I've seen these before. Pretty much the same as an ASH time trial - Just much prettier!
We do things very similar. I'll try to find a video.
Not many good ones but heres two. There are different obstacles every time. Generally the first obstacle is a gate and you have to walk to the gate and you can go fast from there on - Sometimes a walk or trot section at the end as well.
<object width="480" height="385"><param name="movie" value="
http://www.youtube.com/v/IYN-HTz2RfM...</param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="
http://www.youtube.com/v/IYN-HTz2RfM...en_US&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>
<object width="480" height="385"><param name="movie" value="
http://www.youtube.com/v/7Lw225dERdw...</param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="
http://www.youtube.com/v/7Lw225dERdw...en_US&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>