Factors Associated with Motorcylists' Safety at Access Points along Primary Roads in Malaysia
Författare
Summary, in Swedish
Popular Abstract in English
More than 50% of road accident fatality victims in Malaysia are motorcyclists, numbering more than 4,000 fatalities per year. The aim of this thesis was to investigate motorcyclists’ road safety problems in general in Malaysia, and narrow down the focus to the most salient road infrastructure related risk factors. After identifying access points on primary roads as hazardous sites, observations of road user behavior at these sites have been carried out in order to establish behavioral and design factors associated with a hazardous outcome of interaction between motorcyclists and other road users. The data collected for this thesis ranges from accident records to on-site observational data including speed and behavior. The methods used are analysis of accident data behavioral observations on selected sites and advanced statistical modeling. The result show that Malaysian road accident statistics suffers from disproportional underreporting of severe injuries, hence any reliable road safety analysis only can be based on fatality records. Motorcycle fatalities are most frequent in rural locations (61%), half of them are on primary or arterial roads, and the majority of them are on straight road sections (66%). With help of a Motorcycle Safety Performance Function, which is a mathematical function that relates the expected crash frequency of a roadway element to the traffic volume and other characteristics of that element, it was estimated that an increase in motorcycle fatal accidents per kilometer is highly associated with an increase of access points per kilometer and the average volume of motorcycles.
An observational study carried out at such access points detected a hazardous right turning movement, i.e. the Opposite Indirect Right Turn. In this movement, which is mostly performed by motorcyclists, the vehicle makes a right turn into the opposite lane on the main road, and continues in the opposite direction before crossing the middle line into its desired lane. Eighteen to twenty six percent of right turning motorcyclists entering a primary road from an access point performed the Opposite Indirect Right Turn. The study also shows that motorcyclists entering the primary road from the access point were involved in serious traffic conflicts to the same extent as other vehicles. A serious traffic conflict is a breakdown of vehicle interaction that could lead to a crash. The advanced statistical analysis showed that the risk of motorcyclists being involved in a serious traffic conflict is 2 to 4 times more likely if they accept a shorter gap to a single approaching vehicle (time lag of less than 4 seconds) and in between two vehicles (time gap of less than 4 seconds) when entering the primary road from the access point. Also, behavioral variables, such as stopping at the stop line, as well as road environment factors, such as lane width influence the occurrence of a serious traffic conflict.
Overall, this thesis shows the importance of identifying motorcyclists’ behavior, as well as road environment attributes, in order to understand the road safety situation of motorcyclists. This study will also benefit researchers and practitioners, engineers and decision makers on the subject of improving motorcycle safety not only in Malaysia but also in other countries with similar situation.
More than 50% of road accident fatality victims in Malaysia are motorcyclists, numbering more than 4,000 fatalities per year. The aim of this thesis was to investigate motorcyclists’ road safety problems in general in Malaysia, and narrow down the focus to the most salient road infrastructure related risk factors. After identifying access points on primary roads as hazardous sites, observations of road user behavior at these sites have been carried out in order to establish behavioral and design factors associated with a hazardous outcome of interaction between motorcyclists and other road users. The data collected for this thesis ranges from accident records to on-site observational data including speed and behavior. The methods used are analysis of accident data behavioral observations on selected sites and advanced statistical modeling. The result show that Malaysian road accident statistics suffers from disproportional underreporting of severe injuries, hence any reliable road safety analysis only can be based on fatality records. Motorcycle fatalities are most frequent in rural locations (61%), half of them are on primary or arterial roads, and the majority of them are on straight road sections (66%). With help of a Motorcycle Safety Performance Function, which is a mathematical function that relates the expected crash frequency of a roadway element to the traffic volume and other characteristics of that element, it was estimated that an increase in motorcycle fatal accidents per kilometer is highly associated with an increase of access points per kilometer and the average volume of motorcycles.
An observational study carried out at such access points detected a hazardous right turning movement, i.e. the Opposite Indirect Right Turn. In this movement, which is mostly performed by motorcyclists, the vehicle makes a right turn into the opposite lane on the main road, and continues in the opposite direction before crossing the middle line into its desired lane. Eighteen to twenty six percent of right turning motorcyclists entering a primary road from an access point performed the Opposite Indirect Right Turn. The study also shows that motorcyclists entering the primary road from the access point were involved in serious traffic conflicts to the same extent as other vehicles. A serious traffic conflict is a breakdown of vehicle interaction that could lead to a crash. The advanced statistical analysis showed that the risk of motorcyclists being involved in a serious traffic conflict is 2 to 4 times more likely if they accept a shorter gap to a single approaching vehicle (time lag of less than 4 seconds) and in between two vehicles (time gap of less than 4 seconds) when entering the primary road from the access point. Also, behavioral variables, such as stopping at the stop line, as well as road environment factors, such as lane width influence the occurrence of a serious traffic conflict.
Overall, this thesis shows the importance of identifying motorcyclists’ behavior, as well as road environment attributes, in order to understand the road safety situation of motorcyclists. This study will also benefit researchers and practitioners, engineers and decision makers on the subject of improving motorcycle safety not only in Malaysia but also in other countries with similar situation.
Avdelning/ar
Publiceringsår
2014
Språk
Engelska
Publikation/Tidskrift/Serie
Bulletin
Volym
290
Fulltext
Dokumenttyp
Doktorsavhandling
Förlag
Lund University
Ämne
- Infrastructure Engineering
Nyckelord
- access point
- primary road
- motorcyclists’ behavior
- Safety Performance function
- Motorcycle accident fatality
Status
Published
Handledare
ISBN/ISSN/Övrigt
- ISSN: 1653-1930
Försvarsdatum
22 maj 2014
Försvarstid
10:00
Försvarsplats
In auditorium E:1406, E-building, John Ericssons väg 1, Lund University Faculty of Engineering
Opponent
- Stijn Daniels