actually, that's an episode of the original outer limits called PREMONITION.
from imdb: When a test pilot crashes in his experimental X-15 plane, he and his wife discover they are in a reality where time has slowed down almost to a standstill. Returning to the airbase, they are horrified to see their daughter standing in the path of a moving truck and they seem to be unable to prevent her death.
Episode where child, i think, was going to be hit by a car. Time began to move slowly except main character was in real time and had to try and stop car from hitting child. I think he tied seat belt... more