The bank indicator must be adjusted to the zero reading before test runs are conducted. This must be done with the car straddling the center line of the pavement on a tangent section to give the effect of a flat level surface and the driver and recorder in the same position in which they will ride during the test runs.

It is essential that the driver and recorder be in the same position when the bank indicator is set to the zero reading as they will be when test runs are made, because a shift in the load is reflected in a change of the indicator reading.