It doesn't matter if have 116 Straight tracks, 64 Curve tracks, or even 5 stations. If you don't have these pieces, your layout is mediocre. Switchtracks are important if you want to build a complex, dynamic railroad. without these, all your trains are required to run in one direction, whereas with them, you can have multiple Passenger Lines and Frieght lines, with multidirectional trains and many sidings for the extra rolling stock. I would assume the extra curves are for more advanced builders (No, not the ones who cut up and modify their peices), who can use the extra curves to intigrate the switch into a curve, or elsewhere on their layout. in any case, this set is MANDATORY if you want a nice layout.