A performance review of ministers that was carried out ahead of Sunday's mega reshuffle helped. Mr Gadkari was in the list of ministers who had aced their reviews.
This time, the ministers' performance was classified as "positive" or "negative", there was no other grading. Mr Gadkari has topped the performance charts in the reviews carried out by PM Modi in the past too. Mr Gadkari too wasn't keen to take the additional responsibility.
The ministers were not only judged on the performance of their departments but also how proactively and efficiently they set upon tasks assigned by the party to take schemes and achievements to the masses.
Rail Minister Suresh Prabhu had first hinted about a change in the rail ministry last month when he owned moral responsibility for a series of train accidents and offered to quit.
The minister later said PM Modi had asked him to wait. It was the first confirmation that the much-delayed cabinet reshuffle was round the corner. But rather than see Mr Prabhu exit his team, sources said, PM Modi was keen to give the rail minister an important assignment, possibly the defence ministry.