chapter  8
36 Pages

Cross-Section Design

AASHTO (2011a) defines the cross-section as ‘A vertical section of the ground and roadway at right angles to the centreline of the roadway, including all elements of a highway or street from right-of-way line to right-of-way line’. Although many designers are happy to spend considerable periods of time on the horizontal and vertical alignments, the cross-section seems to be in the nature of an afterthought. Other than to accept whatever cross-section the road agency deems to be appropriate for the project, it seems to command little attention or thought. And yet this Cinderella is used to define the very nature of the road being designed. The two-lane two-way road, the 2 + 1, the six-lane dual-carriageway are nothing more or less than names describing the cross-sections of these roads.