Stavropoulos gives deliver (up), turn in/over, give in/up/over, hand over, yield up, which looks like a rich choice. None of these is the best choice, however. hand over might be used, but in the more specific and technical context of one contractor finishing what they were supposed to do. Here however, the contractors are not mentioned. And here the writer is talking about the "final" act of handing over, so that the trains can run and the public can use them. What is the very simple English verb which is generally used in this situation? If you cannot think of it in 2 minutes, then click here for the answer.