This Technical Report provides general, informative guidance for the integration of safety critical and time critical warning signals (signals which, if ignored even briefly, could result in bodily harm to the occupant(s) of the vehicle and/or to other road users) into existing in-vehicle messages presented to a driver. Integration of non-critical signals are outside the scope of this Technical Report, except to confirm that they do not affect the driver’s comprehension of safety and time critical signals. This Technical Report provides: 1) possible approaches for determining if integration is necessary to mitigate the possibility that signals from one or more vehicle system may degrade the driver's comprehension of, or response to, safety critical warning signals from another system(s); and 2) a discussion of possible methods for assessing potential integration conflicts. It does not provide prescriptive guidance in how to design an integrated warning HMI