Hoping to kill two birds with one stone in its bid to relieve traffic congestion in Athens, the government may offer incentives to taxi drivers to exchange their vehicles for public buses. Transport Minister Michalis Liapis said yesterday that the ministry is studying a proposal by taxi unionists for cabbies to participate in a projected new, larger public transport network to be run by municipal authorities. Some 15,000 taxis currently ply the capital’s streets, exacerbating transport woes in the city of 4 million. Ministry sources told Kathimerini that one idea would be to issue one bus license to every three taxi drivers who agree to withdraw their vehicles from circulation. But Athens taxi unionists voiced skepticism yesterday. The ministry is expected to present its final proposals on Athens transport two weeks from now.