RTD bus travel disincentive

I found out today that when one uses prepaid bus tickets that one can use only one at a time. The regional passes have a value of $5. If the fare is $10, one cannot use two tickets. I suppose the reason is that the ticket is purchased at a discount. Let’s say the price is $4.50. RTD must want to limit the discount per trip. I think a percentage discount makes most sense. That, and also that one does not need to manage exact cash change, would be incentives. Instead, RTD creates a disincentive to alternative transportation. This is another example of public institutions driven by private capitalist ideas and the resulting irrational outcome.