The "rearward amplification" value means `_________`.

A How easily you can roll the last trailer, i.e. 3.0 = 3 times as likely.

explanation

Rearward amplification of 2.0 on the chart means that the rear trailer is twice as likely to turn over as the tractor. You can see that triples have a rearward amplification of 3.5. This means you can roll the last trailer of triples 3.5 times as easily as a 5-axle tractor-semi.