New Zealand State Highway 21

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

State Highway 21 NZ.svg

State Highway 21
Route information
Maintained by NZ Transport Agency
Length 6.7 km (4.2 mi)
Major junctions
Northeast end SH 1 at Tamahere
  Hamilton Airport
Mystery Creek
Southwest end SH 3 at Ohaupo
Highway system
SH 20 SH 22

State Highway 21 (SH 21) is a short 6.7 kilometre stretch of highway in the North Island of New Zealand. It links State Highway 1, Waikato Expressway at Tamahere and State Highway 3 at Ohaupo. Its main destination is Hamilton Airport and Mystery Creek, where the National Agricultural Fieldays are held.

SH 21 was gazetted as a brand new state highway designation in 1997.[1]


State Highway 21 is actually 120km south of where the number is supposed to be when considering the general pattern of assigning increasing state highway numbers in a north-south direction; in reality, it should lie somewhere in South Auckland. This southern placement makes SH 21 the second-most southern SH 2x highway, after SH 28.

At the exit to Hamilton Airport, State Highway 21 used to show Hamilton to be in both directions (i.e. left to Hamilton and Rotorua, right to Hamilton and Waitomo Caves), and was possibly the only place in the State Highway network in which this happened (the actual difference between turning left and turning right is only 800 metres). In 2015 the signs were updated to show Hamilton to the left, and the route to the right is now on a separate sign reading "Hamilton via State Highway 3".[citation needed]

Major intersections[edit]

Territorial authority Location km Destinations Notes
Waikato District Tamahere 0 SH 1 south (Waikato Expressway)/Thermal Explorer Highway – Rotorua
SH 1 north (Waikato Expressway)/Thermal Explorer Highway – Hamilton
SH 21 begins
2 Narrows Bridge (Waikato River)
Waipa District
Mystery Creek 5 Hamilton Airport
Mystery Creek Road – Mystery Creek Events Centre
Rukuhia 7 SH 3 south – Waitomo Caves, New Plymouth
SH 3 north – Hamilton
SH 21 ends

Narrows Bridge[edit]

The first bridge opened on 12 February 1879,[2] costing £999 17s 4d, with a £300 government subsidy,[3] £90 each from Waipa and Waikato County Councils and the rest paid by donations.[4][5] It lasted until blown up in 1940.[6]

Its 49.5 m (162 ft)[7] reinforced concrete replacement,[8] supported by a 31 m (102 ft)[7] steel arch,[8] opened in December 1939.[9] It is 1.78 km (1.11 mi) from the Tamahere end of SH21[10] with a road width of 20 ft (6.1 m) wide, plus a 5 ft (1.5 m) footpath, which cost £5,660[11] (£3,000 from government and the rest shared by the counties)[12] and was designed by Jones and Adams (see also Tuakau Bridge).[13] It was given a NZHPT Category 2 historic listing in 1985.[14] The river banks were soil nailed in 2010 to protect the foundations.[15] The effect of the works can be seen in the AADT figures - 2008 (5087), 2009 (5288), 2010 (4972), 2011 (4921), 2012 (4910), 2013 (4892), 2014 (5391), 2015 (5551).[16]

See also[edit]


  1. ^ "Revoking Sections of State Highways Declaring New Sections of State Highway". New Zealand Gazette. 26 June 1997. Retrieved 5 July 2016. 
  2. ^ "THIS DAY. (Auckland Star, 1879-02-13)". National Library of New Zealand. Retrieved 2017-06-26. 
  3. ^ "The Waikato Times. SATURDAY, FEBRUARY 8, 1879. (Waikato Times, 1879-02-08)". National Library of New Zealand. Retrieved 2017-06-26. 
  4. ^ "WAIKATO COUNTY COUNCIL (Waikato Times, 1879-09-09)". National Library of New Zealand. Retrieved 2017-06-26. 
  5. ^ "WAIPA COUNTY COUNCIL. (Waikato Times, 1879-01-18)". National Library of New Zealand. Retrieved 2017-06-26. 
  6. ^ "SIXTY YEARS' SERVICE (Auckland Star, 1940-01-24)". National Library of New Zealand. Retrieved 2017-06-26. 
  7. ^ a b "Highway Information Sheet 021-0002" (PDF). May 2015. 
  8. ^ a b "Waipa Heritage Trail" (PDF). Waipa District Council. 2008. 
  9. ^ "NARROWS BRIDGE OPENED (New Zealand Herald, 1939-12-07)". National Library of New Zealand. Retrieved 2017-06-26. 
  10. ^ "Highways Information Sheet 021-0000" (PDF). May 2015. 
  11. ^ "NEW NARROWS BRIDGE (New Zealand Herald, 1939-05-26)". National Library of New Zealand. Retrieved 2017-06-26. 
  12. ^ "REPAIRS TO BRIDGE (New Zealand Herald, 1937-10-21)". National Library of New Zealand. Retrieved 2017-06-26. 
  13. ^ "NEW NARROWS BRIDGE (New Zealand Herald, 1939-05-27)". National Library of New Zealand. Retrieved 2017-06-26. 
  14. ^ "Narrows Bridge". Heritage New Zealand. Retrieved 2017-06-26. 
  15. ^ "SH21 Narrows Bridge repairs progressing | NZ Transport Agency". Retrieved 2017-06-26. 
  16. ^ "". Abley Transportation Consultants. Retrieved 2017-06-26. 

External links[edit]

Narrows Bridge 1939 photos -