Warning lights came on while traveling.

The most common thing is the inverter water pump. You can look and see if the coolant in the inverter is moving around. I'm sure there are many threads on how to do this. Other then that we will need diagnostic codes.

 

What other warning lights appeared besides the red triangle master warning light?

If that is the only light that came on, then it is hard to say what the problem is and it is doubtful that any DTC were logged. I suggest you start by checking all engine compartment fluid levels as well as your fuel tank level.

 

I used to get the master warning light from a loose connection in the wiring harness at the main battery. jiggling the wires would get rid of the light. Dealer did something to tighten that connection and it hasn't happened in a long time.