ground communication constructions roads 33 motorways 10 civil engineering constructions 10 road communications 10 concrete constructions 9 construction materials 8 more ... asphalt 7 road transport 7 road bridges 7 history 6 concretes 5 transport constructions 5 maintenance 5 stone 4 repairs 4 recycling of wastes 4 silniční stavby 4 simulation and modelling 4 technical standards 4 materials 3 surface 3 slags 3 exploitation 3 local roads 2 transport 2 traffic safety 2 traffic 2 traffic signs 2 airports 2 less ...