Basic Traffic Signal Design – for modellers and designers
The New South Wales branch of the AITPM is holding a “Back to basics” forum on the 26th of October 2017.
Long time AITPM member Alan Finlay who has served the Institute in many functions and is now the Assistant newsletter editor, will be presenting a paper titled “Insight to Basic Traffic Signal Design”.
Australia has lead the field in developing advanced systems of traffic signal control.
But Alan says many traffic engineers and managers need to understand the ideas and the details of the operation of the systems.
Sydney has a very proud history of developing a very sophisticated traffic signal management system scats and it continues to be developed and enhanced. But it's important that people understand the basic principles that underlie the operation of traffic signals generally and that's the sort of things that I'll be trying to cover in my presentation.
It's not just a case for people who are actually designing specific intersections it's also critical for people who are using transport models that incorporate factors about signalised intersection operations.
In my experience both in the public sector and more recently in consulting suggests that there are a lot of people using for example the program SIDRA to assess intersection operation but not all of those people perhaps understand the basic traffic signal operation as well as they might and that sometimes leads to unexpected results from the models.
It's just a very simple thing and one of the most common errors I see in SIDRA, is SIDRA defaults to what we would call long walks in the pedestrian features. So if you don't actively take steps to turn offer a particular function SIDRA will assume that every pedestrian feature has the walk go almost for the length of the phase. And so the flashing red man will operate for the last however long it needs to be for the length of the crossing. But in practice in NSW practice certainly it's more typical of the walk only displayed for about six or eight seconds at the start of the phase and then it's straight away goes into flashing red man. So it's if it's left to its own devices Sidra will make every pedestrian crossing a long walk. Whereas in practice most pedestrian crossings have short walks.
Information about the forum can be found on our website
Videos
RMS NSW - Signals and Signs for road users
SIDRA – Intersection 7
