Explanation:

=> Prime Minister Narendra Modi laid the foundation stone of the Delhi-Dehradun Economic Corridor (Eastern Peripheral Expressway Junction to Dehradun), Child Friendly City Project Dehradun, in Dehradun, Uttarakhand. Also inaugurated the state-of-the-art Perfume and Fragrance Laboratory (Centre for Aromatic Plants) at Doon.

=> The total length of the Delhi-Dehradun Expressway will be 175 km. The highway will be built at a cost of about Rs 8,600 crore. The highway is being built to encourage economic activities and encourage investment.