High Quality Dual Carriageway

From Wikipedia, the free encyclopedia

N2 Ashbourne bypass,County Meath,Ireland.

A High Quality Dual Carriageway (HQDC) is a category of road in the Republic of Ireland. It is an all-purpose dual carriageway road type of motorway standard, but without the route section being classified as motorway or having motorway restrictions. High-quality dual carriageways have full grade-separated access and are specified as not having junctions with minor roads. Such roads are currently being built in the Republic of Ireland, and will form part of the country's national motorway network when complete in 2010.

While HQDCs or roads of similar type exist in a number of countries (a British example being the A55 road in Wales), this article concentrates mainly on such roads in the Republic of Ireland.

1 Specifications
2 HQDCs in Ireland
3 Future
4 See also
5 External links
6 References

[edit] Specifications

HQDCs are specified as having the same capacity as standard motorways (52,000 vehicles AADT - annual average daily traffic). The road type is all-purpose dual carriageway (D2AP), but with the same specifications as motorway; a carriageway width of 7 metres and a hard shoulder of 2.5 metres. HQDCs are limited access (grade-separated junctions only) and not intended to have junctions with minor roads. Junctions with major roads are grade-separated and to motorway standards.

All HQDCs in Ireland are currently of national primary road standard, and so by default used the national road speed limit of 100km/h. There are exceptions however, as special speed limits may now be specified for specific stretches of road. The N2 Finglas - Ashbourne bypass is of high-quality dual carriageway grade but utilises the motorway speed limit of 120km/h, even though it is not a motorway. It is likely that a number of the new high-quality dual carriageways on the inter-urban routes will use the 120km/h speed limit in the future.

Signage on HQDCs are similar to motorways, and junction numbers may be present (as on motorways, indicated by a white number on a black panel in the corner of signs). However signage on HQDCs uses a green background instead of blue (in the unlikely event of a HQDC being a regional road, black-on-white would be used instead). Also as on other all-purpose roads, signs should include patches for roads of other classifications (on motorways, all signage should bear a blue background).

As high-quality dual carriageways are not motorways, they do not need to conform to motorway regulations, therefore slow-moving vehicles (e.g tractors,farm vehicles etc.) as well as cyclists will be permitted to use these roads. Facilitating this, HQDCs have a regular broken line hard shoulder, rather than the solid line hard shoulder of a motorway. Also, L-Drivers (Learner Drivers), which are not permitted to drive on motorways can do so on a high-quality dual carriageways, as on the rest of the national road network.

[edit] HQDCs in Ireland

Many of Ireland's new inter-urban roads are being built to HQDC standard, as opposed to motorway standard. Roads under construction that are being built as HQDC include the N6 Kinnegad - Athlone Scheme, the N8 Cullahill - Cashel Scheme and the N9 Carlow bypass scheme. These roads will form part of the inter-urban network. Such roads use the (N) national road prefix on signage as opposed to the (M) prefix (used instead of the route's normal prefix where the route or a section of it is motorway). The advantage of a HQDC over a motorway in this regard is that the normal planning permission process is used, rather than the Motorway Scheme process used to create a motorway. However the problem of using the normal planning process is that in theory planning permission could be granted for a direct access for a home or business onto the HQDC; although such direct accesses are now discouraged under public policy, there is no legal impediment. Motorways, by contrast, may only have accesses at junctions and service areas.

A number of the new high-quality dual carriageway schemes will proceed as PPP's (Public Private Partnerships) despite not being motorway schemes. Such roads include the proposed N6 Galway - Ballinasloe project. This road and the N25 Waterford City bypass are the only HQDCs planned at present to be tolled, although the East-Link toll bridge which is a local road is also tolled. All other toll roads are motorways.

The N6 Kinnegad - Kilbeggan scheme features rest stops, which would not be legal at present on roads with full motorway status.

[edit] Future

With the Roads Bill 2007 introducing powers for the Minister for Transport (upon the recommendation of the NRA) to re-classify high quality dual carrigeways as motorways, it is possible that in the future a majority of HQDC's will be reclassified as Motorways. ^[1]. The bill is currently in its final stages of passage in the Oireachtas.