Guidelines for retro-fitting existing roads to optimise safety benefits: a practitioner's experience and assessment of options for improvement

Crash data shows a consistently high level of run-off-the-road type crashes on high speed, undivided roads (90 kmh and greater) in New South Wales. The NSW Roads & Traffic Authority (RTA) is committed to reducing the number and severity of vehicle crashes by ensuring a safe driving environment. This includes ensuring road designs for curve radii are compatible with a safe systems approach to road safety. The RTA implements strategies to reduce the number of crashes when designing new alignments and upgrading existing alignments. Options to reduce crashes include reducing speed limits; widening and sealing the shoulder; removing roadside hazards; installing profile edge-line marking; installing advisory curve speed warning signs and installing curve alignment markers. More expensive solutions include increasing super-elevation on sealed shoulders where possible; removing roadside hazards at run-off areas and levelling of batter slopes to at least 4:1 or installation of an appropriate safety barrier where a run-off area is not available. Application of research findings to focussed allocation of available funds can and has resulted in significant reductions in road trauma in NSW.