Abstract:
Analysis of technically unexplainable accidents has confirmed that accidents could occur not
only due to the user misbehaviors but also due to the lack of purpose designed field of vision
including road courses without adequate contrast to increase alertness. These findings imply
that without a comprehensive understanding of the human limitations a self explaining road
design with low accident risk cannot be achieved. Our current design standards need to be
systematically improved to integrate principals of spatial perceptions in order to manage user
needs and expectations. In the context of Sri Lanka and of many Asian countries user
misbehaviors certainly the most significant contributory factor for the alarming accident rates
they experience at present, yet the fact that lack of purpose designed field of vision though
would be secondary, certainly will aggravate the end repercussion of a misbehaved user.
The duration taken by an average driver to adapt from one traffic situation to the next or to
adjust to a new environment is much longer than the standard reaction time duration
between 2.0-2.5 seconds stated in most of the current design standards. This is particularly
so when information is difficult to find or when users are confronted, with situations
demanding complex decisions.
A critical review of pertinent research and related provisions within road design standards of
US, Canada and UK has revealed that concerns over human limitations have not yet been
satisfactory incorporated in to the standards (G. KANELLAIDIS, 1997) [3].Birth S IBYLLE,
2013[4] reviewed design standards of nine western countries and found that none of the
standards explicitly considers the aspects related to the management of field of vision of
drivers.
This paper submits a comparison of “extents of considerations” of human factor concerns
over the geometric design standards of Sri Lanka, with other standards including
AUSTROADS[2], AASHTO[1] & Chinese based on findings of previous studies. At the end a
framework is discussed allowing the integration of human aspects related to the
management of field of vision of road users into the geometric standards of Sri Lanka.
Citation:
Jayalath, G.R. (2015). Extent of concerns over human limitations in existing road design standards – a literature review over the “status of adequacy” [Abstract]. In H.R. Pasindu (Ed.), Proceedings of the Transportation Research Forum 2015 (p. 12). Department of Civil Engineering, University of Moratuwa. https://uom.lk/sites/default/files/civil/files/TRF%202015_0.pdf