11.0 IMPACT OF LAND-USE CHANGE ON DISTRICT ROADS
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Key points
- Eighty-two percent of the District's roads (excluding State Highways) are unsealed. Most have a carriageway of less than 5 metres, and would require extensive upgrading for use by logging traffic.
- The increase in volume of heavy traffic on rural roads leads to increased noise and dust and a perceived loss of safety.
- Existing funding mechanisms result in an inefficient and inequitable spread of the costs of road upgrading for logging traffic through time.
- Communication that facilitates early planning for log transport is critical.
- Alternatives to road for log transport generally require large loads travelling long distances.
11.1 Introduction
Responsibility for roads in rural areas is shared between Transit New
Zealand (State Highways) and the local authorities. Wairoa District Councillors have
expressed concern over the impact of logging traffic on the ability of the Council to
maintain rural roads at their present standard from rates revenue. This chapter explores
the issues from the basis of existing knowledge and recommends areas for future action.
Data in this chapter has been provided by the Wairoa District Council.
11.2 Wairoa District road network
The District roading infrastructure, excluding State Highways, is
approximately 863 km, of which 78% is unsealed (Table 11.1).
11.3 Roading expenditure and funding
Current total District roading expenditure is budgeted at $4.5 million
per annum (32% of expenditure), against which there is a 57% Transit New Zealand subsidy
of approximately $2.6 million. Net expenditure is therefore $1.9 million, which is at
present approximately 38% of the rating base.
A significant proportion (80%) of the roading programme attracts Transit
New Zealand subsidy as regular maintenance. The current Finance Assistance Rate (FAR) is
63%, but this is expected to rise to 65%. Capital construction items (e.g. seal
extensions, bridge or road reconstruction) also have access to subsidy funding but are
required to meet a specified benefit:cost ratio based on detailed analysis of current use,
condition and maintenance costs. The Council undertakes some seal extensions without
subsidy for public health reasons and to reduce maintenance costs. In general, however, it
is dependent on building a case to meet the benefit:cost criteria to fund major
reconstruction, resealing, shape correction and strengthening or seal extensions. In
recent years this has been difficult given limited capital funds in the pool and heavy
demand from urban centres.
Table 11.1 Wairoa District road network
| Responsibility | Road type | Road group 1 | Total road length (km) | |
| Sealed | Unsealed | |||
| Transit NZ (State Highways) | SH 2 | 108 | ||
| SH 38 | 64 | |||
| Subtotal | 172 | |||
| Wairoa District Council (District Roads) | Urban (50 km/h limit) | T1 | 27.5 | |
| T2 | 25.3 | |||
| T3 | 6.5 | |||
| U1 | 2.1 | |||
| U2 | 0.1 | |||
| Rural (not subject to 50 km/h limit) | T1 | 14.1 | ||
| T2 | 43.2 | |||
| T3 | 68.7 | |||
| U1 | 431.1 | |||
| U2 | 152.3 | |||
| U3 | 92.1 | |||
| Subtotal | 185.3 | 677.7 | ||
1 As defined by the Road Assessment & Maintenance Management (RAMM)
system, Transit New Zealand 1993: U = unsealed; T = thin-surfaced, flexible; 1 = less than
100 vehicles/day; 2 = 100-500 vehicles/day; 3 = 500-2000 vehicles/day.
The major rationale for sealing or reconstructing roads to handle logging traffic is to
reduce expected maintenance costs, particularly on steep gradients. Developing a funding
case on this basis is dependent on:
- accurate and detailed maintenance cost data; and
- accurate forecasts of future use, especially by heavy traffic.
11.4 Road design and the impacts of logging traffic
Most of the non-arterial rural roads in Wairoa District have a carriageway of five
metres or less, and are unsealed. This is suitable for average annual daily traffic loads
of less than 30 vehicles, or average annual heavy vehicle daily loads of less than 10 (NZ
Counties Association 1985) but is generally too narrow for regular use by heavy commercial
vehicles. Two logging trucks, for example, would have difficulties passing each other on a
carriageway of this width. Six metres has been promoted as a more adequate width for roads
carrying up to 30 heavy vehicles per day (Forestry Road Funding Taskforce 1993). Current
axle limits are designed to allow different vehicle configurations to reach the maximum
gross vehicle weight limit (44 tonnes) without being limited by specific axle group
constraints.
