Istanbul Metropolitan Municipality has unanimously approved a six-tunnel-road project that will take vehicles underground. Inspired by road structures in Spain's capital Madrid and one of its biggest cities Barcelona, the project aims to bring a solution to the heavy traffic problem in Istanbul, where approximately 4 million vehicles are registered.A six-tunnel-road will be constructed with a "dive in - dive out" model, which will pass through Büyükçekmece, Esenyurt, Avcılar, Küçükçekmece, Bahçelievler, Bayrampaşa, Kağıthane, Sarıyer and Kilyos, taking 300,000 vehicles underground.According to Hurriyet Daily, the areas included in the plan have had bids unanimously approved by Istanbul Metropolitan Municipality (İBB) and have already been built on, and small parts are currently empty. The six-tunnel road will connect the TEM Highway and D-100. Some parts of the project route are included in disaster risk areas, some within unplanned areas and some under the authority of the Environment and Urbanization Ministry.Justice and Development Party deputy and Head of the Transportation and Traffic Commission Mehmet Yeter said nearly 300,000 vehicles are expected to pass daily through the tunnels, whose total length is planned to reach 23 kilometers. The project is predicted to cost up to TL 2.5 billion ($862 million).