Interchange (road)

In the field of road transport, an interchange is a road junction that typically uses grade separation, and one or more ramps, to permit traffic on at least one highway to pass through the junction without directly crossing any other traffic stream. It differs from a standard intersection, at which roads cross at grade. Interchanges are almost always used when at least one of the roads is a controlled-access highway (freeway or motorway) or a limited-access divided highway (expressway), though they may occasionally be used at junctions between two surface streets.

Terminology

Note: The descriptions of road junctions are for countries where vehicles drive on the right side of the road. For countries where driving is on the left the layout of the junctions is the same, only left/right is reversed.

List of highways numbered 981

A List of highways numbered 981:

Canada

Saskatchewan Highway 981, a provincial highway in the east central region of the Canadian province of Saskatchewan

United States

Louisiana Highway 981 (LA 981), a state highway in Louisiana that serves Pointe Coupee Parish

Pennsylvania Route 981 (PA 981), a state highway which runs across Westmoreland County

309 Road

The 309 road is a 22-kilometre (14 mi) long gravel road between the towns of Coromandel and Whitianga in New Zealand.

The 309 winds its way from Coromandel, on the west side of the Coromandel Peninsula, over the ranges to Whitianga, on the eastern side.

The road is considered extremely dangerous and deaths among tourists unfamiliar with the road and in unfit vehicles are common.

Places of interest along the road include Waiau Falls and the Kauri Grove, a stand of mature kauri trees.

Location

References

External links

Coordinates: 36°50′48″S 175°33′15″E / 36.846767°S 175.554208°E / -36.846767; 175.554208 (309 Road - nominal location)

2+2 road

A 2+2 road is a specific type of dual-carriageway being built in Ireland and in Sweden and in Finland, consisting of two lanes in each direction separated by a steel cable barrier.

These roads do not have hard shoulders and therefore they cannot be designated as Motorway at some future date. The Irish variant,however, has 3.5m lanes where there are a number of Swedish variants some with 3.25m wide 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. The United States has 80,000 km of roads that fit this description.

First 2+2

The first road of this type opened in December 2007 as a new greenfield section of the N4 national primary route which joins Dublin to Sligo.

See also