Persons authorized to construct and maintain a railroad as provided in RSA 245:2 may locate and lay out the road in its entire course at one time, or in parts at different and successive times, as they shall deem conducive to the interests of all concerned.
RSA 245:5
CS 150:21. GS 146:4. GL 160:4. PS 158:5. PL 248 :5. RL 298:5.