Trunk Roads in Ireland - Trunk Roads and Link Roads

Trunk Roads and Link Roads

Major roads were marked with "T" for Trunk Road, less important roads were marked with "L" for Link Road.

Trunk Roads connected major towns to each other while passing through smaller towns and villages.

Several trunk routes were designed to connect towns in different regions of Ireland (for example, the T41 from Enfield to Kilrush, via Tullamore, Portumna, Scariff and Ennis) while other roads (for example, the T66 Ring of Kerry route) were designated scenic routes.

Link Roads connected smaller towns and villages to each other and to the Trunk Road network.

There were eighty-four Trunk Roads in total, numbered from T1 to T77 consecutively (plus T4a, T11a, T12a, T21a, T28a, T50a and T72a). Roads with the 'a' suffix branched off roads with the same number. For example, the T4a branched off the T4 at Ballinasloe in County Galway and the T12a branched off the T12 to serve Cobh in County Cork.

The first nine Trunk Roads (T1, T2, T3, T4, T4a, T5, T6, T7, T8) radiated out from Dublin (with the T8 branching off the T7 at Enniscorthy) and followed an anti-clockwise pattern. This pattern was similar to the existing anti-clockwise pattern which the National routes and motorways radiating out of Dublin now follow. The pattern was interrupted by the T35 (Dublin-Cavan-Donegal route) which came between the T2 and the T3 and the T42 (now N81), T43 and T44 which came between the T5 (T6) and the T7 routes.

Unlike the present system, where each road (whether N- or R-) has a unique number, under the Trunk and Link Road system, Link Roads were numbered separately beginning with L1. These L (for Link Road) numbers are not related to the current Lxxxx numbers for Local Roads.

Confusingly, some old road signs still show the former (now obsolete) Trunk and Link road-numbers.

Trunk Roads were broadly equivalent to the present National routes, and Link Roads to the present Regional roads. Most of the National Primary and National Secondary routes had been Trunk Roads and generally they followed the routes of these Trunk Roads, albeit with a different numbering system. However, some National Primary and Secondary routes also incorporated Link Roads and unclassified roads into their routes. After the introduction of the new road numbering system, some Trunk Roads (either in whole or in part) were downgraded to Regional roads, effectively 'de-trunked'Trunk road#De-trunking: Ireland.

A notable feature of the former system was multiplexing (or concurrency), where a section of road was designated by two or more route numbers. Examples of multiplexes include the T7/T12 multiplex between New Ross and Waterford, the T6/T13 multiplex between Cahir and Kilheffernan (east of Clonmel), the T28/T36 multiplex between Newcastlewest and Abbeyfeale and the short T19/T21 multiplex between Thurles and Toor. The road between Cavan, Butlersbridge, Cloverhill and the border with Northern Ireland (near Wattle Bridge in County Fermanagh) was a triple multiplex of the T10, T15 and T35 routes.

Three routes (T15, T22, T35) had sections which were disconnected from the rest of the route by roads which crossed through Northern Ireland. These routes lost their Trunk Road designations through Northern Ireland, regaining them on exiting Northern Ireland. The T15 crossed the border several times between Cavan and Clones, alternating between the T15 and the A3 designations.