 The main stumbling blocks, apart from costs, appears to be the Johor-Singapore Causeway which Mahathir had once hoped to replace with a 'scenic bridge'.There were doubts about the capacity of such a curved bridge to carry a rail line and YTL having to use KTM land which runs from Woodlands to Keppel.Redevelopment of this land in Singapore could probably help fund the proposed railway if the various parties involved each had a stake in each other.