That's the first stage of any rail project - in California they have literally build hundreds of these unconnected bridges, viaducts and embankments. Same thing

That's the first stage of any rail project - in California they have literally build hundreds of these unconnected bridges, viaducts and embankments. Same thing with HS2 in the UK. Connecting them all up with rails and catenary is the (relatively) cheap, quick and easy bit, and it's done at the end - it's exactly all these structures (and the stations, which will likely be the next phase) that take all the time and money.