By Poppy Clark of 
The shortest state highway in New Zealand is 900m and located in the South Canterbury town of Timaru. Photo: JOHN BISSET/STUFF
Nestled in a South Canterbury township just off New Zealand's longest road - State Highway 1 (SH1) - lies a stubby, looping road of "nationally strategic purpose".
At just 900m, Timaru's State Highway 78 (SH78), also known as Port Loop Rd, is the country's shortest state highway.
Having opened in 1972, SH78 begins off SH1, over the South Island Main Trunk Railway in Timaru and then turns anti-clockwise around and passes itself before entering Ritchie St, which leads straight to Timaru's PrimePort.
This looping route means it is believed to be the only state highway to cross over itself, without including motorways on and off ramps.
But why is it a highway?
According to Waka Kotahi, state highways are roads in New Zealand that are used deliberately to move people and goods throughout the whole country.
Its website says that state highways "form a nationally strategic purpose" and are a Crown asset managed on behalf of central government.
The term state highway is different from local roads which are built and maintained by local authorities like councils.
A Waka Kotahi spokesperson said SH78 met the threshold of a state highway because of the Timaru PrimePort that the road leads to.
"It is a significant freight route because the port is a strategic asset to the government," they said.
"The total length of highways in New Zealand is 11,000km and SH78 makes up 0.008%," the Waka Kotahi spokesperson said.
To put the fleeting 900m highway into perspective, Auckland's Harbour Bridge is 1020m, Christchurch's Lyttelton tunnel is 1970m and the Rakaia River Bridge on SH1 is 1757m long.
At the end of last year, a shared path trial began on SH78/Port Loop Rd by the Timaru District Council which looked at the balance between safety and amenity for pedestrians, runners, cyclists, scooters, and other active modes to move between Caroline Bay, Timaru Port, the coastal trail network, and the CBD.
In second place for shortest state highway is SH44, at 5.2km short it runs straights through the North Island city of New Plymouth.
This story was first published by Stuff
