If the direction form text in the infowindow is too light (or doesn't appear at all because it is white against a white background) or you want to customize it, add a class "mapdirform" to your template.css.css file. This class will effect the <form> of the direction form.

You can do this by going to Site/Template Manager/site Templates in the Admin backend, then "Edit CSS" for the template you are using.

Here is an example you can add:

.mapdirform  {
      font-family: Arial,  Helvetica, sans-serif;
      font-size:  10px;
      color:  #000000;
}

This documentation is provided by Jack Breaks.

If you want to change the style of the directions of google maps api version 3 then you have the following classes available: .adp-legal, .adp-placemark, .adp-directions and .adp-summary.

Foe example to show only the summary with the total distance and dureation, add this to your template css:

.adp-legal,
.adp-placemark,
.adp-directions
{
      display: none;
}