As with the rest of the Auto Combat line, there are many printout options with varying degrees of damage and wear (e.g. we use two printed sets; a "nice" set for the Auto Combat Arena, and a "junk" set for our desert table all covered with grime and graffiti that are layer options in the PDFs).
When weighted with ballast as suggested (I used sand) they have a substantial weight and don't get bumped around at all.
Also worth mentioning: The Auto Combat Arena texture blends nicely with these; they look great together.
As mentioned in another review, the one negative is that the directional/arrow barriers have an untextured bottom, forcing you to either print out multiple copies of each, or hack together a "flippable" one yourself. If you switch your track layout a lot, you frequently run out of the necessary direction.
Silly tip: You can print these out with increasing degrees of battle damage and lay them out so that early portions of a race have less damage than the later... makes for a cool little narrative, especially as drivers pass Gate 1 and weapons unlock...