Road Network Upgrading

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Road Network Upgrading And Overland Trade
Expansion In Sub-Saharan Africa
Piet Buys Uwe Deichmann David Wheeler
Development Research Group
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Sub-Saharan Africa Continental Capitals
Citiesgt500,000 Population
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Least-Distance Network Total Length 108,000
Km. 885 Road Segments 3,403 Connected City Pairs
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Our Resumé
PB, UD, DW Overland Travel
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Road Network Current Network Quality
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Using The Network Model For Road Improvement
Strategy
Benefit Cost Analysis for Network Upgrading at
Different Scales

• Continental
• Regional
• National
• Sub-National (data permitting)

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Benefits Trade Flows Between Cities Countries

• Network Trade Factors
• Economic Scale
• Road Distance
• Road Quality
• Trade Agreements

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Estimating Trade Flows Econometric Analysis
via Gravity Modeling
Data Source IMFDOT, 2000-2003 Sample Size 1128
Observations
Results t-statistics in parentheses gt 99
confidence
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Gravity Model Application Projecting Network
Trade Flows (US)
Road Quality
Best
1
2
3
4
Worst
5
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Gravity Model Application Network Trade Flows
(US)
Current Total for SSA 10 Billion
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Gravity Model Application Upgraded Network
Trade Flows (US)
Econometric Projection 30 Billion
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Gravity Model Application Network Trade Flows
(US)
Econometric Projection Annual Trade (Billion)
Upgraded
Current
10.1
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Cost Econometric Analysis of Road Projects
Program Network Upgrade to Class
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Road Quality
Best
1
2
3
4
Worst
5
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Data Source World Bank ROCKS Database
Sub-Saharan Africa 470 Road Projects Costs in
US 000/Km. of Improvement
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Cost Function Estimation
Dependent Variable Unit Improvement Cost
Independent Variables

• 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

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Projection From Estimated Cost Function
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Program Network Upgrade to Class
2
Econometric Projection Upgrade Cost (Billion)
Upgrade
Maintenance
28.4 15.6
1 Std. Error
1.2 0.7
1 Std. Error
20.7
0.9
-1 Std. Error
-1 Std. Error
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Network Upgrade Program 5-Year Upgrade 10-Year
Operation