In this model Roman demo 001.3dm I took away all rotational data, leaving only the ‘pause’ at the corner of the path.
In the KeyframeEditor you can see the setting of the Constraint parameter.
For keyframe 0 the parameter is set to 0.000 hence bringing the cube at the start of the path. In keyframe 99 the parameter is 1.000 hence taking the cube at the end of the path.
To realize the pause I created keyframes 40 and 55 (obviously you can choose whatever number you like) and entered in both the value of 0.323.
There are various techniques to find out the value needed in order to get the cube at the corner of the path, but you can also simply use by trial and error.
In order to get have the cube stable during the pause it is necessary that the value in both keyframes are identical, and that the Easing is set to Automatic (as it is by default). If not the cube would slightly move hence and forth during the pause.
More questions? Shoot.