Road signs in the Republic of Ireland mostly differ from the traffic signs used elsewhere in Europe. Directional signage is similar to that of the United Kingdom, but is bilingual and with distances in kilometres. Apart from directional signage, the basic prohibitory signs such as "no left turn" and "no right turn" are among the few standard signs used in the Republic of Ireland. The most widespread signage, hazard or warning signs, employs the yellow diamond layout used in the United States, Australia and elsewhere, but nowhere else in Europe. The actual symbols used on these warning signs, however, often bear a closer resemblance to those used in the UK and the rest of Europe than to those seen in the US. Some mandatory signs (one way, left turn only, right turn only) are unique to Ireland. In January 2005, Ireland adopted metric speed limits. Around 35,000 existing signs were replaced and a further 23,000 new signs erected bearing the speed limit in kilometres per hour. To avoid confusion with the old signs, each speed limit sign now has "km/h" beneath the numerals.

Directional signage is similar, though not identical to the United Kingdom design. Place names are listed in Irish in mixed case italics, followed underneath by the relevant English language place name equivalent in all capital letters. The UK 'Transport' and 'Motorway' typefaces are used, although the Irish language text uses a distinctive local variant of it. If the sign is in the Gaeltacht, or no English place name exists, or is very similar (for example Dún Laoghaire or Port Laoise), only the Irish place name is given. Due to the need to signpost in both languages, usually a limited number of destinations will be signposted. If a destination can be reached by following a route which is a spur from that route, the destination and route number will be shown in brackets. Also, distances are shown in kilometres.

Road signage in Irish and English

Motorway signs use white text on a blue background. Non-motorway national primary routes use white text on a green background, with the specific route number in yellow bold text. Regional and local county roads use black text on white background. Signs to points of interest (services, institutions, tourist sights) have white text on a brown background. National routes (whether motorway or not) generally have large signs at the approach to junctions showing the exits for various destinations. Some higher specification regional roads including by-passed former national primary routes also have such signage. Large steel plate fingerpost signs are used at roundabout exits. The majority of Irish rural roads use small fingerpost signage at road junctions.

Signage on motorways has previously been near identical to that on UK motorways although in the Republic of Ireland, motorway junctions are not always numbered, or the number is not always signposted. The sign at the actual exit, which in the UK shows the road number to be reached, is replaced by the destination instead. On the M50, in the case of junctions with national routes, the initial advance direction sign is replaced with a list of destinations for that national route. The Republic of Ireland also continues to use the "Motorway Ahead" sign, listing the motorway regulations, which has been mostly discontinued in the UK (the actual sign used is very similar to the version formerly used in the UK).

One feature of road signage in Ireland, particulary along Dublin's quays is that some national primary road signage directs drivers generically to destinations such as "The West" and "The South" and the "The North". While this has been replaced with specific placenames in some cases it remains in use in other areas. In summer 2006, signage for "North" and "South" was erected in Ashbourne at the start of the new N2 dual carriageway. Nevertheless, generally directional signage on major routes shows major or end destinations. Smaller towns and placenames are only shown on signage nearer to that location. Thus travelling on the Irish route network requires some geographical knowledge of the country.

Warning Signs
Warning signs are black on an amber (orangish yellow) background and are diamond shaped. Road works hazard signs are reddish orange. Here are a few that may be unfamiliar to you:

Unguarded level crossing	Level crossing with gates	Level crossing with automatic gates
Sharp rise ahead	Sharp depression ahead	Series of sharp rises or depressions ahead
(School) children crossing	Children (pedestrians) crossing	Roundabout ahead
Road works ahead	Major road works ahead	Diverted Traffic

Regulatory signs
Regulatory signs are mostly circular and mostly black on a white background, with a red border. If the sign contains a prohibition, a red line will diagonally bisect the sign.

In Ireland, the "Give Way" sign, a downward pointing triangle, reads "Yield" (on signs erected prior to 1997: "Yield Right of Way") or, in Gaeltacht areas, "Géill Slí." The international octagonal "Stop" sign is also used.

Speed limit signs have the speed with the letters "km/h" underneath. 120 km/h is used for motorways and high quality dual carriageways.

Clearway - stopping or parking prohibited during times shown	No entry	One way	Stay left
	No vehicles	Yield (to other traffic ahead)	Géill Slí (Yield sign in Irish)

Interesting Signs Found Along the Way

Ceansú Tráchta Traffic Calming	Ná Scortear Do Not Pass	Slán Abhaile Safe Home (Irish)	Safe Home (English)	Level Crossing (as in train)