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1.3 Research Questions

The overarching research question of this research is: what are the factors contributing to
heavy-vehicle crashes in Victoria, Australia? To answer this question, three specific research

questions are generated:

1. Are there any differences in the factors contributing to single heavy-vehicle crashes at

intersections and mid-blocks?

2. What are the socioeconomic characteristics of neighbourhoods where road users live and
where crashes occur have a significant influence on road-user injury severity in crashes

involving heavy vehicles?

3. What are the factors contributing to injury severity in angle collisions involving heavy

vehicles?

1.4 Scope of Thesis

This thesis reports the results of three studies to achieve the objectives of the research and
answer the research questions:

Study one examines the differences in the factors contributing to crashes at intersections and

mid-blocks. It applies fixed and random parameter logistic regression models to all police-

reported collisions in the Melbourne metropolitan area in Victoria, Australia. In addition to
the data on collisions, road users, vehicles and environmental characteristics, information on

traffic volume and road features (e.g. road division marking) were extracted from the

Australian Urban Research Infrastructure Network Portal (AURIN) for the study.

Study two examines the socioeconomic characteristics of neighbourhoods where the road
users live and where the crashes occur, which may have a significant influence on road-user

injury severity in crashes involving heavy vehicles. The data used in the study include all
police-reported collisions in Victoria, Australia, from 2006 to 2016, information on traffic

volumes and road features from AURIN, and socioeconomic data at the postcode level from

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