In 2001, National Transport Insurance Ltd (NTI) volunteered to forward heavy truck crash data to the Australian Transport Safety Bureau (ATSB) for analysis. This report looks at NTI truck crash claims for 1998 to 2002. In an attempt to capture crashes predominantly involving the long-distance truck fleet, the analysis was confined to incidents where trucks were at least 500 kilometres outward distance from base. To eliminate the straggle of crashes at very long distances from base, a cut-off point of 1499 kilometres outward distance from base was used.
The NTI data show that approximately:
- 88 per cent of NTI crashes occurred within 500 kilometres from base;
- 2 per cent occurred at distances of 1500 kilometres or more; and
- the remaining 10 per cent of crashes, of which nearly three-quarters were on an outward leg of a trip, were in the 500-1499 kilometres from base range.
Knowing the outward distance from base means that it is possible to roughly estimate the number of hours a truck had been on the road prior to the crash.
The NTI data did not include details of injuries - fatal or otherwise - sustained by anyone involved in the crashes; therefore, for the purposes of this paper, any crash that incurred a claim of $10 000 or more has been defined by ATSB as a major crash.
Over the 1998 to 2002 period:
- 38 per cent of NTI truck crashes in the 500-1499 kilometres outward distance from base range fell into the major crash category.
- Peaks in major crashes occurred at 900-999 and 1100-1199 kilometres outward distances. For all crashes (ie. major plus non-major crashes), peaks occurred at 900-999 and 1200-1299 kilometres outward distances, although in 2002 a shift had begun to manifest whereby crashes had declined at 900-999 kilometres and increased at 1100-1199 kilometres outward distance from base.
- The majority of crashes occurred during the day.
- 60 per cent of major crashes occurred during the day, and
- 70 per cent of all crashes occurred during the day.
For both major and all crashes, the greatest proportion of crashes occurred during the morning quarter - 6am to noon - of a full day. The hours between 5am-7am appear to have been a particularly critical time for major truck crashes in the most recent two years of the data set, although there was also a noticeable peak at 10am in 2002, and at 7pm in 2001. Over the most recent three years, a shift in the time sector of major crashes was apparent.
- major crashes in the noon-6pm sector had halved (falling from 20 to 10 crashes), and
- major crashes between midnight-6am had almost doubled (increasing from 11 to 20 crashes).
For major crashes, the dominant crash types were:
- ‘Ran off road’ (28 per cent), followed by
- ‘Hit third party in rear’ (12 per cent).
The two dominant crash types were reversed in all crashes, whereby:
- Hit third party in rear’ was the most predominant (22 per cent), followed by
- ‘Ran off road’ (14 per cent).
The group of crash types gathered together to loosely form the possible fatigue-or-speed related crashes (‘Ran off road’, ‘Failed to take bend’, ‘Rolled due to driver error’, ‘Driver fatigue’, ‘Head on collision’ and ‘Excessive speed’) accounted for:
- 52 per cent of major crashes; and
- 27 per cent of all crashes.
Most rear end or failure to give way collisions (82 per cent) were not major crashes and most occurred between 6am-6pm (83 per cent). Similarly, the majority of turning, merging and lane changing incidents (87 per cent) were not major crashes and most occurred between 6am-6pm (77 per cent). Approximately half the collisions with animals or trains, jackknife or tyre failure incidents were major crashes and almost half occurred between 6am-6pm. Most of the crashes involving animals occurred overnight – particularly between 6pm-midnight. Cattle were involved in well over half the major crashes with animals.
Looking at the possible fatigue-or-speed related crashes:
- over three-quarters of these were categorised as major crashes;
- nearly 60 per cent of all possible fatigue-or-speed related crashes occurred between 6am-6pm, and over half of these crashes were ‘Ran off road’ crash type; and
- the most critical time for possible fatigue-or-speed crashes appeared to be between 3am-8am.
Interestingly, while the number of all crashes in the 500-1499 kilometres outward distance range decreased substantially in 2001, the possible fatigue-or-speed related crashes peaked in that year. That is, during 2001 the possible fatigue-or-speed related crashes, on average, increased slightly while other crash types reduced in volume. Possible fatigue-or-speed related crashes were more predominant during the months of August to December with a noticeable peak in August.
The majority of all crashes in the individual freight carrier categories occurred between noon-6pm, the only notable exception being ‘Tipping’ crashes, which occurred predominantly between 6am-noon. However, if looking at only major crashes, the majority of crashes for most of the different freight carrier categories occurred in the 6am-noon sector.
It would appear that in truck crashes where driver fatigue was assessed as being implicated, the later in the day that the trip began, the shorter was the distance covered prior to the crash.
Type: Research and Analysis Report
Topics: Crash data, Heavy vehicle, Statistics
Publication Date: 01/01/04