Gwt-maps driving directions, tweaking?

[John]

I have a situation, where I ask for driving directions from A to B, thus:

A B

C

Google, in their wisdom and preference for better-grade highways,
routes me through C. Locals all know that the straight shot, from A
to B is waaaay better.

So I have been trying to force Google gwt-maps to NOT go through C.

The best(?) workaround so far is to create a waypoint D, thus:

A D B

C

It sort of works, but the driving directions have a stupid,
meaningless waypoint stuck into them.

I threw away all the Gwt-maps directions panel and coded the whole
mess, and it does get me exactly the right "looking" directions panel
(without the extra balloon), BUT...the directions still include a
meaningless stop.

I can't believe that there isn't a better workaround. For instance,
if the road through C was washed out for six months, isn't there a way
of "blocking" that route, and forcing google maps to seek an
alternate?

Maybe I'm missing something obvious (I hope).

John