the excavation works at the tunnel were carried out from both sides. the breakthrough took place in july 2002 after 18 months of tunnelling. the -long tunnel carries one lane of traffic in each direction inside one tube. all the infrastructural installations for power supply, lighting, tunnel ventilation, signalling, fire fighting and automation, which are needed to meet high safety requirements due to heavy traffic in the undivided two-lane tunnel, were provided by siemens. the dranaz tunnel was opened to traffic in presence of prime minister recep tayyip erdoğan on february 14, 2009.