Road transport makes Brno an international crossroad of highways. There are two motorways on the southern edge of the city, D1 leading to Ostrava and to Prague and D2 leading to Bratislava. Not far from the city limits there is also the D52 motorway, leading to Vienna; another motorway, D43, which will connect Brno to northwestern Moravia, is planned. The city is gradually building the large city ring road (road I/42), several road tunnels were built (Tunnels Pisarky, Husovice, Hlinky and Královopolský) and more tunnels are planned. Also, due to the congestion in private transport the city continues to strive to build more parking ramps including underground ones, but this effort has not always been successful.