Some short standard Brio tracks which were needed by my son.
I expect to add more tracks here in the future. If you can not wait, then just use the .blend-file as a boilerplate, and stretch away ...
The attached slic3r_config.ini gives fast prints with low, but sufficient, quality. One perimeter, one solid layer, 0.2 infill, and 0.4mm layer thickness.
Use the slic3r_config.ini, or read the parameters. Better still, find some better or more suitable parameters. CAUTION! : Mind the Z-offset; not for your printer!