Haha, it seems they missed the more obvious solution: build a second story rail (with a middle rail so you can even split up or redirect workloads) and move lig

Haha, it seems they missed the more obvious solution: build a second story rail (with a middle rail so you can even split up or redirect workloads) and move lighter, smaller goods faster. You can now optimize for transportation of goods more valuable or time sensitive but less bulky, move them faster, and add capacity to your system, all at the same time. All on exactly the same land without interrupting existing rail. And since it's smaller and higher they could expand or reroute over properties where before it would've been too difficult. Low tunnels and bridges would of course be an issue; some you could just go above or around, others maybe not at all. Still, there may be routes where it makes sense.