One reason is that trains are hugely more efficient in terms of passengers carried per operator:
On a bus carrying 50 people, the driver is a much more significant portion of the cost than a driver and a conductor on a train carrying 2000 people.
So even though it's much easier to automate a train, there's less incentive to do so, and doing so still requires investment. It'll slowly happen anyway, of course, but there's no real rush.
On a bus carrying 50 people, the driver is a much more significant portion of the cost than a driver and a conductor on a train carrying 2000 people.
So even though it's much easier to automate a train, there's less incentive to do so, and doing so still requires investment. It'll slowly happen anyway, of course, but there's no real rush.