Experience
Our experience
We apply our traffic and transport expertise to projects that range from local road upgrades to major infrastructure. That work typically pulls on our structural, geotechnical and civil teams in parallel, so clients can get a coordinated engineering response from a single consultant rather than stitching together specialist advice from several.
Modelling and analysis
Transport planning depends on credible modelling of how networks will perform under change. We use industry-standard tools including Aimsun, Legion and Transyt to run meso and micro-level simulations, pedestrian flow analysis and signal optimisation studies. The outputs feed directly into design decisions and into the cases we help clients build for funding and consent.
Traffic modelling and network simulation
Pedestrian and pedestrian-flow modelling
Heavy vehicle route assessments
Signal optimisation and corridor studies
Masterplanning for transport corridors
Infrastructure design
On the hard-infrastructure side we design the physical assets that carry the traffic. That covers roads and bridges, rail, and the retention and drainage structures that sit alongside them.
Road and pavement design
Bridge design and assessment
Retention structures
Rail infrastructure
Proof engineering and independent verification
Experience across New Zealand
Transport infrastructure is where most of our regional roading and coastal structures work sits, and a lot of it is reinstatement after something has failed. In Northland we assessed 380 landslides across the Far North District Council network, stabilised Kohukohu Road and Mangakāhia Road, and repaired the Pīpīwai Road dropout. On the East Coast we designed the revetment sections along East Cape Road at Te Araroa for Tairāwhiti Roads, remediated deep-seated landslides on Anaura Road, and built the retaining wall carrying Kaiti Hill Road in Gisborne.
Our marine and waterfront transport work includes the design and build of the 60-metre Pōuto Wharf on the Kaipara Harbour, upgrades at Sandspit Wharf, pile work at Ōrākei Wharf, and seawall repair and modifications at the Auckland Ferry Terminal. We also work on bridges, culverts and stopbanks, including the Donald Road and McLean Street bridges and emergency flood-protection remediation on the Heretaunga Plains.
380 landslide assessments and road stabilisation, Far North network
East Cape Road revetment, Te Araroa
Anaura Road landslide remediation and Kaiti Hill retaining wall, Gisborne
Pōuto Wharf design and build, Kaipara Harbour
Sandspit Wharf upgrades, Ōrākei Wharf piles, Auckland Ferry Terminal seawall
Donald Road and McLean Street bridges
Stopbank and flood-protection remediation, Heretaunga Plains
Roads that have already failed once
A large part of regional roading work is not new capacity, it is keeping an existing route open on ground that is moving. The engineering question is rarely what the best repair would be; it is what repair is worth doing given how much road is at risk, how long the network can tolerate a closure, and what the do-nothing option really costs over a decade. We set the options out with those trade-offs visible, and we stage designs so that a council can fund the urgent portion now without foreclosing the permanent fix later.
Recent Projects
Project Experience across our transport work.
Tauwhareparae Road Landslide
Tauwhareparae, Gisborne
LDE provided comprehensive geological assessments and analyses of the significant landslide and sections of the affected road. The road traverses across the top of a narrow section of the ridge which drops away steeply for several tens of metres on either side. The southern...
Northland Roading Network Preventative Landslide Investigations
LDE provided preventative landslide investigations for FNDC. We investigated and determined remedial solutions for ten large landslides affecting parts of the Northland roading network.
Pīpīwai Road Drop Out Repair
Northland
A dropout occurred within the road formation and undercut and removed the road pavement along Pīpīwai Road. Road access was also affected by the slips. Emergency remedial works were actioned to allow the road to reopen to traffic. To stabilise the wide area of land slippage...
Oneroa Walkway
LDE provided professional engineering services for the design of a concrete cycle and walkway alongside Centennial Marine Drive and Beacon Street. This walkway connected the Alfred Cox cycle and walkway and the Oneroa cycle and walkway. We were familiar with the project having...
Nuhaka River Road Landslide
Nuhaka
We assessed a massive landslide, measuring 2km in length, 800m in width, and 50m in depth, which caused the severing of Nuhaka River and Mangone Roads. Our work involved exploring options for diverting the river and realigning the roads to accommodate the landslide’s presence....
McLean Street Bridge, Pokeno
McLean St Bridge provides access a primary access road to several hundred residential lots being developed through the Pokeno area. It has a clear span of 28.5m and crosses both the North Island Main Trunk Railway Line and Pokeno Stream. The bridge will carry key service lines...
Mangakāhia Road Stabilisation
Northland
Land movement affected an approximately 70 m-long section of Mangakāhia Road and required a deeper level of investigation. LDE was engaged to carry out the investigation, design and construction supervision of an 11m high reinforced concrete anchored retaining wall.
Anaura Road Landslide Remediation
Anaura Road had continuously been affected by ongoing and significant land slippage, resulting in the frequent loss of carriageway width or total road loss as had now occurred. LDE determined the engineering geology of two vast deep-seated landslides severing the road. Works...
Kohukohu Road Landslide Stabilisation
Northland
The project’s purpose was to stabilise the lower area of a dropout located between the Kohukohu Township and the Hokianga ferry ramp and reconstruct the roadway. LDE provided engineering services for the remediation design and construction inspections for Colmix columns. After...
Kaiti Hill Plaza Retaining Wall
Gisborne
What was once a pa (fortified village) atop Kaiti Hill is now a 35-ha reserve and boasts impressive views of Gisborne city centre and its three rivers. The Hill is a popular spot for picnics, fitness and lookouts, and Kaiti Hill Road is the primary access to the reserve. Due to...
Hīhītahi Rise Landslide
LDE conducted a detailed geotechnical investigation and stabilisation of a large-scale, deep-seated suburban landslide. The investigation was to determine the nature and cause of the land instability affecting some 95m of the site. In addition to ongoing deformation in the road...
Crosses Road Bridge Geotechnical Investigation
Havelock North
LDE conducted geotechnical investigations for a bridge extension to accommodate a cycleway at Crosses Road. The cycleway was to be supported by the construction of an elevated steel framework and supported mainly by extensions to the existing concrete piers. Liquefaction and...