Vehicle system and vehicle control method

A vehicle system and vehicle control method enabling notifications to be made for smoothing traffic involving a host vehicle, that is, a vehicle system having a processor for judging a running state of a host vehicle, wherein in case of the processor judges that a second running state in which the host vehicle will change in behavior compared with a first running state in which the host vehicle or other vehicles present in the surroundings of the host vehicle are currently running will occur due to a predetermined reason, alerts the outside of the alert content including the predetermined reason.