Most Shinkansen trains operate at speeds of about 500 kilometers per hour (200 to 275 miles per hour). As new technologies are developed and instituted, future trains may achieve even greater velocities.

The term "bullet train" (originally from the Japanese Shinkansen) is generally applied to high-speed rail systems that operate at speeds of at least 250 km/h (155 mph) on lines specially built for high speed. According to international standards used in 2026, a train can also be considered "high-speed" if it reaches roughly 200 km/h (124 mph) on existing lines that have been specially upgraded to handle such velocity. In China, the world's leader in HSR, many trains regularly cruise at 350 km/h (217 mph). In the United States, the definition is slightly more flexible; the Acela Express is considered high-speed despite only hitting 150 mph on small sections of track. The "bullet" moniker refers more to the aerodynamic shape and the dedicated, grade-separated tracks that allow these trains to maintain high speeds without interference from road traffic or slower freight trains. To be a true "bullet train" experience in 2026, the system must typically combine these high speeds with advanced signaling, automated braking, and "tilting" technology to manage curves comfortably for passengers.