TITLE:
Interchange Sight Distance and Design: Aspects and Implementation
AUTHORS:
Shy Bassan
KEYWORDS:
Interchange, Sight Distance, Decision, Ramp, Terminal
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.11 No.3,
September
30,
2021
ABSTRACT: The primary purpose of an interchange is to enable
an appropriate level of access to the freeway in a safe and beneficial way to
the driver. It improves road safety and traffic operation by reducing or
eliminating traffic conflicts that would occur if grade separation were not
provided (e.g. intersection). Crossing conflicts are eliminated and turning
conflicts are either eliminated or minimized. The paper focuses on sight
distance criteria in the geometric design of interchanges and junctions,
specifically, implementation of stopping sight distance (SSD) and decision
sight distance (DSD). These issues incorporate implementation of sight distance
policy for: ramps’ geometric design, ramp terminals’ components, and basic
lanes’ reduction. These sight distance criteria can alleviate safety by
reducing conflicts and confusion to the driver and by keeping alignment simple,
direct, and consistent. Specifically, DSD affects traffic control and
intelligent transportation systems applications.