Reference

Road & bridge standards

Plain-English reference pages on the published standards that govern signage, parapets, speed limits and bridge inspection in Ireland.

W009R warning signThe Irish road sign warning of a side road on the outside of a bend.Chevron boards W062Directional chevron boards marking a sharp change of direction.Bridge parapet containment heightWhy a vehicle parapet's height is measured from the road surface, and the modern standard.Special speed limit ordersHow a local speed limit is set or changed on an Irish road.Principal bridge inspectionWhat a principal inspection of a road bridge is, and how often it is done.Road restraint systems on bridgesThe purpose of a vehicle restraint system where there is a drop.Chainage on a road works scheduleWhat 'chainage' means when reading a council roads programme.Surface dressing and resealing (RSR)What a road reseal is, and how it changes a road surface.Sight Distance and Stopping Sight DistanceThese standards define the minimum unobstructed view a driver needs to safely react to hazards or stop their vehicle.Junction Visibility SplaysThese standards specify the clear, unobstructed areas required at junctions to allow drivers to see approaching traffic.Road Markings: Centre Line and Edge LineThese standards dictate the design, placement, and materials for lines that define the centre and edges of a carriageway.Hazard Warning LineThis specific road marking warns drivers of an upcoming hazard or a change in road conditions requiring extra caution.Anti-Skid High Friction SurfacingThis standard relates to the application of specialised road surface treatments designed to significantly increase skid resistance.Road Traffic ActsThese are primary legislative documents that govern all aspects of road use, including vehicle standards, driver behaviour, and road infrastructure.Road Drainage and GulliesEffective road drainage is crucial for road safety and longevity, preventing water accumulation that can lead to aquaplaning and structural damage.Camber and CrossfallCamber and crossfall are essential geometric features of road design that ensure surface water drains effectively from the carriageway.Superelevation on BendsSuperelevation, or 'banking', on road bends is a design feature that helps vehicles safely navigate curves by counteracting centrifugal forces.Kerbing and Edge DetailsKerbing and edge details define the boundaries of the carriageway, providing structural support, drainage control, and safety for road users.Passive Safety of Roadside FurniturePassive safety standards for roadside furniture aim to minimise the severity of injuries to vehicle occupants in the event of a collision.Bridge Load Ratings (BD 21/01)This standard outlines the methodology for assessing the load-carrying capacity of highway bridges and structures.Scour Protection at Bridge Piers (BD 97/12)This standard details the requirements for protecting bridge foundations from erosion caused by flowing water.Bridge Parapet Types (BD 52/93)This standard classifies and specifies the performance requirements for different types of bridge parapets.Bridge Inspection Intervals (BD 63/17)This standard sets out the frequency and types of inspections required for highway bridges and structures.Masonry Arch Assessment (BD 21/01)This standard provides guidance on the assessment of the load-carrying capacity of masonry arch bridges.

Last updated 2026-08-05. This is a living record — findings are added as dated entries and prior versions remain visible.