Characterise changes to rail transit operation on the study section of the Southern Main Line and Interstate Line between datum $0\mathrm{.}565$km and $4\mathrm{.}421$km $,$

focusing on accommodation of train services by passenger line in the weekday a$.$m$.$ peak, daytime off$-$peak, and p$.$m$.$ peak periods.

Consider aspects such as operations at terminus station$/$s$,$ number of tracks in each direction, crossing loops, crossovers, and crossing of paths.

$($Hint: Assume that the new Park Road line enters study section on Southern Main Line Up$,$ crosses over to Interstate Line, crosses over to Southern Main Line Loop, terminates on Southern Main Line Loop at Park Road, returns on Southern Main Line Down.$)$