Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study MRR 12/2009 Designed by: Publication Unit, MIROS Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study MRR 12/2009 Designed by: Publication Unit, MIROS Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study MRR 12/2009 Designed by: Publication Unit, MIROS Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study Ahmad Syukri Mohammad Mahafiz A Rahim Wong Shaw Voon Radin Umar Radin Sohadi Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral 43000 Kajang, Selangor Darul Ehsan Tel +603 8924 9200 Fax + 603 8733 2005 WebsiteSingle www.miros.gov.my Vehicle Accidents Email [email protected] Involving Trees in Malaysia – A Preliminary Study MRR 12/2009 Designed by: Publication Unit, MIROS Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study Ahmad Noor Syukri Zainal Abidin Ahmad Syukri Mohammad Mahafiz A Rahim Wong Shaw Voon Radin Umar Radin Sohadi Mohammad Mahafiz Abdul Rahim Wong Shaw Voon, PhD Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral 43000 Kajang, Selangor Darul Ehsan Tel +603 8924 9200 Fax + 603 8733 2005 Website www.miros.gov.my Email [email protected] Radin Umar Radin Sohadi, PhD Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral 43000 Kajang, Selangor Darul Ehsan Tel +603 8924 9200 Fax + 603 8733 2005 WebsiteSingle www.miros.gov.my Vehicle Accidents Email [email protected] Involving Trees in Malaysia – A Preliminary Study MRR 12/2009 Designed by: Publication Unit, MIROS Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study MRR 12/2009 Designed by: Publication Unit, MIROS Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study Ahmad Syukri Mohammad Mahafiz A Rahim Wong Shaw Voon Radin Umar Radin Sohadi Ahmad Noor Syukri Zainal Abidin Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral 43000 Kajang, Selangor Darul Ehsan Tel +603 8924 9200 Fax + 603 8733 2005 WebsiteSingle www.miros.gov.my Vehicle Accidents Email [email protected] Involving Trees in Malaysia – A Preliminary Study MRR 12/2009 Designed by: Publication Unit, MIROS Single Vehicle Accidents Involving Trees in Malaysia – A Preliminary Study Ahmad Noor Syukri Zainal Abidin Ahmad Syukri Mohammad Mahafiz A Rahim Wong Shaw Voon Radin Umar Radin Sohadi Mohammad Mahafiz Abdul Rahim Wong Shaw Voon, PhD Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral 43000 Kajang, Selangor Darul Ehsan Tel +603 8924 9200 Fax + 603 8733 2005 Website www.miros.gov.my Email [email protected] Radin Umar Radin Sohadi, PhD Mohammad Mahafiz Abdul Rahim Wong Shaw Voon, PhD Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral 43000 Kajang, Selangor Darul Ehsan Tel +603 8924 9200 Fax + 603 8733 2005 Website www.miros.gov.my Email [email protected] Radin Umar Radin Sohadi, PhD, P Eng Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral 43000 Kajang, Selangor Darul Ehsan Tel +603 8924 9200 Fax + 603 8733 2005 Website www.miros.gov.my Email [email protected] Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study Ahmad Noor Syukri Zainal Abidin Mohammad Mahafiz Abdul Rahim Wong Shaw Voon, PhD Radin Umar Radin Sohadi, PhD, P Eng i MIROS © 2009 All Rights Reserved Published by: Malaysian Institute of Road Safety Research Lot 125-135, Jalan TKS 1, Taman Kajang Sentral, 43000 Kajang, Selangor Darul Ehsan. Typeface: Myrid Pro Light Size: 11 pt / 15 pt For citation purposes Ahmad Noor Syukri ZA, Mohammad Mahafiz AR, SV Wong, Radin Umar RS (2009), Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study, MRR 12/2009, Kuala Lumpur: Malaysian Institute of Road Safety Research. DISCLAIMER The information contained in the report is restricted and/or privileged information and is intended only for authorised screening and/or confidential presentation of MIROS’s discretion. This report should not be disseminated, modified, copied/plagiarised or action taken in reliance upon it, unless permitted by MIROS. None of the materials provided in this report may be used, reproduced or transmitted, in any form or by any means, electronic or mechanical, including recording or the use of any information storage and retrieval system, without written permission from MIROS. Any conclusion and opinions in this report may be subject to reevaluation in the event of any forthcoming additional information or investigations. MIROS declares that all the inquiries which MIROS believes are necessary and appropriate and that nothing significant which MIROS regards as relevant, have to MIROS knowledge, been withheld from the report. Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study Project Contributors Sharifah Allyana Syed Md. Rahim Rohayu Sarani Akmalia Shabadin Hizal Hanis Hashim iii Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study Contents Acknowledgements vii Abstract ix 1. Introduction 1 2. Methodology 3 2.1 Catchment Area 4 2.2 Data Set 4 2.3 Data Analysis 6 3. Results & Discussions 7 3.1 Drivers Data 7 3.1.1 Demographic data of the drivers 8 3.1.2 Casualties and injuries of the drivers 9 3.2 Comparison of Tree Related Traffic Collisions for Year 2006 and 2007 in Malaysia 11 3.3 Identified Crucial Factors in Tree Related Collision for Year 2006 and 2007 in Malaysia 12 3.3.1 Day and time factors 14 3.3.2 Road environment factors 16 3.4 In-depth Analysis of MIROS Crash Investigation 23 4. Conclusion 31 References 34 Appendix 36 v Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study Acknowledgements The authors would like to express their gratitude to Prof Dr Ahmad Farhan for his support and advice. We also would like to thank the Royal Malaysian Police (PDRM) for their considerable support and cooperation particularly during the data collection process. vii Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study Abstract The study was conducted to investigate single-vehicle accidents involving trees in the Malaysia from the police national database (Pol 27) and the Malaysian Institute of Road Safety Research (MIROS) in-depth crash analysis data. The Pol 27 provided information on tree-related traffic collisions that occurred in year 2006 and 2007, while the MIROS crash investigation data covered 19 cases between October 2007 and September 2008. The accumulation of cases in 2006 and 2007 recorded fatal cases as the highest (39%) in terms of the severity level. Factors which were available in Pol 27, viz., day, time, road geometry, numbers of carriageway, pavement quality and road shoulder width. A Mann-Whitney U Test was performed to identify any pattern variation on six crucial factors between the two years of Pol 27 data. From the Asymptotic Significance value, it was revealed that numbers of carriageway and pavement quality factors display significant variation between the data from the two years. Cross tabulation analysis and chi-square test were also performed to determine the odds ratio value and chi-square value, respectively. From the chi-square test, only time and road shoulder width factors were found to be associated to injury severity level. Odds ratio value resulted from cross tabulation revealed only time, number of carriageways, pavement condition and road shoulder width recorded significant values. Night-time (time), dual carriageways roads (number of carriageway), wavy and holed condition roads (pavement quality), and roads with road shoulder width below 2.5 m (road shoulder width) were identified as the more significant variables in fatal cases. Other crucial factors extracted from MIROS in-depth crash investigation analysis were tree diameter, clearance zone width, frontal/side collision mode, and proportion of occupants being ejected. The result indicated that vehicle occupants were at a higher risk of getting severely or even fatally injured when involved in a side collision with trees. Fatal occupants constituted 56% of the total number of ejected occupants while fatal and severely injured occupants of the non-ejected recorded significant values, 29% and 44%, respectively. ix Single-Vehicle Accidents Involving Trees in Malaysia – a Preliminary Study 1. Introduction Malaysia is considered as a country with a high number of road traffic collisions. Many measures have been implemented to reduce the number of fatalities on the road every year. Currently, single-vehicle accidents or run-off-road (ROR) collisions occurring on Malaysian roads are of significant concern. Based on the accident data collected by the traffic police in Malaysia (Pol 27), single-vehicle accidents constituted a significant proportion in serious injury cases (25.7%) and fatal cases (38.6%) of the total road traffic collisions in 2006. However, single-vehicle accidents, up to now, have not been comprehensively investigated for the Malaysian scenario. While referring to the European statistics, according to Naing et al. (2007), as cited from Collin (2000), it is reported