The Republic of Ireland operates left-hand traffic on all public roads. Northern Ireland, as part of the United Kingdom, follows the same left-hand system. All road signage in the Republic of Ireland displays distances in kilometers, while Northern Ireland uses miles. Speed limits in the Republic appear in kilometers per hour: 50 km/h in built-up areas, 80 km/h on regional roads, 100 km/h on national roads, and 120 km/h on motorways. Northern Ireland posts limits in miles per hour: 30 mph in towns, 60 mph on single carriageways, and 70 mph on dual carriageways and motorways. This metric-imperial divide creates a practical complication when crossing the border, which has no physical checkpoints but requires immediate mental conversion of speed awareness.
Dublin operates three toll roads: the M50 barrier-free toll system, the Dublin Port Tunnel, and the East Link Bridge. The M50 uses electronic collection only through video recognition or pre-registered tags, with payment required by 8pm the following day through the eflow website or retail outlets. Failure to pay within this window generates an 80 euro penalty. The M1, M3, M4, M7, M8, and the Limerick Tunnel also charge tolls ranging from 1.90 to 3.10 euros for cars at barrier plazas. Toll tags offering discounted rates are available from Transport Infrastructure Ireland for frequent users. Northern Ireland motorways carry no tolls.
Bus Éireann operates the national intercity and regional bus network throughout the Republic of Ireland from its headquarters in Broadstone, Dublin. Routes connect all major towns with frequency varying from hourly services on corridors like Dublin-Cork to three daily departures on rural routes such as Donegal-Sligo. The Expressway brand designates limited-stop intercity services between major cities with onboard WiFi and charging points. Standard intercity fares range from 12 to 25 euros for advance online bookings, rising to 15 to 35 euros for same-day tickets purchased at stations. Children under three travel free, ages three to fifteen receive half fare, and holders of Student Leap Cards get fifteen percent reductions. The Dublin-Galway expressway route runs every hour during daylight with a journey time of two hours thirty-five minutes covering 219 kilometers.
Dublin Bus operates approximately 120 routes within Dublin city and surrounding suburbs using a fleet exceeding 900 vehicles. Single fares range from 1.65 euros for one to three stages to 3.30 euros for journeys exceeding thirteen stages, payable in exact change to the driver or through the Leap Card contactless payment system. The Leap Card offers discounted fares starting at 1.54 euros and daily caps of 7 euros for bus-only travel or 10 euros across all Dublin public transport. Services generally operate from 5:30am to 11:30pm on weekdays, with Nitelink routes serving major corridors Friday and Saturday nights until 4:30am at a flat fare of 6.50 euros. Real-time information appears at major stops and through the TFI Live app showing GPS-tracked arrival predictions.
Iarnród Éireann runs all train services in the Republic of Ireland from its operational center in Connolly Station, Dublin. The intercity network radiates from Dublin to Cork, Limerick, Galway, Westport, Sligo, Waterford, and Rosslare with no direct connections between regional cities that bypass Dublin. The Enterprise service, jointly operated with Northern Ireland Railways, runs eight times daily between Dublin Connolly and Belfast Lanyon Place with a journey time of two hours ten minutes covering 166 kilometers. Standard class fares for Dublin-Cork, the busiest route at 265 kilometers, range from 19.99 euros for advance online purchase to 62 euros for flexible same-day tickets. First class adds approximately forty percent to these fares for larger seats and complimentary refreshments.
The Dublin Area Rapid Transit system, known as DART, operates electric commuter rail along 53 kilometers of coastal track from Malahide and Howth in the north to Greystones in the south. Service frequency reaches every ten minutes during peak hours and every fifteen to twenty minutes off-peak, running from approximately 6am to midnight on weekdays. Fares operate on a zone system from 1.70 euros for a single zone to 3.60 euros for end-to-end travel when using Leap Card, or 2.15 to 4.55 euros for cash tickets. The DART+ expansion program, approved in 2021 with completion scheduled through 2035, will electrify an additional 150 kilometers of track and extend service to Drogheda, Celbridge, and Hazelhatch.
Luas, Dublin's light rail tram system, opened its Red Line in 2004 and Green Line in 2009, now operating 67 trams across 42.5 kilometers of track serving 67 stops. The Red Line runs from The Point through central Dublin to Tallaght and Saggart, while the Green Line connects Broombridge to Bride's Glen via St. Stephen's Green. Both lines intersect at O'Connell Street and Abbey Street following the Cross City extension completed in December 2017. Trams arrive every four to five minutes during peak hours and every ten to fifteen minutes off-peak. Leap Card fares range from 1.68 to 2.60 euros depending on zones crossed, with cash tickets costing 2.10 to 3.30 euros purchased from platform machines before boarding. Revenue protection officers conduct random checks with 45 euro fines for fare evasion.
Translink operates all public transport in Northern Ireland through three brands: Ulsterbus for regional services, Goldline for intercity express routes, and Metro for Belfast city buses. The Belfast-Derry Goldline 212 express runs twelve times daily covering 113 kilometers in one hour forty minutes with standard returns costing 18.50 pounds. Metro operates 100 routes within Belfast with cash fares of 2 pounds flat rate or 1.60 pounds using a Glider smartcard. The Glider branded bus rapid transit system, launched in September 2018, runs articulated buses every seven to eight minutes along dedicated lanes on two cross-city routes with level boarding and pre-paid ticketing at 1.70 pounds per journey.
Northern Ireland Railways maintains three routes from Belfast: the line to Derry via Coleraine and Ballymena, the Bangor line serving commuters east of Belfast, and the enterprise route to Dublin. The Belfast-Coleraine-Derry line covers 146 kilometers with eight trains daily Monday to Saturday and five on Sunday, requiring two hours ten minutes for the full journey. Return fares from Belfast to Derry cost 21 pounds for adults or 10.50 pounds for children aged 5-15. The Bangor commuter line runs every thirty minutes during peak times on the 22-kilometer route taking approximately twenty-five minutes. A Day Tracker ticket valid on all Translink rail and bus services costs 17.50 pounds.
Car rental in Ireland requires drivers to be minimum age twenty-five for most companies, though some accept age twenty-one to twenty-four with daily surcharges of 15 to 30 euros. An international driving permit is not legally required for visitors from EU countries, the United States, Canada, Australia, or New Zealand, but insurance companies may specify it as a policy condition. Rental rates for compact manual transmission cars start around 35 euros daily or 180 euros weekly during off-season, rising to 70 euros daily or 400 euros weekly in July and August. Automatic transmission vehicles add approximately thirty percent to these rates. Collision damage waiver insurance typically adds 15 to 25 euros daily unless declined with proof of coverage from credit card or personal auto policies.
The island of Ireland contains approximately 99,830 kilometers of paved roads in the Republic and 25,856 kilometers in Northern Ireland. The Republic designates roads as motorways (M-prefix), national primary roads (N-prefix single digit), national secondary roads (N-prefix double digit), and regional roads (R-prefix). Motorways connect Dublin to Cork, Limerick, Galway, Waterford, and the border with Northern Ireland, with the M1 being the first motorway opened in 1983. The Wild Atlantic Way, a 2,500-kilometer signed coastal touring route from Donegal to Cork, opened in 2014 and uses existing national and regional roads marked with special signage. Ireland's Ancient East touring route covers 5,000 kilometers across seventeen counties in the east and south.