[JasonB]

Jason, thank you for such a fast answer! First, it could happen in diferent tracks and if I apply some pressure or force to the area of the track which connects with the other track, then the car starts moving. It appears like if when I begin to extend and make a larger track, the issue accentuates. It also appears like if the problem is related to a loss of electricity flow in the track "rails". Thank you for all the help I can get!!!

It sounds like you might have loose connections at the track joints.

Pfuetze's advice above is probably the way to go.