The increased use of a particular road by heavy commercial vehicles, particularly at
high intensities as with logging trucks, substantially increases wear (Clough &
Meister 1987). This results either in earlier road failure than otherwise expected where
roads have not been constructed for heavy traffic or in an increase in maintenance effort
commensurate with the increase in heavy traffic use. In either case road expenditure
increases, either immediately through increased maintenance or in the short to medium-term
with major reconstruction or repair costs. Even where maintenance is suitably increased,
road life is likely to be shortened, particularly on sealed surfaces, and reconstruction
costs brought forward.
Averaged over a period of 28 years, forestry generates substantially higher numbers of
heavy vehicle trips per 1000 ha in use than does pastoral farming, and is exceeded only by
dairy farming (Clough & Meister 1987). The physical impact is compounded by the
concentration of peak flows into the few years of harvesting (Clough & Meister 1987).
It is also recognised that forestry transport has a significant potential for illegal
overweight loads (Forestry Road Funding Taskforce 1993).
In addition to potential road deterioration, there are important social issues. These
include the rapid increase in the volume of heavy traffic on rural feeder roads used
predominantly by farm families, increases in noise and dust levels, and the perception of
reduced road safety as a result of increased heavy traffic use although there is no data
to suggest that safety levels deteriorate once forestry traffic reaches a certain level
(Forestry Road Funding Taskforce 1993). The likelihood of reduced road safety is greatly
increased, however, if roads are allowed to deteriorate significantly before funds can be
raised to upgrade them.
11.5 Funding road upgrading for logging traffic
Road funding is a partnership between the local Council funded through rates and
Transit New Zealand which distributes grants in accordance with a benefit cost evaluation
mechanism. The new procedure developed by Transit to assess funding requests largely
alleviates historical concerns that it was difficult for a Council to build a case for
extra expenditure on a particular road before logging commences (Clough & Meister
1987).
There is no guarantee, however, that the amount of grant made to a particular Council bears any direct relation to the funds contributed by road users in that District through road user charges or to the damage that road users in that District generate. These issues are determined by the adequacy of the funding of the Road Transport Fund at a national level.
A concern that continues to be expressed by the farming community, however, is the
likelihood of increases in rates to maintain roads at their present standard when logging
commences from forest blocks. This would be the result of an increase in the total level
of roading expenditure making increased demands on rates as well as additional Transit
funding. An increase in general rates to cover these costs would be perceived as an
effective subsidy of forest growers by other land-users. This issue is currently being
addressed by a national taskforce looking at the capital funding of road construction and
upgrading.
Rural rating in Wairoa District is based on land value and is at a flat rate. Rate
contributions from newly planted forests on pasture may actually decline slightly. This is
because a change from pasture to trees will lower the land value assessed by Valuation New
Zealand because of the potential costs that would be incurred in returning forest land to
pasture. On the other hand, in a market where forest buyers are pushing land values up,
gross rate revenue potentially increases significantly. Similarly, if it is mostly
scrub-covered land that is being converted to forestry, land value and rates payable will
rise.
In the past, forest companies have expressed concern at attempts by local authorities
to impose additional revenue collection measures such as differential rating or special
grants, rates or bonds on forest owners. Current ratepayers are also concerned at the
additional costs of road maintenance and improvement and the subsequent increase in rates
that log transport is likely to impose. Local Bodies are also concerned at the difficulty
under existing funding mechanisms in spreading road improvements over a number of years
before harvesting commences (Forestry Road Funding Taskforce 1993).
Differential rating is a difficult policy instrument to use for roading. Establishing
rate levels on the basis of the use of services leads to complicated administration and
difficulties in assessing relative use. For example, farms in Wairoa District with
forestry plantings would conceivably also have to be rated at a higher level on planted
land under a differential rating system. In any case, there is currently no accepted
method of calculating the extraordinary damage resulting from a single road user as
distinguished from damage caused by other road users.
