Occasionally the fields would fold in on themselves and form a deadly sphere that would travel through the system until it eventually imploded, killing everything caught in it. This was known as a force sphere.
There were two methods to boarding a chute. The recommended way was a chute station. These stations were located all over Metru Nui. Here the chute flow would slow down enough to where boarding is safe.
The other method, "Chute Jumping", was illegal, although it was still done by some of the more daring Matoran. Chute Jumping involved leaping onto a chute during the split-seconds that the magnetic energy wavers, passing right through the outer layer of force and into the chute itself. There were two reasons why this was risky: First, if the jump was not timed right, the jumper could smack into the outer layer hard and possibly fall off the Chute and plunge to the ground. Second, there was the chance that the jumper could collide with cargo or passengers. This was attempted successfully by Vakama, Nokama and Matau as they were escaping from Nidhiki and Krekka.
The Le-Matoran who ran the system feared that reversing the flow could cause the entire city-wide system to destabilize. Nidhiki once forced Kongu to do just that, but it had little, if any, negative effects on the system.