If multiple stops is not viable, when entering a 2nd stop and receiving the message that only one stop is allowed, if an option could be provided at this time allowing the user to remove the 1st stop and use the 2nd, or to disregard the 2nd stop, leaving the 1st. If the 2nd stop is preferred, this would be easier than having to go back and remove the 1st stop and then reenter the 2nd stop all over again.
If multiple stops is not viable, when entering a 2nd stop and receiving the message that only one stop is allowed, if an option could be provided at this time allowing the user to remove the 1st stop and use the 2nd, or to disregard the 2nd stop, leaving the 1st. If the 2nd stop is preferred, this would be easier than having to go back and remove the 1st stop and then reenter the 2nd stop all over again.