The Photonic Railway is proposed to overcome the limit of the current propulsion technology based on conventional rocketry for interstellar flight and to potentially open a new space era. The photonic railway, which is a permanent energy-efficient transportation structure based on the Beamed-Laser Propulsion (BLP) by Forward and the Photonic Laser Thruster (PLT) by the author, is proposed to enable such routine interstellar commutes via proposed Space Trains. It is shown here that the developmental pathway towards the interstellar flight demands not only technological breakthroughs, but consistent long-term world-scale economic interest and investment. Such interest and investment will only result from positive financial returns from routine interstellar commutes that can transport highly valuable commodities in a profitable manner. A four-phased evolutionary developmental pathway towards the interstellar Photonic Railway is proposed. Each phase poses evolutionary, yet daunting, technological and financial challenges that need to be overcome within each time frame of 20 Â 30 years, and is projected to generate multitudes of applications that would lead to sustainable reinvestment into its development. If successfully developed, the Photonic Railway would bring about a quantum leap in the human economic and social interests in space from explorations to terraforming, mining, colonization, and permanent habitation in exoplanets.