These Systemwide travel vouchers are a unique voucher in that they are not supposed to be combinable with other Systemwide vouchers. However, they have the major benefit of retaining their residual ticket value due to a ticket price lower than the value of the voucher, so you do not have to worry about making sure the fare basis of the ticket is equal or higher to the ticket's cost. If a ticket costs $280 and the voucher's value is $400, then one would receive another residual vlaue voucher of $120.