Running control apparatus for vehicles and alarm apparatus for vehicles

A running control apparatus for vehicles, comprising:

• relative acceleration detecting means for detecting a relative acceleration between a subject vehicle and an object;
• judging means for judging whether the subject vehicle and the object relatively approach each other at the relative acceleration detected by the relative acceleration detecting means not less than a predetermined value of relative acceleration;
• and
• control means for controlling the subject vehicle velocity such that the relative acceleration for which a direction to make a relative approach of the subject vehicle and the object positive is not more than a predetermined target value of relative acceleration when the judging means judges that the subject vehicle and the object relatively approach each other at the relative acceleration not less than the predetermined value of relative acceleration, wherein said relative acceleration detecting means includes a radar means for obtaining at least one of the distance and the relative speed therebetween, and the relative acceleration is obtained by differentiating the obtained one of the distance and the relative speed thereof.