Design process and outputs

The company can in cooperation with other design institutions undertake design projects on highways, intercrossing and interchange roads, bridges, culverts, by following the design procedures below.

Major road projects approval procedure requires a project proposal and design specification manual (equivalent of the feasibility study report) to be approved to ensure that the proposal and specifications accord with the requirements of the national long-term economic planning, regional industrial planning requirements. 

Construction approval from local authorities for all new and upgraded highways involves many areas relating to the design aspects that go into more technical detail. The company’s design team takes note of any updates that become necessary as and when required in relation to changes to standards, codes of practice, as well as other documents that reflects local authority variances.

Generally, the design team will give two sets of design deliverables: Preliminary design and detailed working drawings.

In order to produce the preliminary design, preliminary field survey and measurements and economic investigation will be done along the approved route to collect initial field survey data and establish control systems. This survey will also map all physical land features along the project area to establish reference to the route location for comprehensive design considerations. The results of the preliminary survey are the basis for the preliminary design and cost estimate of the project which should be aiming to be practical, economic, reasonable, safe, applicable, and artistic, in harmony with the environment and in line with the requirements of traffic engineering.

Preliminary design deliverables:

(1) Design Specification manual, which consists of an overview of the design outputs, technology preparation, economic evaluation of the recommended proposals and proposals as to optimal solutions plus analysis of outstanding problems and matters needing attention.

(2) Bill of engineering quantities and table of the main materials needed.

(3) Engineering Budgetary Estimates: budget for the preparation of the quota, the standard rate, the basis for material pricing, construction method and construction cost;

(4) Design drawings including road location schematic diagram, topographic plan (including land acquisition and demolition), profile diagram, cross section map, road crossing and square design, virescence area plan and lighting arrangements along the road.

After the preliminary design is approved, detailed technical survey (Geotechnical survey, topographic survey road base and pavement survey, bridges, culverts and irrigation pipeline survey and economic survey) will be conducted for the preparation of more detailed working drawing designs.

Detailed working drawing design consists of:

(1)  Road plan and profile with detailed measurements and elevation marking;

(2)  Composition and thickness of the pavement structure design;

(3)  Drainage structure design;

(4)  Working drawings of small and medium sized bridges, culverts, irrigation channels and other ancillary structures with details of locations, elevations, boring diameters and necessary construction instructions.

(5)  Engineering rough calculations taking into account land acquisition, house demolition, pipelines and obstacles removal.

(6)  Where there are discrepancies with the preliminary design, revise the preliminary design and budget estimates and submit for re-approval.