sentences:  However the planned flyover was abandoned in favour of moving the existing level crossing some 250 metres to the west of its original position underneath the Hamilton Interchange approaches.In 2008 construction began on the Perth Arena Bus Bridge, crossing Roes Street, which would offer a similar route to the abandoned Fitzgerald Street option.When the project commenced, it was believed that Westrail, then responsible for the provision and management of metropolitan rail transport for Transperth, would not have enough rolling stock to operate the new line.