41001 � Submission
� Vehicle Dimension and Mass
Summary of submission
- CAN generally support the red draft.
- CAN propose that a minimum certified SRT performance of 0.45 g apply to all vehicles first registered in New Zealand 12 months from the date the rule comes into force, as opposed to the red draft proposal of 0.40 g.
- CAN oppose a possible increase in heavy-vehicle limits, as it is earmarked for the release of the yellow draft of this rule.
Introduction
CAN (Cycling Advocate�s Network) agree with the performance-based approach of trying to reduce the truck crash rate. As representatives of a road user group (cyclists) as well as from an altruistic stance, we strongly support the aim of making roads safer to use.
static rollover threshold
We would like to comment on the performance measure that has been shown to be a strong indicator of crash risk for heavy vehicles � the �static rollover threshold� (SRT).
We are not in the position to question the SRT value of 0.35 that you propose for immediate implementation. We do feel, however, and believe that we can justify that the SRT value of 0.40, to be met 12 months later, is not high enough.
The graph shown in the red draft of the rule, reproduced from �Report No: UMTRI-85-53. University of Michigan Transportation Research Institute 1986�, shows a sharply declining percentage of single vehicle crashes with increasing rollover threshold. This suggests that the rollover threshold should be set as high as possible (without making the implementation too expensive, of course).
Elsewhere in the red draft is stated �Load height limitations are only a second-best measure compared to the alternative of designing logging vehicles to achieve good stability performance levels in their applications. Such an approach could conceivably produce vehicles with as high a productivity as that achievable under current axle limits, and which do not result in higher manufacturing or operating costs in comparison to the vehicles currently being used. Costs would essentially be those of design, which would be one-off in nature. Initial analysis suggests that well-designed logging vehicles could achieve an SRT performance level of 0.45g, with no loss of carrying capacity.�
In order to maximise road safety, CAN would like to see an SRT level as high as possible being implemented. If it is possible to design new vehicles with an SRT value of 0.45 without loss of carrying capacity, then this higher value should be chosen over the value of 0.40 as stated in the red draft.� If more research needs to be done to determine an SRT value that can be achieved with good design, than the implementation of the future SRT value should be deferred.
heavy-vehicle limits
It is mentioned in the red draft that �Transit New Zealand is currently reviewing possible increases in heavy-vehicle limits, and the LTSA proposes to consider including any proposal arising from this review that is technically sound and has a suitable social benefit/cost ratio in the public consultation (yellow) phase of this rule.�
CAN is concerned about possible negative impacts that might result from an increase in heavy-vehicle limits.� A potential consequence is the accelerated deterioration of carriageways, which may result in an increased number of potholes and subsequently metal on the road, rutting and other negative consequences on the road surface.� The possible impacts on cyclists due to loose metal and potholes are:
- Inconvenience.
- Damage to tyres and rims.
- Crash risks due to loss of control.
- Crash risk with possibly serious consequences when cyclists are inattentive and suddenly swerve into the path of motorised traffic while avoiding loose metal or potholes.
CAN wish to be kept informed about the possible increase in the heavy-vehicle limits and will make a more detailed submission on this aspect should it be included in the yellow draft of the rule.
Axel Wilke for CAN