Research part-funded by the Irish National Roads Authority was conducted to investigate road geometric elements and accident rates using data from the Irish National Road authority (NRA) Needs Study Database. Two studies examined accident data for the periods 1990-1998 and 1996-2000. The carriageway types examined were motorway, dual carriageway, three-lane, undivided improved wide two-lane, undivided improved standard two-lane and undivided unimproved two-lane. Interurban accident rates for the Irish national road network were calculated. Motorways were shown to be the safest, followed by dual carriageways. Two-lane undivided roads were the most dangerous in terms of the all-accident rate, but three-lane roads showed a high fatal accident rate. The accident rates were compared with those obtained in other studies and in other countries. A regression analysis was carried outinto the relationship between geometric elements (hard shoulder, medians,intersections, verges, grade, curves and passing sight distance) and safety. For the covering entry of this conference please see ITRD E132365
Samenvatting