Turkey opens record-breaking bridge between Europe and Asia
https://edition.cnn.com/travel/article/turkey-worlds-biggest-bridge/index.html
Turkey focuses on transportation between Asian side and European side. Though the political plan itself is to be praised, the country should think about what passes the strait.
When it comes to freights moving between Europe and Asia, there is no freight train on Marmaray. Though trucks can pass through 1915 Çanakkale Bridge or Bosphorus Bridges, the quantity per one truck is limited.
When it comes to passengers between other European and Asian countries, urban rails over Marmaray and long distance trains won't be used, due to travel time. So, high speed rails over the strait will be needed.