East Japan Railway Co. is planning a change that could affect more than 3.5 million people a day-although they might not notice it.

Trains on the Yamanote Line, Tokyo's main artery for 80 years, next year will complete the loop in central Tokyo in 58 to 59 minutes, breaking the 60-minute barrier, company officials said.

A digitized automatic train control (ATC) and new cars will shave three to four minutes off the time it now takes the trains to circle the 34.5-kilometer route.

In addition, Yamanote trains will hold more passengers and allow for a smoother ride.

The Yamanote Line, which now carries 3.55 million passengers a day, or 1.3 billion a year, started operating between Shinagawa and Akabane stations in 1885. It became a loop line in 1925.

Trains currently run every two minutes during morning and evening rush hours and every three to four minutes during the daytime.

When the loop was formed, it took trains 72 minutes to complete the route. By 1939, the operator, then Japanese National Railways, cut the travel time to 64 minutes. But postwar confusion and a surge in passengers pushed the time back to 75 minutes in 1946.

In 1988, new cars with better control capabilities shortened the overall time to 62 minutes.

But breaking the hour barrier had to wait for new ATC technology now being installed.

ATC automatically applies a brake when a train exceeds certain speeds. Digitizing the system will reduce jolts, the officials said.

It also allows shorter train intervals, allowing more hourly train runs, theoretically from the current 24 to 26.

JR East is replacing old cars with a new E-231 model that is wider and can carry more passengers. About 70 percent of the line's 600 cars have already been replaced.(IHT/Asahi: January 25,2005)