Page 100 - tmp_Neat

Chapter 6 Conclusions and Future Research

6.1 Conclusions

This research investigated heavy vehicle crashes and injury severity. The safety of heavy

vehicles has drawn considerable attention from government agencies and the general public.

In general, heavy vehicles have many unique operating characteristics, such as poor
acceleration and stopping capabilities, high rigidity, great mass and length, and these factors

may contribute in part to their over-representation in traffic fatalities and serious injuries.
Based on the existing literature, several limitations in existing heavy vehicle crash studies

were identified. First, no research has been done on factors contributing to single heavy-
vehicle collisions at crash locations. Second, no study has investigated the effects of

neighbourhood socioeconomic characteristics on traffic crashes involving heavy vehicles.

Finally, no research has been done on factors contributing to heavy-vehicle angle crashes. To
address the identified limitations in the literature on heavy-vehicle collisions, this study used

statistical models to develop binary logit, scobit, multinomial logit and random parameter
(mixed logit) models. The key findings of each study are summarized in the following sub-

sections.

6.1.1 Single heavy-vehicle collisions at crash locations

In the first study (Chapter 3), a binary logit model was developed to examine factors

contributing to single-vehicle crashes involving heavy vehicles at intersections and mid-block
in the Melbourne metropolitan area. This research has provided an understanding of

characteristics influencing single heavy-vehicle crashes at intersections and mid-block. Based
on the binary model estimation, differences were identified in single heavy-vehicle crashes at

intersections and midblocks. These differences in the factors contributing to single heavy-
vehicle crashes at intersections and mid-block are summarised below:

 Crashes at intersections are more likely to be associated with turning vehicle
movements prior to the crash (turning right and turning left), crashes on

freeways or highways and main roads, and involving angle and overturn crashes.

80