4. TRANSPORTATION PLANNING AND ROADS
4.1 Transportation Planning
This chapter covers the transportation aspects of the Xai-Xai Beach IDP. The recognition of the transportation needs of the community and stakeholders in the Xai-Xai coastal zone forms the basis for the design of appropriate transportation systems. Failure to provide sufficient transport infrastructure or services will lead to uncontrolled settlement and accesses, which can lead to the destruction of sensitive areas. This transportation assessment was based on observations and through participation in the planning process. The assessment is mainly conceptual, except with respect to route determinations done in Praia Velha Demonstration Project area and along the backset distributor road. The focus of the roads planning was to contribute to the physical development framework.
Proposals with respect to funding of road construction will be discussed under the institutional framework. The cost of road construction was based on unit rates used by the provincial roads maintenance department in 1998. Road construction cost is very high due to the poor quality of local construction material.
4.1.1 Environmental Considerations
The environmental impact of development was a serious concern throughout the planning. The impact of roads is specifically important, as roads open up the area and change drainage patterns. The geology of the area is recent sands, formed into dunes under maritime influence. The dunes are orientated perpendicular to the coast, resulting in steep valleys with depressions as low as 2m above sea level and dune crests as high as 126m above sea level. The dunes perpendicular to the sea, allow some possible routes from the inland, but limit routes parallel to the coast. The topography of the coastal dunes is not very suitable to development, as many of the slopes are too steep for building and roads will have to cut through the dunes. The exposed dune sand is unstable and prone to wind erosion. The implication for roads planning is that design standards must be restricted to fit the horizontal and vertical alignments to the natural constraints. Routes should follow contours as far as possible and where slopes are required, the route must follow natural slopes of acceptable gradients. The natural vegetation must be retained as far as possible during construction of roads and slopes resulting from cut and fill operations revegetated. Storm water runoff from roads must be channelled in side drains to avoid erosion and weakening of the sub grade. Storm water is absorbed into the sand or accumulated in the natural depressions. This drainage patterns should be left as undisturbed as possible. The area is subject to cyclone conditions. Final design of drainage must take this into account.
4.1.2 Transportation Planning
Transportation planning, including the evaluation of alternative solutions and proposals on infrastructure and services, in the context of this project was taken to be the determination of the mobility needs of the community within the proposed development framework. The planning is based on extensions of existing patterns. The planning gives possible scenarios for the future and is not tied to a specific time or investment framework. It is not a set of decisions, but provides input into the decision making process.