The Iceberg Principle: The knock on effects of addressing the safety of “special needs” road users

  • Published: Proceedings of the Road Safety Research Policing and Education Conference, 2000
  • Authors: M. King
  • Date Added: 14 Feb 2013
  • Last Update: 14 Feb 2013
  • Format: doc


To estimate wider potential benefits for other road users when problems for special needs road users are addressed.


Five years’ RTI data was examined to produce odds ratios for collision types by age group, time and location. This is used to argue that reducing the risk of RTI involvement for older drivers at intersections will also prevent other casualties. A similar approach is taken to considering RTIs involving child pedestrians. The study is written from the perspective of making engineering interventions.

Key Findings:

  • Focussing engineering interventions on particular groups (whose needs would not otherwise necessarily be targeted) should bring wider benefits to other road user populations.


Older drivers, RTI risk, highway interventions.


The approach taken may be relevant for mobility impaired populations, for example specifically considering their needs when intervening at an oblique intersection. The principle of the study is sound, although the content is relatively simplistic.