Roads 152 Design and construction 98 Transportation 65 Highway planning 57 Law and legislation 42 Planning 42 Maintenance and repair 31 more ... Environmental aspects 30 Drivers' licenses 27 Traffic safety 25 Licenses 24 Government policy 22 Bridges 20 Transportation and state 19 Contracting out 18 Traffic regulations 18 Affirmative action programs 16 Automobile driving 15 Traffic signs and signals 15 Automobile drivers' tests 13 Automobiles 13 Discrimination in employment 13 History 13 Inspection 12 Road construction contracts 12 Drunk driving 11 Drinking and traffic accidents 10 Motorcycles 10 Right of way 10 Services for 10 less ...