State Highway 1, which is a motorway at this point, passes by the west of the town. For many years, State Highway 1 ran through the town along the main street, but the Northern Motorway was built to replace it some years ago. The Main North Line railway runs through Kaiapoi, and the town once served as the junction for the Eyreton Branch, which provided rail access to communities west of Kaiapoi such as West Eyreton (though it ran to the north of Eyreton itself). This branch line opened in 1875 and closed fully by April 1965.
The river used to have a port before the construction of the Waimakariri River bridge, and was an important point for the transport of goods to and from Christchurch. Bucking the trend of river ports dying off in the middle of the 20th century, the port actually reopened for a decade between 1958 and 1967, to allow smaller ships to bypass the congested Lyttelton wharves.
At one stage, a walnut tree on one resident's property was so large, it was used to act as a landmark for pilots approaching Christchurch International Airport to get their bearings, before being cut down by the owner and his sons
