AECOM was appointed to provide comprehensive consulting engineering services, covering the entire R573 Moloto Road Section 2 Upgrade project lifecycle from the assessment and reporting stage to design, tender documentation, contract administration and close-out. This project involves road upgrade between Moloto and Moteti, entailing the construction of approximately 49 km of new carriageway, significantly enhancing safety and mobility.
AECOM’s role
AECOM’s scope of work is to redesign the existing road as two lanes in either direction, along with public transport facilities. It includes widening five river bridges, ten major culverts and three pedestrian bridges. In addition, a median barrier will be constructed as a major accident-prevention measure, along with street lighting to improve visibility.
The fact that the road is being upgraded from Category 3 to Category 2 means that the existing bulk stormwater system immediately adjacent and outside the R573 road reserve cannot cope with the design peak flows. As such, these systems also need to be upgraded in order to mitigate flooding. This has necessitated additional major culverts, bulk stormwater channels and low-level crossings. AECOM also needed to reinstate access and provide road linkages to the new intersections, mainly as a result of cutting off indirect accesses onto the R573, so that this then becomes part of the overall road network. The access roads and bulk stormwater drainage forms part of corresponding community development projects.
Environmental, social and governance commitment
To improve efficiency, the project utilized the existing in-situ material from the original single carriageway road for a portion of the layerworks for the new widening, as well as locally available commercial material sources. Utilising existing material is a fundamental approach to ensuring environmental sustainability in terms of optimum usage of existing materials.
The main works contracts made provision for a minimum 30% Contract Participation Goals (CPG) target to Targeted Enterprises and SMMEs. The tender was originally awarded on the basis that there will only be two main works contracts. It has since developed into one priority works contract and five main works contracts. Of these, one Main Works Package A, is nearing completion with AECOM providing construction administration and monitoring of this Works Contract. In addition to this a component of the works and design philosophy was to improve pedestrian safety through the provision of sidewalks in the urban/ peri-urban areas as well as formalised crossing points along the entire route and the construction of pedestrian bridges. For the community development projects the focus is to reinstate access to properties affected by the main road upgrade, taking into considering spatial constraints and how this tied into the overall access management plan and upgrades to the adjacent road network. This was achieved by formalising indirect accesses and developing the formal street network. The community development projects centred around these local accesses and associated bulk stormwater infrastructure upgrades and included the use of labor-intensive construction techniques and materials to construct these access roads, where possible.
Digital innovation
As part of the construction monitoring phase of the Priority Works contract, AECOM utilized advanced digital tools such as BIM 360 and ArcGIS for construction monitoring and management of the Priority Works contract. Key innovations included data captured and shared in cloud-based Common Data Environments (CDE) from construction sites to AECOM office locations. Three digital workflows were upgraded including daily site diaries using ESRI mobile apps, geo-located site progress photos captured via ESRI GIS apps and inspection along with approval requests ran on the Autodesk BIM 360 Field platform. Drone technology was used to collect real-time project data to track construction progress. To leverage the value of all this captured data, AECOM implemented data-driven digital dashboards to assist with visual analytics of weekly activities on-site.
Project management
AECOM provided planning and management of traffic during construction through half-width construction of the R573 while maintaining full traffic flow. This is facilitated by utilizing a temporary road widening and constructing the new carriageway, while the original carriageway was used to accommodate traffic. Upon completion of the new carriageway, traffic is then moved over to the newly constructed carriageway while the existing carriageway is rebuilt. Of primary importance is to ensure continued mobility and accommodation of traffic during construction.