside a crashed vehicle. The fact that most of the side windows remained in position after the crash probably prevented many occupants from serious and fatal injuries caused by ejection or partial ejection.

Place, publisher, year, edition, pages
2003. Vol. 1, no 2, 109-119 p.
Keyword [en]
Haddon's matrix, bus, coach, injuries, prevention, severe crash, mass casualty
URN: urn:nbn:se:umu:diva-6560DOI: 10.1080/15031430310035272OAI: diva2:146229
Available from: 2007-12-14 Created: 2007-12-14 Last updated: 2010-04-14Bibliographically approved
In thesis
1. Occupant casualties in bus and coach traffic: injury and crash mechanisms
Open this publication in new window or tab >>Occupant casualties in bus and coach traffic: injury and crash mechanisms
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Background: The relevance of conducting this thesis is evident by the fact that bus and coach casualties have been “stubbornly stable” in Europe recent years and a need for investigating if a similar trend could be found in Sweden is therefore obvious. It was also important to add new knowledge to the bus and coach research in Sweden, since many areas were scarcely addressed.

Aims: To describe bus and coach occupants’ injuries, crash and injury mechanisms generated in a traffic environment based on data from the medical sector. Additional aims were to investigate the injury reducing effect of a 3-point belt, the effect of cross-winds, and crucial factors in the emergency- and rescue response.

Material and methods: Injury data analyses were based on a complete ten-year medical data set from a catchment-area with about 130,000 inhabitants. A number of crash studies with the scope in different crash phases were conducted by applying and elaborating the Haddon matrix as a framework. An additional framework, Protocol for Major Incidents was used in order to investi-gate the emergency- and rescue response to a severe coach crash.

Results: Between the first and second five-year period, the incidence of injured in non-crash in-cidents was increased by 24%. In non-crash incidents, 54% were injured; 2/3 while alighting from a bus or coach. The pre-crash factor cross-wind, in addition to vehicle design, vehicle speed and road friction, was investigated in ten crashes. It was confirmed that cross-wind, in relation to vehicle speed and slippery road conditions, needs more attention. The importance of goods load-ing and passengers’ position in the bus, was indicated by the fact that a displacement of the cen-tre of mass rearwards with 10% increased the necessary coefficient of friction with, on average 45%, which in many cases corresponded to dry road conditions. Three Swedish rollover crashes were analysed with regard to the injury outcome, mechanisms and the possible injury reduction for occupants using a safety belt. A considerable increase in safety for occupants belted with 3-point belts was shown through limiting interior contacts, occupant interaction and the possibility of ejection. Crucial post-crash factors in the emergency- and rescue response showed that ordi-nary ways of working and equipment are not always useful and proper equipment for lifting a coach body is essential in the case of a rollover. Finally, the communication between the hospitals is important, and the telephone systems may be overloaded by calls from worried relatives and media.

Conclusions: In non-crash events: Non-crash events constitute a majority of all bus and coach casualties with a high proportion of elderly female occupants among the MAIS 2+ injury cases. Boarding and, especially alighting causes many injuries to the lower extremities.

In the pre-crash phase: Cross-winds do affect the safety of buses and coaches and requires more at-tention. Seat belt usage among bus and coach occupants has to be increased.

In the crash phase: Rollover and ejection are the major causes behind serious and fatal injuries to bus and coach occupants, consequently, retentive glazing, pillars or rails need more attention. An upgrade from 2-point seat belts to 3-point seat belts yields an increase in the estimated injury re-duction from approximately 50% up to 80% for the MAIS 2+ casualties in a rollover crash.

In the post-crash phase: In order to be able to lift a coach body proper equipment originated from experience and development is essential in a rescue operation of a crashed bus or coach. Fur-thermore, to improve the emergency response inside crashed coaches proper methods originated from experience need to be developed.

Euro NBAP: Based on the results and conclusions generated in this thesis, a European New Bus and Coach Assessment Programme is suggested, which would provide bus and coach occupants with a assessment programme similar to the Euro NCAP.

Place, publisher, year, edition, pages
Umeå: Kirurgisk och perioperativ vetenskap, 2005. 160 p.
Umeå University medical dissertations, ISSN 0346-6612 ; 951
Surgery, bus, coach, aerodynamics, crash, non-crash, cross-wind, injuries, weight distribution, road friction, restraints, haddons matrix, prevention, severe crash, mass casualty, major incident, alighting, boarding, incidents, Kirurgi
National Category
Research subject
urn:nbn:se:umu:diva-482 (URN)91-7305-829-7 (ISBN)
Public defence
2005-04-22, Sal B, Tandläkarhögskolan, Norrlands Universitetssjukhus, Umeå, 13:00 (English)
Available from: 2005-03-24 Created: 2005-03-24 Last updated: 2009-11-09Bibliographically approved

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