The Puzzled Driver

The odometer of the family car shows 15,951 miles. The driver noticed that this number is palindromic: it reads the same backward as forward.

“Curious,” the driver said to himself. “It will be a long time before that happens again.”

But 2 hours later, the odometer showed a new palindromic number.

How fast was the car traveling in those 2 hours?

Puzzle provided by Kordemsky: The Moscow Puzzles (Dover)