Whenever the commission shall find, after a hearing had on its own motion or upon complaint, that repairs or improvements to, or changes in, any telecommunications line ought reasonably be made, or that any additions or extensions should reasonably be made thereto in order to promote the security or convenience of the public or employees, or in order to secure adequate service or facilities for telecommunications communications, the commission shall make and serve an order directing that such repairs, improvements, changes, additions or extensions be made in the manner to be specified therein.