Christchurch TransIS xml Feed

The below is an overview and explanation of what TransIS can offer, in order to assist developers to
understand the context of the information and effectively configure their own applications.
Christchurch TransIS xml Feed
Last Updated: 2 Oct 2014.
Getting Started: What is the Christchurch TransIS xml Feed?
The traffic signals (traffic lights) in Christchurch are controlled by a system called SCATS (Sydney
Coordinated Adaptive traffic System). SCATS was originally developed in Sydney. Christchurch
started using SCATS in the late 1980’s.
SCATS in Christchurch is managed by three ‘regional’ servers. Each regional server manages specific
intersections. There are currently 280 signalised intersections managed by the Christchurch SCATS
SCATS is an adaptive system, which means it makes adjustments to ‘green-time’ on-the-fly, based
on the degree of saturation (congestion) at the controlled intersection, and any other intersections
in the roading network which are linked to that intersection.
The degree of saturation is determined by the signals controller, using inductive loops embedded in
the pavement surface.
At a basic level, the higher the degree of saturation, the greater the congestion at the intersection.
TransIS produces an xml file which is pushed to the developer, following an initial login and data
Each regional server updates its degree of saturation to TransIS every 15 minutes. TransIS publishes
this data immediately, meaning that the xml feed from TransIS is generally updated every five
*Please note that 15 minutes is an industry standard for this type of data. The degree of saturation
can only be measured during the green-time. Some intersections are running close to three minute
cycle times, and any approach might only have 30 seconds of green during that time. Updating the
degree of saturation any more regularly can lead to swings in the value; depending on how many
times each specific approach receives green-time in the measured period.
Known limitations of the data
As the regional servers only update the degree of saturation every 15 minutes, the data
(although aggregated) is up to 15 minutes old when it is published. Some of our peaks in
Christchurch come and go within that time-frame.
Because of the current ongoing works occurring on the road surface, the inductive loops in
the road surface are being damaged, or temporary traffic management is directing vehicles
through intersections without taking vehicles over the inductive loops. This can indicate an
inaccurate degree of saturation, when in fact the saturation is high due to the road works,
but not able to be accurately measured by the system.
CTOC operators often need to make temporary changes to intersection setups for road
works, or damage to inductive loop detectors. During these periods, the saturation data
from these intersections will not be accurate.
What Does The Data Look Like?
The data is pushed to the developer from the TransIS server. For a detailed breakdown of what the
data looks like, please contact [email protected]
Accessing and using the data
The Christchurch TransIS Url is made available following successful application, under the creative
commons Attribution licence 3.0 New Zealand.
Next Steps
For access to this API and any additional documentation available, please email [email protected]
with the following details:•
Company (where applicable)
Contact number (including international dialing code)
Email address (So we can notify you of any upgrades or changes to the feed)
An overview of what the data will be used for