Layout PLanning Software

I am looking for a program to help with planning a layout for Lionel Tubular track> Can some one please recommend a product and tell me where I can get it?

Thanks

I have used RR-TRACK for Windows by R&S Enterprises. Their software is not the easiest to learn, but it works for many scales. Below is my layout design that was done with the program.

You can see their web site at:
http://www.rrtrack.com/

Atlas has a free software for download, but of course it is set up for Atlas Track.