Copying object along the path - Caterpillar tracks effect in Illustrator

[oldbunyip]

Is it possible at all to copy/distribute an object along the path in Illustrator 10 or CS? Doing this along a perfect circle is quite easy, but this time I have the rectangle shape with rounded corners. I need this to create a caterpillar tracks for some illustration. Some people advise that Blend tool and art brush can help in this case. Art brush (made out from small squares) can be partially helpful, although the final effect is far from perfect. Couldn't figure it out when it comes to Blend tool.
Cheers