go to your local tru or poolorama or any other place that would sell pool stuff and get some of those pool noodles. they bend and curve and are soft and tall so you could lay them on the ground and tape em down in the way you want for a cool safe track and its cheap. for more easier cheaper ways figure out a way to cut them down the midle like a hotdog bun then lay them on the ground flat side down in the shape you want and thats even beter
i duno if it was any help but it was just a crazy idea i had thought of