Performance Review of the N14 Road in Mozambique

 

CDS was commissioned by the Swedish Embassy in Maputo in 2013 to conduct a mid-life performance review of the N14 road in Niassa Province.

The N14 road links the port of Pemba to Lichinga in northern Mozambique, a total distance of 732km. The road is being progressively upgraded to paved standard in response to demand and with the availability of funds. The section of the road that was the subject of this study is from Litunde to Marrupa in Niassa Province. This section was constructed to a 7 metre wide paved standard between 2003 and 2006 with funding from Sweden. The length of the section is 247km. Before construction most of the road comprised an earth track.

At an early stage of the project the pavement design was altered from a conventional high standard approach requiring crushed stone material in the upper layers to a Low Volume Sealed Roads (LVSR) design standard using locally available laterite material in the road base. As a result of this change it was posible to surface the entire length of the road with the funds available, as opposed to leaving most of the road unsealed until more funds could be sourced by the government. The road carries very little traffic yet is of strategic importance to the economic development of the north of Mozambique.

N14 2

Pavement Strength Testing on the N14

The objective of the study was to establish 1) whether changes to the design of the road pavement prior to construction were justified, and 2) what can be learnt about the performance of unstabilized natural gravel materials in pavements for low volume roads. The output of the study will feed directly into a longer term objective of the government to develop new pavement design standards for Mozambique. It compliments similar research currently underway in Mozambique and the region through AFCAP.

The outcome of the study was that the road is performing well mid-way through its design life and the design changes were clearly justified. Lessons were learnt on the construction of LVSRs including the importance of compaction to refusal to obtain the best performance from non-conventional pavement materials, the benefits of sealed shoulders, and the need for flexibility in the design of the road.