I wouldn't say there's a strict KPI. When there are a lot of other factors.... You also have some convenience. On the train, you can work. You don't have to control your car, take the wheel or whatever. There is no clear KPI, but you definitely have to be faster. That's all I can say. If you look at the high-speed rail systems in Europe, it's roughly between 10% and 40%.
On February 13th, 2024. See this statement in context.