Further, there are procedural and legal difficulties in establishing differential
rating systems under existing legislation, as evidenced by challenges to such systems in
Mackenzie District, Waimate District, Masterton District and Manakau City (Forestry Road
Funding Taskforce 1993). These decisions suggest that Councils must take into account the
level of services received and that the value of a differential rate must bear some
reasonable relationship to the reason for the differential.
11.6 Planning road upgrading for logging traffic
A number of rural feeder roads will require significant upgrading for harvest use over
the next 10-15 years. Adequate provision for logging traffic in terms of planning, funding
and construction can generally be made if there is good communication between the Council,
Transit New Zealand and forest companies. Councils are looking for three to five years
advance warning of harvest sources, volumes, destinations and likely routes in general
terms. Most large forest companies can provide this information, although smaller growers
are likely to give less warning of an intent to fell because they tend to sell on the spot
market.
Where adequate communication, planning and preparation has not occurred, Councils have
used weight restrictions and road closures to prevent excessive damage. Such action is in
nobody's interest, given that it is usually initiated only after major damage has already
occurred and significant repair costs generated, and that it engenders major disruptions
to harvesting operations.
Formal notification systems such as forestry development notices can go some way
towards providing this information but are inappropriate for specifics regarding expected
harvest dates, tonnages and destinations, given they are prepared 25-30 years before
harvesting.
Detailed analysis of specific road sections, expected traffic loads and estimated
upgrading costs for the Wairoa District are outside the scope of this report. Given the
forecast increases in wood flow over the coming five years, however, this issue requires
addressing in the near future.
11.7 The impact of planned approaches to forest development and logging
The most efficient forestry structure from a roading expenditure perspective is large,
concentrated forestry blocks. This maximises heavy traffic use over relatively short
defined sections of public road or over private roads linked to processing plants. A
scattered forestry resource in small blocks, as generated by random sales or potentially
generated by 'planned' approaches based on land quality or some other measure, is
inefficient and expensive in roading use, upgrading and maintenance.
Pavement wear is closely related to the moisture level of both the pavement itself and
the underlying natural soil. Under moist soil conditions bearing capacity is lower,
deformation in the pavement surface increases and permanent damage occurs. Repetitive
heavy traffic passes over pavement also prevent dissipation of water pressure weakening
the surface and increasing permanent deformation. It therefore follows that if heavy,
repetitive loads on weaker surfaces, e.g. from isolated forests served by rural roads, can
be restricted to summer months, road maintenance costs will be reduced.
11.8 Alternative Log Transport Systems
Private roads and rail lines transported 33% of logs in New Zealand in 1993 and
continue to offer an alternative to use of public facilities (Forestry Road Funding
Taskforce 1993). Benefits to forest owners are generated by savings in road user charges
and in having no weight restrictions. The viability of these systems is dependent on the
volume carted, the type of vehicle that can operate in the terrain and on a direct link
between forest and mill.
The use of rail as an alternative log cartage system is only likely to be viable once
large harvest volumes travelling a considerable distance are available. For example, Juken
Nissho are currently making use of rail for log transport to their Masterton mill but are
unlikely to do so to a local or Gisborne mill. Rail has, however, recaptured some of the
traffic it lost to road with the 1980 deregulation of transport limits, and is likely to
continue to do so where it is economically more attractive, e.g. through the introduction
of 50+ tonne wagons (Forestry Road Funding Taskforce 1993).
Changes to the industrial structure of port operations have also meant that barging may
become a viable alternative transport option in some locations. Barging operations have
taken place in Auckland, Northland and in the Marlborough Sounds.
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Contact for Enquiries
Rural Affairs Coordinator
Sector Performance Policy
MAF Policy
Ministry of Agriculture and Forestry
PO Box 2526
Wellington
NEW ZEALAND
Phone: +64 4 894 0675
Fax: +64 4 4 894 0745
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