1. Road Network Upgrading And Overland Trade Expansion In Sub-Saharan Africa Piet Buys Uwe Deichmann David Wheeler Development Research Group

2. Dakar Nouakchott Banjul Conakry Freetown Monrovia Bissau Abidjan Accra Lome Cotonou Bamako Ouagadougou N’Djamena Abuja Yaoundé Bangui Niamey Libreville Brazzaville Kinshasa Khartoum Asmara Djibouti Addis Ababa Kampala Nairobi Mogadishu Dar es Salaam Luanda Windhoek Lusaka Lilongwe Maputo Harare Bujumbura Kigali Gaborone Maseru Mbabane Pretoria Sub-Saharan Africa: Continental Capitals & Cities>500,000 Population

3. Least-Distance Network: Total Length: 108,000 Km. 885 Road Segments 3,403 Connected City Pairs

4. Our “Resumé” PB, UD, DW Overland Travel

5. Road Network; Current Network Quality

6. Benefit – Cost Analysis for Network Upgrading at Different Scales: Using The Network Model For Road Improvement Strategy Continental Regional National Sub-National (data permitting)

7. Economic Scale (Population x Income Per Capita) = Network Trade Factors Economic Scale Road Distance Road Quality Trade Agreements Benefits : Trade Flows Between Cities & Countries

8. Estimating Trade Flows: Econometric Analysis via Gravity Modeling Data Source: IMFDOT, 2000-2003 Sample Size: 1128 Observations Results: t-statistics in parentheses [** => 99% confidence]

9. Gravity Model Application: Projecting Network Trade Flows ($US) 1 2 3 4 5 Road Quality Best Worst Program: Network Upgrade to Class 2

10. Gravity Model Application: Network Trade Flows ($US) Current Total for SSA: $10 Billion

11. Gravity Model Application: Upgraded Network Trade Flows ($US) Econometric Projection: $30 Billion

12. Gravity Model Application: Network Trade Flows ($US) Program: Network Upgrade to Class 2 10.1 Current Econometric Projection: Annual Trade ($Billion) Upgraded 30.4 57.1 16.3 [+1 Std. Error] [-1 Std. Error]

13. Cost : Econometric Analysis of Road Projects 1 2 3 4 5 Road Quality Best Worst Program: Network Upgrade to Class 2

14. Data Source: World Bank ROCKS Database Sub-Saharan Africa: 470 Road Projects Costs in $US ‘000/Km. of Improvement

15. Cost Function Estimation Dependent Variable: Unit Improvement Cost Existing road condition (percent paved) Wage (per capita income) Governance (CPIA for accountability, corruption) Rainfall (Daily mean for primary road network) Regional controls (West, Central, East Africa) Project type controls: 7 Upgrading categories 6 Maintenance categories Independent Variables:

16. Projection From Estimated Cost Function

17. Program: Network Upgrade to Class 2 Econometric Projection: Upgrade Cost ($Billion) 20.7 28.4 15.6 [+1 Std. Error] [-1 Std. Error] Upgrade 0.9 1.2 0.7 [+1 Std. Error] [-1 Std. Error] Maintenance

18. Network Upgrade Program: 5-Year Upgrade; 10-Year Operation