Wellington Urban Motorway

Wellington Urban Motorway
State Highway 1
The Wellington Urban Motorway in 1994, looking north out of Wellington. The motorway shares a narrow stretch of land with the Hutt Road, the North Island Main Trunk railway and the Wairarapa Line.
Route information
Maintained by NZ Transport Agency
Length:	7 km (4 mi)
Existed:	1969 – present
History:	Completed in 2007
Major junctions
North end:	Ngauranga Ngauranga Interchange
	Exit 1068 Ngauranga Interchange State Highway 2
South end:	Te Aro Karo Drive and Vivian Street
Location
Primary destinations:	Ngauranga, Kaiwharawhara, Thorndon, Kelburn, Te Aro, Wellington CBD, Waterfront
Highway system
New Zealand state highways Motorways and expressways List Unused

The Wellington Urban Motorway, part of SH 1, is the major road into and out of Wellington, New Zealand. It is 7 km long, ranges from three to seven lanes wide, and extends from the base of the Ngauranga Gorge into the Wellington CBD.

From the Ngauranga Interchange (State Highways 1 & 2), the motorway travels south across a narrow piece of land alongside the Wairarapa and North Island Main Trunk railway lines. After passing through the suburb of Kaiwharawhara, the motorway travels across the 1335m long Thorndon overbridges, the longest bridges in the North Island, before entering the suburb of Thorndon. Shortly after it enters the Terrace Tunnel before terminating at Vivian Street in Wellington City.

The concept for the Wellington Urban Motorway first arose from the De Leuw Cather report on Wellington urban transport in 1963 which proposed a "foothills motorway" to be built from Ngauranga to the Mount Victoria Tunnel. The alignment and scale of the motorway between Ngauranga and the Bowen Street overbridge as built very closely matches the original proposal, with the one exception that the proposed interchange at Ngaio Gorge (with on and off ramps over the railway to Kaiwharawhara) was never completed, although the stumps of a southbound on ramp and northbound on and off ramps remain visible today broadly parallel to Kaiwharawhara railway station. Beyond the Tinakori Road and Hawkestone Street on/off ramps going south, the motorway is a considerably scaled down concept from what was initially proposed.

The first phase of the motorway was opened between Ngauranga and Aotea Quay in 1969 as part of State Highway 2, relieving the chronically congested traffic signal controlled intersection at the base of the Ngauranga Gorge which endured peak time delays of several kilometres at AM and PM peaks. The motorway was extended in phases as far as Hawkestone Street/Tinakori Road by 1974. However, its last major extension was completed in 1978, with the construction of the Terrace Tunnel and the termination of the motorway at Ghuznee/Vivian Street.