[badrunner]

I don't know the specifics about the trainset for Brightline West but it's reported to go up to 186mph (through flat desert), and the journey from Rancho Cucomonga to Las Vegas is expected to take about two hours. You're right though, it might not be the train. The track itself could still impose a speed limit.

There should be a separate thread for Brightline West on here once contruction starts and we start getting regular updates.