Trimble has announced that its positioning technologies are being used to help speed construction of the US$1.7 billion Hangzhou Bay Transoceanic Bridge in China. Contractor China Railway Bridge Bureau Group is using Trimble global positioning systems, digital auto levels and software on the 36 km six-lane bridge. Trimble said that the distances are so great that conventional survey systems would either reduce the accuracy or would require extra control stations. Accuracy is improved for long distances by using the GPS systems with a reference station for differential corrections, said Trimble, enhancing the contractor's productivity.