"Like other reviews have said, this set is not designed to work with sets like "Number Train" (10847), "Mickey & Minnie Birthday Parade" (10597), "Toy Story Train" (10894), or other sets that have the larger wheels (often red or yellow) on the sides of 2x6 bricks. If you have either the "Steam Train" (10874) or "Cargo Train" sets (10875) that come with battery powered trains with skinny wheels then this set will work great and allows for must more interesting track design."
"Adding the switch track pieces to the "Steam Train" set (10874) along with the bunch of extra curves makes the track layout so much more interesting than the default circle. Highly recommend!"