A common configuration in busy locations on high speed lines is a pair of island platforms , with slower trains diverging from the main line ( or using a separate level on the railway 's right - of - way ) .
The main line tracks remain straight .
A common configuration in busy locations on high speed lines is a pair of island platforms , with slower trains diverging from the main line ( or using a separate level on the railway 's right - of - way ) so that the main line tracks remain straight .