MINECIRCUIT EXP is the circuit simulator.
(You can use without registration.)

Let's make the original circuit by combining parts freely.
It is using Mini 4WD Japan Cup Junior Circuit.

[function]
*course add
*course delete
*course move
*course group move
*course rotate
*circuit zoom
*circuit save
*circuit delete
*circuit name edit
*circuit copy

https://youtu.be/fArhojE6VxY