India needs a minimum investment of $72.3bn to carry out its plan to build a 18,650km national expressway, according to the project’s draft master plan.

The report, which has been submitted to the government by India’s transport ministry, says it will cost $4m per km to build a four-lane expressway and $5.5m for a six-lane expressway.

This is nearly 2-10 times more compared with $0.5m to $2m per km needed to build a national highway.

The report has suggested building 18,637km of expressways instead of 15,600km proposed in July this year.