As readers know, the line from the north through Waikanae as far as the south side of the bridge over the old SH1 remains single track. When a comuter train is scheduled to be at the station platform, it needs to move to a refuge siding north of the station (there is also a storage siding in the location) to allow the freight trains to pass.
An obvious step that needs to be done to alleviate congestion is to double track the whole line between the overbridge south of the river and Otaki.
Bridges are expensive, however, and big cost was the reason that wasn’t done at the time of electrification to Waikanae. But that was only delaying the inevitable — when will it happen?