In brief

In 2000, the Senegalese capital Dakar faced severe traffic congestion and high levels of pollution. Recognising the challenge to the country’s economic growth if the infrastructure were not improved, President Abdoulaye Wade initiated the construction of a 32km toll highway from Dakar to the new economic hub of Diamniadio. The project was completeded in 2015, diverting 45,000 vehicles from Dakar's city centre and reducing the travel time between the two cities from an hour and a half to 15-30 minutes.

The challenge

Dakar is the capital of Senegal and has a population of nearly 2.5 million. It is situated on a peninsula at the westernmost point of Africa, and is therefore "well positioned to serve as a business and trade hub for the region".[1] However, in 2000 Dakar was experiencing severe traffic problems: the number of vehicles in the city strained its infrastructure, and traffic jams adversely affected the region’s economic growth as a whole.

Dakar’s population grew by more than 40 percent to 2.43 million between 1995 and 2005, while the number of vehicles doubled from 40,000 in 1997 to 98,000 in 2007. “Bumper-to-bumper traffic became the norm, and driving the 32km from Dakar’s downtown business district to the town of Diamniadio took an average of 90 minutes.”[2]

The negative impact of such congestion was considerable. “In 2008, the World Bank estimated that Dakar’s traffic troubles were costing Senegal at least XOF42 billion (about USD86 million at the time) per year, or 0.64 percent of 2008’s gross domestic product. Senegal’s Agency for Investment Promotion and Major Works (APIX) estimated the losses were more than twice as large, at XOF100 billion  (US$205 million) per year.”[3]

In addition to their effect on economic growth, traffic problems resulted in complicated health issues for Dakar. In 2005, the maximum acceptable level of PM10 particle concentration in the air as defined by the World Health Organization (WHO) – a daily mean of 20 µg/m3) – was regularly exceeded by a factor of two.[4] This specific type of micro dust is associated with lung cancer and respiratory diseases such as asthma.[5]

The initiative

Given the severe challenges Dakar was experiencing from the growing amount of traffic, the Senegalese government reconsidered the option of a new highway to ease road congestion, one that had previously been planned but never executed.[6]

In 2000, the government gave the newly-established APIX organisation the responsibility of supervising the proposed Dakar-Diamniadio Toll Highway (DDTH) Construction Project. The first of four phases began in 2005 and the entire project was scheduled to be completed by 2014, creating a 32km toll highway connecting Dakar with the new economic hub of Diamniadio. There were to be "five toll zones, five interchanges, a partition and security wall for houses built along the highway, 21 crossing infrastructures and 15 road passages to ensure continuity of a road link running across the highway along a 25.5km road length".[7] This affected a significant number of households: "part of this population (about 30,000 people) living in the road area will be displaced", and therefore needed to be resettled.[8]

The public impact

In October 2015, after the DDTH was completed, 45,000 vehicles on average were using the toll road every day, alleviating the congestion in Dakar city centre.[9] The travel time between downtown Dakar and Diamniadio decreased substantially from over 90 minutes to 15-30 minutes driving time. At the same time, the non-toll traffic routes remained in operation, and the traffic could therefore be split, creating more room for vehicles.[10]

Reduced travel times have resulted in substantial fuel savings and consequently in less pollution. The project has also facilitated the closure of an open-air waste site in Mbeubeuss and the creation of a new, greener landfill site.[11] In addition, it has contributed to the construction of new sanitation services and the reforestation of the surrounding area.[12]

The toll model has resulted in the anticipated amounts of revenue and has created a steady income stream. On average, the total cost of travelling on the DDTH amounts to XOF800 for motorcycles (~USD1.5), XOF1,400 for cars (~USD2.5) and XOF2,700 for lorries (~USD5). With a throughput of ~40,000 cars per day, this leads to a daily revenue of XOF56 million (~USD100,000 per day) from cars alone.[13]

Apart from its direct effect on of traffic volumes, the project has also helped to reduce poverty and improve living conditions for local communities within the affected area. Overall, 930 jobs (800 during the construction phase and 130 after the launch phase) were created by the project, generating a positive economic impact for the local population.[14] Furthermore, urban mobility has improved and more people have access to security, transport, administrative, health and education services in Dakar city centre.[15]

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What did and didn't work

All cases in our Public Impact Observatory have been evaluated for performance against the elements of our Public Impact Fundamentals.


