SUBJECT
Roads
Transportation
Economic aspects
13
Design and construction
9
Planning
8
Maintenance and repair
7
Finance
6
Environmental aspects
4
Highway departments
4
Prevention
4
Safety measures
4
Security measures
4
Terrorism
4
Congresses
3
Hazardous substances
3
Management
3
Rural roads
3
Transportation, Automotive
3
Addresses, essays, lectures
2
Developing countries
2
Emergency transportation
2
Evaluation
2
Highway engineering
2
Railroads
2
Rural poor
2
Shipping
2
Toll roads
2
Transportation and state
2
Access roads
1
Accidents
1
Air travel
1
Automobile driving in winter
1
Bus industry
1
Buses
1
Capital investments
1
Case studies
1
Cities and towns
1
Climatic factors
1
Commercial vehicles
1
Communication and traffic
1
Computer programs
1
Congestion pricing
1
Consulting engineers
1
Control
1
Cost effectiveness
1
Costs
1
Economic development
1
Environmental impact analysis
1
Fares
1
Feasibility study
1
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