Effect of intersection angle on a time-gap based intersection sight distance model

Cole, David Michael (2018) Effect of intersection angle on a time-gap based intersection sight distance model. [USQ Project]


An intersection is considered skewed when the roads intersect at an angle other than 90°. Skewed intersections generally result in longer passing time for the vehicles through intersections. This means drivers generally have a longer distance to travel when crossing the intersection or making certain turning manoeuvres, which results in increased exposure within the intersection. The main aim of this project is to determine if drivers require any additional time to safely undertake a crossing or turn manoeuvre at a skewed intersection compared with a 90° intersection.

Cox and Cole (2013) identified issues with the Safe Intersection Sight Distance (SISD) model, which led to research to replace the SISD with a time-based intersection sight distance model. From research on a time-based intersection sight distance model (Cox & Cole 2013, 2016), it was identified that the effect of intersection skew (angle) would need to be further investigated for specified design vehicles.

This research project aims to determine what effect intersection skew has on intersection sight distance and the associated time-gap for each vehicle type making that manoeuvre. And whether a skew correction adjustment value (in terms of time) is warranted and determine the correction adjustment values. From a literature search no research has been found that has determined what impact intersection skew has on a time-based intersection sight distance model. The project also aims to confirm timegaps for four-lane and six-lanes on a 90 degree intersection which forms the base case to compare the skewed intersection results to.

To determine the effect of skew on a time-gap for a particular vehicle, several programs and tools developed by the Queensland Department of Transport and Main Roads (TMR) have been utilised using a methodology developed in previous research to determine the speed reductions an entering vehicle has on the major road vehicles.

By completing this research project it will address the knowledge gap about the effect of intersection skew on a time-gap and its effect of the entering vehicle and the vehicles it effects in terms of speed reduction.

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Item Type: USQ Project
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Somasundaraswaran, Soma
Qualification: Bachelor of Engineering (Honours) (Civil)
Date Deposited: 10 Sep 2021 05:57
Last Modified: 27 Jun 2023 04:54
URI: https://sear.unisq.edu.au/id/eprint/40653

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