Technical specifications for design and construction of highway in permafrost area Technical specifications for design and construction of highway in seasonal frozen soil region Technical specifications for design and construction of highway subgrade in loess region Technical specifications for design and construction of special road in automotive proving ground Specifications for design and construction of highway tunnels with gas Technical specifications for construction of highway gas tunnel Technical guidelines for design and construction of highway retaining walls Technical specification for construction of highway safety facilities Technical specifications for construction of highway tunnel Technical specifications for construction of highway bridges and culverts