2+2 road

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An example of a 2+2 dual-carriageway in Ireland (the N4)

A 2+2 road is a specific type of dual-carriageway that exists primarily in Ireland,[1] Sweden,[2] and Finland,[3], consisting of two lanes in each direction separated by a steel cable barrier.

These roads do not have hard shoulders and therefore cannot be designated as motorways in the future. However, they may be designated as limited-access roads, as such roads do not require the physical standard of motorways to be designated as expressways. The Irish variant has 3.5-metre-wide (11 ft) lanes[4] where there are a number of Swedish variants[5] some with 3.25-metre-wide (10.7 ft) lanes.

Junctions are generally at-grade roundabouts and minor roads cross under or over the mainline without connecting. They are also known as "type 2 dual-carriageways" by the Irish National Roads Authority. These roads look similar to expressways, except that expressways often have interchanges, large medians or concrete barriers between traffic.

History[edit]

First Irish 2+2[edit]

In Ireland first purpose-built road of this type opened in December 2007[6][7] as a new greenfield section of the N4 national primary route which joins Dublin to Sligo.

See also[edit]

References[edit]

  1. ^ http://goo.gl/maps/8nI5Y
  2. ^ http://goo.gl/maps/Vfylm
  3. ^ http://goo.gl/maps/kO9aX
  4. ^ "Irish Design Standard (pdf)". Archived from the original on 2016-03-03. Retrieved 2013-07-28.
  5. ^ Swedish 2+2 Types (In Swedish)
  6. ^ N4 Drumsna Longford (Dromod Roosky)[permanent dead link]
  7. ^ Ireland's First 2+2 Road Type Opens in Dromod Roosky Archived 2009-07-26 at the Wayback Machine