Acela trains are the fastest in the Americas, reaching 150–160 miles per hour (240–260 km/h) (qualifying as high-speed rail), but only for approximately 40 miles (64 km) of the 457-mile (735 km) route.

That has to be the slowest high-speed rail in the world. 260km/h is not even that fast and it only reaches this speed for couple minutes.