Today, more than 11,000 vehicles cross the two lane bridge each day.
The two lane bridge has a span of 1,360 feet and was opened in 1965, built at a cost of $746,000.
In 1838 the single lane bridge was widened to two lanes.
The two lane bridge is 288m long and 7.35m wide.
The island residential area is still linked to the mainland by its original, single lane bridge.
On average 10,000 vehicles crossed the narrow, single lane bridge daily.
New Zealand, due to its low traffic density, has had many single lane bridges.
There are several more one lane bridges, blind curves and hills.
The fourth would replace all three spans with an eight lane bridge.
In 1955 the islands were connected by a one lane bridge, as it remains today.