Draft regulation Impact Statement for Underrun Protection a draft statement inviting discussion and comments from parties affected by the proposed heavy commercial vehicle safety initiative January 2007 Report Documentation Page
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ProblemNature of the ProblemWhen a heavy commercial vehicle and a passenger car, or vulnerable road user such as a motorcycle, bicycle or pedestrian collide, the results are nearly always more serious for the passenger car occupants or the vulnerable road user than for the heavy commercial vehicle occupants. This is especially true if the front of a smaller vehicle slides under the front or the rear end of a heavy commercial vehicle as happens in a heavy vehicle underrun crash. The high risk of injury to other vehicle occupants from underrun crashes is a result of the lack of compatibility between the colliding vehicles. Vehicle mass, stiffness and geometry affect compatibility. A smaller vehicle under-rides a heavy commercial vehicle to the extent that the heavy commercial vehicle’s front or rear extremity enters the occupant compartment or space of the smaller vehicle. Such occupant space intrusion frequently leads to serious injuries or fatalities. When an underrun crash between vehicles occurs, there are two noticeable outcomes. The first, as described above, is the trauma from the exposure of the smaller vehicle’s occupants to impacts with the interior compartment of their vehicle, occupant protection measures in the smaller vehicle being unlikely to engage. The second is the likelihood of further collisions arising from the loss of control of the heavy vehicle. This follows from damage to the steering or braking components of the heavy vehicle by the smaller vehicle. During the period 1990 to 1999,i an average of about 50 people were killed annually in Australia in underrun crashes. Around 40 of these fatalities were passenger car occupants, 5 were motorcycle riders and 5 were bicyclists. (ATSB 2004c). The driver of the heavy commercial vehicle was rarely killed or injured. The number of pedestrians is difficult to estimate as crash databases do not specifically codify pedestrian injury arising from collisions. A very rough estimate would place fatalities of pedestrians in underrun collisions at 10 to 15 persons annuallyii. Figure 1 shows that there has been a gradual decline in underrun collisions for both articulated truck-car underrun collisions and rigid truck-car collisions from a high of 86 fatalities in 1990 to a low of 45 fatalities in 1999. The decline could be attributed to a higher intensity in enforcement by state transport agencies, improvements to roadways and heavy vehicle accreditation programs (operated by private and public sector agencies), which target fatigue, mass limits and vehicle roadworthiness. However, it could be predicted that there will be an increase in the future, due to an expected doubling of the freight transport task by 2020. Figure 1: Heavy commercial vehicle underrun fatalities between 1990-99 by type of heavy truck and passenger car collision  
Source: FCD 1990-99 Front underrun collisions involving heavy commercial vehicles contribute to around 70-75 per cent of underrun fatalities. In the typical passenger car fatal offset front crash there are high levels of intrusion into the occupant space. European research studies show that in 75 per cent of the cases, the usual occupant protection features built into cars such as seatbelts, airbags, energy absorbing steering columns and crush zones are not engaged. Side underrun collisions involving heavy commercial vehicles contribute to around 15 per cent of fatalities. The collisions often occur at night but also during the day. In Japan, Europe and some developing economies, because of the immense amount of bicycle and motorcycle traffic, heavy rigid and articulated commercial vehicles must have side Underrun Protection (UP). This type of UP is targeted at protecting vulnerable road users or near parallel collisions with passenger vehicles (an typical example of this is on 4-lane highway where a long heavy commercial vehicle changes lanes while there is a passenger vehicle moving parallel within its blind spot). However, it does not have the structural strength to engage the occupant protection systems of vehicles in a typical “T-bone” side underrun collision. Rear underrun collisions involving heavy commercial vehicles contribute to around 10 per cent of underrun fatalities. These are a particularly severe crash type for a passenger car because the floor structure of most heavy vehicles is above the bonnet height of the car. The car can run under this structure which may in turn penetrate through the car’s ‘A’ pillars and into the occupant compartment. Again, the usual occupant protection features built into cars such as seatbelts, airbags, energy absorbing steering columns and crush zones are bypassed during these collisions. The difference in traffic patterns around the world means that the value of fitting UP in Australia can not be assumed through the actions of other countries. However, it would be justifiable to draw from world research on the effectiveness of UP for particular road user types, and then combine this with Australian crash statistics. In Australia, insufficient separation between traffic streams in rural areas has been a significant cause for heavy vehicle underruns. Table 2 shows that in case of articulated truck crashes involving underrun, passenger car occupant fatalities are higher in rural areas than urban areas, while for rigid trucks the fatalities are closer to being equally shared. Table 2: Percentage of underrun fatalities by urban/rural location
Source: FCD 1990-1999 Growth in freight transport task: Fatalities from underrun crashes do not represent a large part of the crash population and are about 3-5 per cent of the total from all types of road user fatalities. However, with the total freight transport task likely to double in the next 20 years, the role of articulated heavy commercial vehicles is likely to expand, as shown in Figure 2. Rigid truck movements are likely to decline gradually, which will have a negative impact on sales of rigid trucks from around 2010. Figure 2: Vehicle kilometres travelled by commercial vehicles: actual and projected 
Source: BTRE Freight Measurement and Modelling Directory: barreirastecnicas -> pontofocal -> textos -> regulamentos pontofocal -> Ind- 2001 0382 nl- en regulamentos -> Kenya standard ks 06-77: 1978 ics 13. 340 Download 5.27 Mb. Share with your friends:
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