Stakeholder Engagement Strong

The broad collaboration between the Senegalese government, private companies, and international development organisations created a fruitful climate for the DDTH project. The principal funding was provided jointly by the Senegalese government, the World Bank, Agence Française de Développement (AFD), and the African Development Bank (AfDB). APIX’s efforts in creating the first successful public-private partnership (PPP) in the region, which was formally established halfway through the project in 2009, demonstrated the strong collaboration between public and private institutions.

Rather than design the whole project and then select a bidder, APIX preselected a number of private contractors. Together with these contractors, APIX staff  designed technical specifications for the construction, how the PPP should operate, and filled in details of what was expected from the PPP contractor(s) in this cooperative venture. For example, they adopted “proposals on spacing the pedestrian overpasses based on population density and adjust[ed] the design so their construction would not affect traffic”.[16] This helped make the highway more cost-effective, and also informed the contractors of what was specifically required of them.[17]

APIX collaborated closely with international development organisations to secure additional funding. While the private sector was meant to finance 42 percent of the cost, APIX still had to cover the remaining 58 percent with funds from the government and other parties. Hence, in parallel with discussions with private companies on the design of the PPP, APIX facilitated joint meetings with international organisations, including the World Bank, the AfDB, and the French, Japanese and South Korean development agencies. They made sure that “the financing plan, the loan conditions, the Aide Memoire and performance indicators of the project were jointly prepared”.[18] At the same time, the different project designs that were proposed by the private bidders were reviewed by the development organisations, who were able to share their experiences from similar projects.

APIX collaborated closely with the World Bank on assessing the social and environmental impacts of the projects. Of specific concern were the 30,000 people who needed to be resettled in order to construct the highway. There existed a strong commitment to this social aspect of the project because “the Senegalese government and international donors wanted to ensure that people affected by construction of the highway were treated fairly”.[19]

Political Commitment Strong

Former president Abdoulaye Wade was the driving force behind the DDTH project, in that he created APIX and also wanted the project to be run eventually under a PPP. The government indicated its commitment by initiating the construction the first 12km of road – from Dakar to Pikine – and ensuring that the eventual toll would remain affordable for the average citizen, fixing tariff levels that were socially acceptable to all those involved.[20]

In the run-up to the 2000 Senegalese elections, in which he was a candidate, Abdoulaye Wade made the construction of new infrastructure, such as the DDTH and a proposed airport, one of his core election campaign promises. After his election victory, he set up APIX and tasked it with deciding how best to implement his infrastructure ideas. "The new president had long been interested in PPPs and wanted to finance the project through a build-operate-transfer agreement, in which a private company contributes funds to construct a highway and maintains it for a specific number of years in exchange for a revenue stream based on tolls.”[21]

From the initial idea to set up a PPP, it took over nine years of negotiations with the different stakeholders before signing the contracts. However, in 2005 the government was obliged by the political urgency of Dakar's traffic congestion to initiate the construction of the first 12 km of the DDTH – from Dakar to Pikine – through a traditional government procurement process.[22] “The first section was considered too urgent to wait, and the government saw that section as a way to demonstrate its commitment.”[23]

Public Confidence Good

There have been no public opinion polls on the Senegalese citizens' attitudes towards APIX or the DDTH specifically. However, there was a substantial degree of trust in President Wade during his early years in office. In addition, the project management team made significant efforts to ease potential tensions with residents who were affected by the construction.

During his first successful election campaign, Abdoulaye Wade met with substantial support from the Senegalese electorate and, according to the New York Times, emerged as a global "spokesman" on Africa. This indicates that, to some extent, the public was convinced by his ideas and also re-elected him in the next election to serve until 2012.[24] Afrobarometer public opinion survey data from 2002 suggested that 72 percent of the Senegalese population trusted its president "a lot" or "a very great deal".[25]

In order to avoid a backlash from residents, APIX and the World Bank planned to improve the sanitation services and access to social services in residential areas along the DDTH. They refurbished the drainage systems – as the area was prone to flooding – and built schools and health clinics. Residents who had to resettle were aided by three contracted, independent NGOs, such as ENDA ECOPOP, who helped residents receive adequate compensation for their resettlement. These NGOs conducted private house visits to ensure that every resident would be able to receive compensation.[26]


