Ekici, Özgün2023-09-072023-09-072022-10ISSN 1305-5577http://hdl.handle.net/10679/8768https://doi.org/10.17233/sosyoekonomi.2022.04.06For many years, two toll bridges served commuter demand to cross the strait called Bosporus in Istanbul, Turkey. An underground connection called the Eurasian tunnel had been recently launched to relieve the strait's traffic. We study a simple transportation model that incorporates the forces that have come into play after the opening of the Eurasian tunnel. We find that for welfare maximisation, the premium paid for using the tunnel should be fixed in the two directions and not excessive. The current toll regime violates these features, and we recommend its amendment in light of our findings.engopenAccessarticle305412114400087768620000610.17233/sosyoekonomi.2022.04.06CongestionToll bridgesMixed duopolyRegulationBosporus