SUBJECT
Roads
21
Bridges
16
Design and construction
16
Maintenance and repair
16
Management
13
Pavements
13
Transportation
10
Data processing
8
Safety measures
7
Testing
6
Environmental aspects
4
Live loads
4
Planning
4
Specifications
4
States
4
Traffic safety
4
Transportation agencies
4
Concrete bridges
3
Floors
3
Highway departments
3
Highway engineering
3
Inspection
3
Quality control
3
Road markings
3
Subgrades
3
Traffic flow
3
Culverts
2
Evaluation
2
Highway communications
2
Highway planning
2
Highway research
2
Intergovernmental cooperation
2
Joints
2
Law and legislation
2
Letting of contracts
2
Management information systems
2
Median strips
2
Performance
2
Research
2
Road construction contracts
2
Road drainage
2
Road materials
2
Security measures
2
Standards
2
Technological innovations
2
Technology transfer
2
Traffic engineering
2
Transportation and state
2
Trucks
2
Accessories
1
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