The Project - The Evaluation - Overall Conclusion - The Main Findings - Lessons - Further Information

The Project

The upgrading of the Songea-Makambako road in Tanzania, funded by ODA, began in 1980 and was completed in 1985. The road, which is 322km long, is part of the national arterial transport network and links Songea, the regional headquarters of Ruvuma Region in Southern Tanzania with Makambako in the north, which is on the Tanzam highway. It is the only all-weather route between southern Tanzania and the rest of the country. The final cost to ODA has been £92m compared with the original grant of £39m. Costs met by the Government of Tanzania were £11m, as against £2m foreseen at appraisal.

The Evaluation

The evaluation was undertaken by a geographer from Lancaster Polytechnic, a sociologist from St Anthony's College, Oxford and a transport economist from IT Transport Ltd. Because of data inadequacies in the original socio-economic baseline study and the rapidly changing economic circumstances in Tanzania at the time of the study in late 1987, it was decided to undertake an interim evaluation, comprising a baseline survey of transport and socio-economic conditions along the road, an assessment of the short-term impact of the project and the identification of key variables needed to measure the road's impact, and proposals for monitoring them until a full evaluation is undertaken.

Overall Conclusion

The project was judged to have been partially successful, given that the cost of the road had risen substantially from that foreseen at appraisal, while the estimated rate-of-return is considerably lower than the opportunity cost of capital. This is a preliminary judgement pending the full evaluation.

The Main Findings

  • The IRR of the project, recalculated at evaluation is 5.8%, including the value of time savings, compared with 6% foreseen at appraisal, excluding time savings.
  • Traffic levels in 1987 were estimated to be similar to those forecast at appraisal although comparisons are complicated by the changing locations of traffic count sites between appraisal and evaluation. Over most of the road's length traffic is very low, below 100 VPD.
  • There have been significant savings in vehicle operating costs, foreseen at appraisal as the major quantifiable benefit, with costs falling between 50-62%.
  • There have been very considerable savings in journey times for light good vehicles of 63% per kilometre. Return trips by bus between Songea and Dar es Salaam have been reduced from around six to two days. One of the most widely perceived benefits is the improved reliability of travel.
  • The road was opened to traffic one year later than forecast at appraisal. Construction costs were 85% higher in real terms, because of the decision to build the road to a higher standard than initially agreed with the Tanzanian Government.
  • The benefits of reduced vehicle operating costs have been passed on to the local population primarily in the form of increased levels of passenger and freight services and not lower fares or charges because Government price fixing means these are still below costs.
  • The main socio-economic changes that have taken place since 1979 are the increasing commercialisation of peasant agriculture, greater integration of the two districts into the national economy, an increase in personal mobility and the accelerated growth of Songea, the regional capital of Ruvuma Region. The road has been a contributing factor to these developments, although it is not possible to isolate its influence from that of recent general favourable economic changes in Tanzania.
  • The Songea Makambako road has benefited two of Tanzania's poorest regions, Ruvuma and Iringa Regions which have a higher proportion of low income households than the national average.
  • It is necessary to monitor only a few key variables each year, on traffic flow and composition and on road maintenance costs, in order to generate data vital to a subsequent evaluation of the project.


  • Traffic counts should be undertaken at similar times of the year at carefully chosen sites which should not be relocated. Effective appraisal and evaluation of road projects requires that meaningful comparison can be made of a series of annual traffic count figures which provide information on the different types of vehicles. Changing times of the year and location can make comparisons meaningless.
  • Specific studies are needed at the before and after stage if an evaluation is intended to include the impact of a road project on the local economy or particular target groups. For ease of analysis and to keep costs at an acceptable level, such studies should entail minimum levels of data collection and focus on key variables.
  • The benefits of a road project will be reduced where the effect of government policies is to discourage private sector initiative.

Further Information

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