Clear Objectives Good

The DDTH project's main goal was to construct a highway that would reduce road congestion in Dakar. To address the issues arising from that, the project had the following principal objectives:

  • Improve the overall operation of the transport system in order to support an accelerated growth strategy and promote regional integration.
  • Provide a rapid link between the heart of Dakar and the city of Diamniadio, gateway to a new economic development area, and improve the environment of people living near the road.[27]

Evidence Strong

The combination of knowledge-gathering by APIX and an insightful, evidence-based evaluation of the construction of the  first 12km stretch of highway created a sound evidence base for the subsequent construction phases conducted under a PPP.

As there was relatively little knowledge of PPPs in Africa, APIX decided to send its staff to countries in Europe and South America – where PPPs had been implemented successfully – in order to learn from their experience. In addition, they hired a French engineering company to study the potential benefits of the project and how the highway was likely to be used, calculating the expected amounts of vehicles per day, for example. This proved crucial in predicting the revenue stream and deciding on practical issues such as the number of lanes.[28]

The construction of the first 12km of road proved a crucial source of evidence, which was very valuable in avoiding future problems. Eiffage, a French construction company which was awarded the PPP in 2009, was able to take into account several high-level studies which had been prepared by APIX and others in their final bid. One such document was the African Development Fund's 2008 Summary Report of the Environmental and Social Impact Assessment of the DDTH.[29] Legal, financial and technical experts provided evaluations of the technical issues which had arisen during the initial construction phase.[30]

Feasibility Strong

The financial feasibility of the DDTH project was principally secured by the Senegalese government and a number of international development organisations (see Stakeholder Engagement above).

The legal feasibility of the PPP aspect of the project was established a year before construction began. In 2004, the Senegalese parliament passed the law that formally authorised the use of PPPs in infrastructure projects – the 2004 Build Operate and Transfer Law (loi 2004-13 du 1er mars 2004), later amended by the 2014 Public Private Partnership Law (loi 2014- 09 du 20 février 2014. The 2004 law stipulated formal procedures for the bidding process and served as a template for other countries in the region. It also created the Infrastructure Council to serve as an oversight body supervising the bidding process and tackling any potential for corruption.[31] These measures established the necessary legal framework, although the PP itself did not take effect until halfway through construction.

In selecting the most effective method for constructing the section of the DDTH from Pikine to Diamniadio, APIX identified four possible construction options, which were evaluated based on their financial cost as well as their social and environmental impact. In order to find the best route for the DDTH, APIX concluded “a detailed multiple criteria analysis, based on technical, social, economic, financial, environmental and mobility criteria”.[32] At the same time, “environmental impacts have been identified, and mitigation measures incorporated in the project”.[33] It was also important from the start that the project remain financially profitable.[34]

APIX staff were trained by international organisations, such as the AFD, which conducted initial training on procedures before and during construction. Eiffage, the contractor for the PPP component of the project, had previous experience of infrastructure projects in Senegal – such as building the Dakar harbour – and of major motorway projects in France and elsewhere.


Management Good

APIX and Eiffage created their own project management bodies to establish a sense of collaborative management. Eiffage created its own special purpose operation, SENAC SA, to finance and build the highway and to continue operations for the next 30 years. Simultaneously, APIX created its own project management mechanism – the Direction du Projet Autoroute (DPA) – which managed the PPP and related components on behalf of the Senegalese government.[35]

In order to attract experienced engineers, environmental specialists and other highly-qualified staff to the project, APIX negotiated with the World Bank to offer very competitive salaries to attract skilled personnel. Additionally, APIX was also willing to hire experienced consultants as the team grew to include technical, financial and legal advisers.[36]

Measurement Strong

The DDTH project benefited from sound monitoring processes which were provided by several actors. Joint donor supervision missions, mid-term reviews, final evaluation and completion reports throughout the project ensured that performance indicators were measured on a constant basis and adjusted over time.

