The "extra simple walker" based on http://www.instructables.com/id/Extra-simple-walking-mechanism/ is not relevant enough for its own wikipedia article.

However: Beeing very simple makes it a good base line. The mechanism is by no mean ideal, but it is possible to build a vehicle around it.

The basic mechanism looks like this:

• 
  Base Mechanism

The vehicle looks like this:

• 
  Dimensions

So. lets look at the walking vehicle:

• 
  Walking robot

The green base plate is going up and down a lot. It would be a very hard ride, just from the up and down. Not as easy to see is the speed variation:

• 
  Speed

Now take a very close look at the animation:

• 
  with speed plotted

Gallery

• 
  Base Mechanism
• 
  Robot hold still
• 
  Walking robot
• 
  with speed plotted
• 
  3D-Animation