NEW DELHI: Describing the Mumbai-Goa national highway as "death trap", road transport and highways minister Nitin Gadkari on Monday said it will be soon converted into a four-lane concrete road at the cost of Rs 4,500-5,000 crore.Replying to a supplementary during question hour, he said though there were some problems regarding land acquisition, it would be sorted out in the next three months."The stretch has become a death trap. So we have decided to convert it into a four-lane concrete road," Gadkari said, adding it would require Rs 4,500-5,000 in doing that.Widening of the stretch would reduce accidents, he said.To another question, Gadkari said around five lakh road accidents take place each year and the casualties relating to these accidents reach up to 1.5 lakh.