APIX and its DPA project management team monitored specific performance indicators, such as the urban mobility index and the improvement of transport conditions over time. For that, they entered into partnership with Egis International, which had been involved in researching the conditions for the highway before construction began. The indicators were monitored regularly, had clear implementation timeframes, and were measured based on a mixture of surveys with the project beneficiaries, site visits, and project supervision reports. The DPA established a steering committee to organise periodic meetings – which were open to civil society – and ensure the effectiveness of the monitoring process.[37]

SENAC also conducted its own monitoring. For them, the most important aspect of monitoring was tracking the physical construction process via site visits. They hired the French engineering firm Setec to supervise and monitor the work in progress on a daily basis and subsequently fed the information back to Egis.[38]

International development organisations such as the World Bank monitored both the public and the private aspects of the project. The World Bank, the AFD and the AfDB met regularly with APIX and SENAC to visit the construction sites, and the World Bank coordinated the international donors in their monitoring efforts. “The World Bank’s project team typically handled issues related to procurement procedures and the compensation policies for social and environmental impacts, in collaboration with the other donors”.[41] Additionally, other investors, such as the AfDB and the West African Development bank, conducted monitoring efforts carried out by their own independent supervisory technicians.

Alignment Good

The start of the project in 2005 was one of a number of important infrastructure projects under President Wade. When he was elected in 2000, he proposed the construction of a new international airport next to the DDTH, recognising that infrastructure improvement and integration would help the country develop economically. In 2014, the highway was planned to be extended to the new airport, ultimately connecting the two projects.

The Senegalese government and the international development organisations were well aligned on funding issues. “The [AFD] and the AfDB offered loans for construction of the highway itself and… the World Bank funded most of the remaining social and environmental components”.[38] The contractor Eiffage was able to secure additional funding from the West African Development Bank and CBAO, a Senegalese commercial bank. This created a secure funding environment that allowed APIX and SENAC to function properly and hire trained staff.[39]

APIX’s DPA involved all stakeholders in their monthly review meetings to discuss project progress. These meetings were open to all stakeholders, such as the international development organisations, the relevant government ministries, and local communities. Through these meetings it was possible to coordinate joint activities and resolve day-to-day problems which did not require a high-level policy decision. For example, the Directorate of Forest and Water in the Ministry of the Environment of Senegal was able to collaborate in managing the DDTH's environmental impact on the Mbao forest. Communities situated near the forest used it for farming and pastureland, but parts of it had to be deforested to make way for the highway. Aligning all stakeholders to preserve the remaining parts of the forest, including the Ministry of the Environment, the World Bank, APIX, and local communities, was made possible via these meetings.[40]


A New Route to Development: Senegal’s Toll Highway Public-Private Partnership, Maya Gainer, and Stefanie Chan, 2016, Innovations for Successful Societies, Princeton University

Afrobarometer Online Analysis Tool, Data 2002/2003, Politics and Society, Trust in the President, Senegal [accessed January 2018]

Executive Summary of the Environmental and Social Impact Assessment: Dakar Toll Road Project – Phase 2 Diamniado-AIBD Section, Mark Dimmer and Siala Fourati, April 2014, The African Development Bank Group

Health Effects of Particulate Matter – Policy implications for countries in eastern Europe, Caucasus and central Asia, Joint WHO/Convention on Long-Range Transboundary Air Pollution Task Force on Health Aspects of Air Pollution, 2013, WHO

Launching of the Dakar-Diamniadio motorway, Latest News, 12 February 2010, Eiffage

PPIAF Supports a Pioneering Transaction in Africa: The Dakar-Diamniadio Toll Road in Senegal, 2015, PPIAF

Project Appraisal Report – Dakar-Diamniadio Highway Project, Bamory Traore, 2009, The African Development Fund

Profile: Abdoulaye Wade, 2012, Al Jazeera

Road infrastructure in Africa, Africa Energy Forum 2016, 1 June 2016, Ashurst

Senegalese Loner Works to Build Africa, His Way, Onishi Norimutsu, 10 April 2002, The New York Times

Senegal moves into the fast lane with the opening of its toll highway, African Development Bank Group [accessed January 2018]

Summary of the Financial and Social Impact Assessment – Senegal: Dakar Diamniadio Highway Construction Project, B.K. Traore, September 2008, African Development Fund

Toll Roads Save Time and Create Jobs in Senegal, April 2016, International Finance Corporation

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