23890 version 1
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Demonstrate knowledge of overweight and overdimension vehicle
dynamics for safe driving
Level
4
Credits
6
Purpose
This unit standard is for drivers of vehicles with overweight and
overdimension loads.
People credited with this unit standard are able to: describe the swept path of
a specified loaded vehicle; describe how a load’s position on the vehicle
trailer(s) affects stability; describe the preparation and techniques for
maintaining load stability; describe the effects of weather conditions in terms
of transporting a heavy haulage load; and describe the driving techniques for
travelling downhill when transporting a heavy haulage load.
Subfield
Commercial Road Transport
Domain
Heavy Haulage
Status
Registered
Status date
21 September 2007
Date version published
21 September 2007
Planned review date
31 December 2012
Entry information
Recommended: Unit 18079, Demonstrate knowledge of
heavy combination vehicle dynamics and handling for
safe driving, or demonstrate equivalent knowledge and
skills.
Accreditation
Evaluation of documentation and visit by NZQA and
industry.
Standard setting body (SSB)
NZ Motor Industry Training Organisation (Incorporated)
Accreditation and Moderation Action Plan (AMAP) reference
0092
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
 New Zealand Qualifications Authority 2016
23890 version 1
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Special notes
1
Legal requirements to be complied with include:
Land Transport Act 1998;
Land Transport Rule: Heavy Vehicles 2004;
Land Transport Rule: Heavy-vehicle Brakes 2006;
Land Transport Rule: Vehicle Dimensions and Mass 2002;
Traffic Regulations 1976.
2
Any new, amended, or replacement Acts, regulations, Rules, standards, codes of
practice, Land Transport New Zealand or Transit New Zealand requirements or
conditions affecting the outcome of this unit standard will take precedence for
assessment purposes, pending review of this unit standard.
3
References
The Official New Zealand Truck Loading Code – Code of Practice for the Safety of
Loads on Heavy Vehicles (current edition), available from booksellers;
The Transit New Zealand Overweight Permit Manual SM070 1995, available at the
Transit New Zealand website www.transit.govt.nz/technical/manuals.jsp.
4
Definitions
Organisational requirements include any legal requirements, standards, codes of
practice, organisational and/or site requirements, industry best practice, and
manufacturers’ instructions. These must be available to candidates, providers, and
assessors;
The Rule is Land Transport Rule: Vehicle Dimensions and Mass 2002;
Road furniture is pedestrian refuges, power poles, stop and give-way signs, street
signs, telephone poles, threshold signs, traffic control signs such as traffic lights, and
any other items that are positioned on or near a road and that need to be considered
by an operator in relation to an overdimension load vehicle fitting the route;
Road geometrics include but are not limited to – width, camber, crossfall, gradient,
surface, horizontal and vertical curvature;
Swept path means the maximum road width required by a vehicle when it negotiates
a turn;
A vehicle is a combination vehicle.
Elements and performance criteria
Element 1
Describe the swept path of a specified loaded vehicle.
Performance criteria
1.1
The description includes the amount of road space required to pass through,
the trailer swing arc, and load tail swing outwards.
1.2
The description identifies the boundaries of available roadway for both vehicle
and load.
1.3
The description includes the amount of roadway required between road
furniture and structures to allow the load to safely pass.
 New Zealand Qualifications Authority 2016
23890 version 1
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Element 2
Describe how a load’s position on the vehicle trailer(s) affects stability.
Performance criteria
2.1
The description includes an explanation of the stability triangle in relation to load
positioning.
2.2
The description includes the effect of load position on vehicle traction.
2.3
The description includes the effect of load position on jack-knifing.
2.4
The description includes the effect of the alignment of the load divider and the
trailer on stability.
Element 3
Describe preparation and techniques for maintaining load stability.
Performance criteria
3.1
The description includes completing a route survey and temporary removal of
road furniture in accordance with the Rule and organisational requirements.
3.2
The description includes driving techniques to maintain load stability in relation
to road geometrics and permanent road fixtures such as kerbs and traffic
islands.
3.3
The description includes trailer adaptation and steerable axle positioning to
maintain load stability.
3.4
The description includes the use of braking systems to maintain load stability.
Element 4
Describe the effects of weather conditions in terms of transporting a heavy haulage load.
Performance criteria
4.1
The description includes the need to monitor weather forecasts and weather
conditions en route.
4.2
The description includes techniques to counter the effect of tail winds on vehicle
engine cooling.
4.3
The description includes techniques to counter the effect of rain, snow, and fog
on visibility and/or load stability.
4.4
The description covers situations where the vehicle must be stopped en route
because of weather conditions.
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23890 version 1
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4.5
The description covers situations where the load must be protected because of
weather conditions.
4.6
The description includes techniques to prevent damage to a sealed road
surface in bleeding tar conditions.
4.7
The description includes techniques to counter the effect of ice on the road
surface.
Element 5
Describe driving techniques for travelling downhill when transporting a heavy haulage
load.
Performance criteria
5.1
The description includes speed selection in relation to the gradient and gradient
length, load mass and size, load position, and load stability triangle.
5.2
The description includes gear selection, engine braking, use of a fitted retarder,
use of service brakes, and ancillary braking systems.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP also includes useful information about special requirements for organisations
wishing to develop education and training programmes, such as minimum qualifications for
tutors and assessors, and special resource requirements.
Comments on this unit standard
Please contact NZ Motor Industry Training Organisation (Incorporated) info@mito.org.nz if
you wish to suggest changes to the content of this unit standard.
 New Zealand Qualifications Authority 2016