01. October 2019

Feasibility study, detailed planning, evaluation of offers and construction supervision of the “Tongatapu and Outer Island Roads Works” in Tonga

One of the roads, that is going to be renewed in the scope of the project

The project team with representatives of the customer

Map of the roads to be rehabilitated on Tongatapu

Within the framework of the “Tonga Resilient Transport Project (“TCRTP”), the government of the Kingdom of Tonga in Polynesia commissioned the working community of engineers from GAUFF GmbH & Co. Engineering KG and IMC Worldwide as consultants for the rehabilitation of approx. 155 km of roads. The contract of the project that is financed by the World Bank, has been signed in January 2019.

The consultancy services include

  • in Part 1 the updating and enhancement of the existing technical specifications for the roads (development of new specifications for climate-resistant solutions for roads and road surfaces on hilly ground),
  • in Part 2 the feasibility study with detailed planning and execution planning for 100 selected roads on the islands of Tongatapu, Vava’u, Ha’apai and ‘Eua,
  • in Part 3 the construction supervision of selected roads, compiled from Part 2 of the assignment and finally
  • in Part 4 the multiannual and performance based execution of the construction agreement as well as an annual supervision of the roads during the guarantee period in the western part of Vava’u and/or Ha’apai and/or ‘Eua.

The rehabilitations measures consist of a combination of renewal as well as modernization of the road surface, new drainage devices as well as routine maintenance and emergency measures. The detailed engineering design refers to 150 kms of roads, the construction supervision refers to up until 110 kms.

For Part 1, 100 roads with approx. 155 km in length have been measured, the actual condition of the road damages were evaluated, the required measures for drainage have been determined, the expected social and environmental impacts have been identified and potential stone quarries have been defined for the supply of material. Then, a technical feasibility study was performed with all the criteria like f. ex. estimated benefits, road safety or efficiency. Typical design solutions for the drainage and the renewal of the road surface were elaborated in the detailed engineering design. The invitation to tender is going to consist of two possible contractual approaches: on one side a traditional tender for a building contract with construction and support during the guaranty period , on the other side the tendering of a performance based construction contract (Performance Based Contract – PBC). The tendering for the biggest part of the 100 roads is going to be launched via PBC. The working community of engineers has already developed a strategy for sourcing as well as planning for both contract variants.

The construction supervision following the evaluation of the offers and their placement is going to take eleven or even 15 months itself. It is the goal of the customer to perform the construction supervision himself after round about one year. For this purpose, the working community of engineers is going to introduce and convey to the customer all necessary basic knowledge for the construction supervision in workshops. A study tour to New Zeeland should enable an exchange of experiences with the local institutions.