# Understanding superelevation rollover

You can add superelevation values when defining an RXL road.

## Outside of curve (high side)

As shown below, the superelevation rollover value is the maximum algebraic difference in cross slope (3) between the carriageway or travel lane (1) where the carriageway is adjusted by superelevation and the shoulder (2) which is not adjusted by superelevation. If the station being staked includes superelevation that results in the difference in cross slope exceeding the specified maximum, the slope defining the shoulder is adjusted so that the algebraic difference in slope is not exceeded.

## Inside of curve (low side)

For the inside of a superelevated curve, the shoulder (2) uses its design value unless that value is less than the slope value of the superelevated carriageway (1). In that case, the superelevated value for the carriageway is used for the shoulder. This behavior happens only if you specified a maximum superelevation rollover value.