4 - Haul Route Response - B14101TL001

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25 May, 2015                               -2-
Our File Ref: B14101TL001
Contact: Steve Williams



We have prepared an updated set of Concept Drawings and attach these are for
inclusion in the approval package and Infrastructure Agreement. The relevant plans are
as noted below.

•      B14101-SK-004 (Rev B)
•      B14101-SK-005 (Rev C)
•      B14101-SK-006 (Rev A)
•      B14101-SK-007 (Rev A)

In preparing these final drawings we have, on behalf of our client, undertaken significant
additional work and the including the following items. Note that the concepts have been
undertaken to a level of detail more than would typically be provided at DA Stage,
however remain subject to further detailed design:

•      We have altered the general concept design to provide a 6.0m wide sealed
       pavement as discussed and agreed during our meeting with Council;
•      This is increased to a minimum of 7.0m at the major bend in the road at around
       chainage 1100m through 1200m (Ch0 starting at Old Ceylon Road) as discussed
       and agreed with Council;
•      Table drains have been provided in accordance with the Council required
       maximum grades of 1m in 4m;
•      Additional survey has been collected in the vicinity of the bend mentioned above
       to allow the concept to tie in with the existing ground levels;
•      We have commissioned a detailed Geotechnical Investigation which has
       assessed both the existing pavement composition (including underlying
       pavement strength) and also undertaken a slope stability assessment for the
       aforementioned curve widening;
•      The concept design has taken into consideration the findings of the geotechnical
       investigations in relation to the slope design concept; and
•      We have had our Senior Ecologist undertake an initial assessment of the corridor
       with a particular focus on the aforementioned curve widening area.

We believe that the Concept Design as represented in these plans adequately and
comprehensively addresses the issues raised by Council and should provide Council
with the comfort that their preferred road upgrade is able to be built. The plans provided
show property boundaries and overhead power lines in the critical location.

We note that it is accepted that the road upgrade would require provision of appropriate
road signage and guide posts generally as outlined in the Hayes Traffic Engineering
report submitted as part of the initial application and could be conditioned accordingly.
This will include additional hazard markers adjacent to existing cross drainage
structures. The provision of signage and line-marking would be in accordance with
relevant Council standards and the MUTCD where relevant.

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25 May, 2015                                 -3-
Our File Ref: B14101TL001
Contact: Steve Williams



Pavement Design Concept
We note that the Concept Design as now represented in the plans has been based on
Councils requirement to provide a pavement design in accordance with the Councils
Planning Scheme Policy 5 Section 3.19 with the minimum overall pavement depth of
200mm.

We note that initial plans included a pavement design that had been based on detailed
analysis undertaken from first principles. As part of the pavement design process we
had initially adopted the following key parameters:
•       Design Life                          -      20 year
•       Design Vehicle Loadings (ESA’s)      -      7.69 x 104
•       Design Subgrade CBR                  -      15%

The result of our detailed CIRCLY analysis and design resulted in an overall pavement
depth of 160mm. We attach the previous detailed CIRCLY analysis for reference.

The design vehicle loading were calculated based on the existing vehicle movements
along Top Forestry Road (based on count data collected as part of our assessment) with
the “worst case” design traffic added to this existing background traffic.

Furthermore, we note that at the time of completing the pavement design we did not
have access to the results of the detailed geotechnical assessment. Subsequently the
Geotechnical investigation has been undertaken and found a subgrade CBR of 11 for
the underlying subgrade material below the existing pavement. We note that the intent
of the design concept is to effectively “build up” the road and make use of the existing
pavement. The geotechnical report has identified that taking this approach and based
on limited excavation of the existing road formation the design CBR could be as high as
CBR20.

As previously noted however, in the interests of working with Council to achieve their
preferred outcome, we note that that our client has accepted the requirement to provide
a minimum pavement depth for rural roads as outlined in PSP5 of 200mm. We note that
we have also assumed a bitumen seal along the length of Top Forestry Road. We have
done a further detailed analysis of the pavement based on the Council pavement depth
requirements with subgrade CBR values of 10 and 12 to demonstrate the adequacy of
the pavement design and attach these for reference.


