Amtrak passenger trains arrived on schedule 70 percent of the time in 1988, according to the railroad. The 1987 on-time percentage was a notch better-71 percent. In 1986 it was 74 percent. However, in 1985 Amtrak trains were on time 81 percent of the time, and in the years preceding that the rate was around 80 percent.

Amtrak's maximum tolerance of on-time arrival is 30 minutes for trains going more than 551 miles. The minimum allowance is five minutes, for trains traveling up to 150 miles.The dip in performance last year was the result of increasing ridership, said John Jacobsen, a public relations official, who said that more ridership means longer boarding and unloading time. He also cited a shortage of backup equipment in cases of mechanical difficulty.

In 1988, short-distance runs-of up to 600 miles-outside the Northeast Corridor had the best record; on-time performance was 79 percent. At the opposite end of the scale were trains traveling long distances: on-time performance in that category was 61 percent.