The Road ministry has completed safety audit of 1.6 lakh bridges in the country. Road Transport and Highways Minister Nitin Gadkari said, 147 bridges were found to be unsafe during the audit. <br/><br/>The government had launched an Integrated Bridge Management System to create data of all bridges and culverts in the country to avert mishaps. Mr Gadkari said, 23 structures were found to be more than 100 years of age. <br/><br/>He said, new technologies using nano, laser and sensor are being introduced for real-time monitoring of bridges, while radars, infra ray drones will be used for its inspection.