Ecology Impacts
This is addressed under a separate letter appended to this correspondence. The
primary finding is that while the upgrade will necessitate the removal of some large trees
this is not expected to result in any substantial loss of habitat. It is noted that following
direct discussions with Council Manager Planning & Environment it was clear that a full
and comprehensive “tree identification” survey was not required at this point and Council
was after a more general assessment to identify any potentially significant issues that
may arise that would be a major barrier to any upgrade of the corridor.

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25 May, 2015                                -4-
Our File Ref: B14101TL001
Contact: Steve Williams



We believe that the correspondence attached is adequate and appropriate at this stage.
As part of the detailed design process we could provide a more detailed tree
identification survey if this were considered appropriate and work with Council with
respect to any replacement planting.


2.     Alternate Access Route
The current access route for the vehicles associated with the proposal would result in
vehicles travelling to/from the Bruce Highway via Top Forestry Road, Old Ceylon Road,
Cooroy-Belli Creek Road, Maple Street, Crystal Street and Myal Street as represented
by Figure 3-1 of our initial traffic assessment report (see attached Figure 3-1).

As requested by Council we have considered the potential for an alternate access route
to/from the site. The two options contemplated include:

•      travelling to/from the Bruce Highway via Top Forestry Road, Old Ceylon Road,
       Cooroy-Belli Creek Road (through Ridgewood), Skyring Creek Road and
       Eumundi-Kenilworth Road; and
•      travelling to/from the Bruce Highway via Top Forestry Road, Old Ceylon Road,
       and Eumundi-Kenilworth Road; and

The initial alternate route noted above would result in additional 19km of travel which
over the life of the project would be completely unviable. From a strictly traffic
engineering perspective this would result in significant additional travel costs and
distance travelled on the local road network by heavy vehicles associated with the
proposal prior to gaining access to the higher order road network. This alternative would
require the vehicles to travel via Cooroy-Belli Creek Road through Ridgewood which
includes a section of sealed one-lane road which, based on Councils position with
respect to Top Forestry Road, is likely to result in additional upgrades being required by
Council. This route has a number of relatively winding sections of road and some
grades that are not encountered on the preferred route via Cooroy. This route is not
considered to represent a viable and importantly reasonable alternative.

The second route would be similar in distance to the preferred route. However this
alternate route, involving initially travelling south on Old Ceylon Road from Top Forestry
Road rather than initially heading north through to Cooroy-Belli Creek Road, would result
in vehicles associated with the use needing to traverse a number of narrow section of
road including one lane/two way sealed sections of road and additional unsealed road
sections of a lesser standard than the existing form of Top Forestry Road. As noted
above, based on Councils position with respect to Top Forestry Road, it is then likely that
this alternate route would result in additional upgrades being required by Council. This
route is not considered to represent a viable and importantly reasonable alternative.

Importantly the travel route previously identified and as preferred by our client is on our
view the most appropriate route from a traffic engineering perspective. Further we are of
the understanding that issues associated with noise have been addressed as part of the
noise reports prepared by others.

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25 May, 2015                                      -5-
Our File Ref: B14101TL001
Contact: Steve Williams




We believe that the proposed vehicle travel route associated with the proposal utilising
short section of roads through Cooroy, namely Maple Street and Crystal Street, is
acceptable from a traffic engineering perspective and is considered to be the most
appropriate route for the subject development.


Yours faithfully
For and on behalf of
LAMBERT & REHBEIN (SEQ) PTY LTD




S.A. WILLIAMS BE(Civil), MIEAust RPEQ
DIRECTOR
TRANSPORT & INFRASTRUCTURE


Enc:   Top Forestry Road Concept Design Plans
       Geotechnical Investigation Report - Red Earth Engineering (dated April 2015)
       Ecological Advice - L&R Letter (dated 14/05/2015)
       Pavement Design Profile - Circly Outputs