Plus+ traffic control system
Plus+ provides a complete traffic signal solution suitable for intersections and pedestrian crossing sites in both a standard and small cabinet.
Resilient by design
ST950 Plus+ and the dedicated failsafe components have been designed to be highly resilient to internal failure and external damage. If damage does occur to the traffic signals individual nodes can be ‘hot-swapped’ typically allowing maintenance to be undertaken while the traffic signals remain switched on.
Combined with a design which is able to withstand short circuits that may occur during damage to in-street cables and redundant power supplies, Plus+ can make sure the intersection is kept available and operational during repairs or predictive maintenance.
Cable methodology
itional traffic control systems use many cables to connect street furniture to the traffic controller. A distributed system uses intelligence spread throughout the intersection to significantly reduce individual cable connections using a combination of Arm and Ring cabling meaning that
- fewer, lighter cables are needed
- the cabling approach makes use of low-level access poles much easier
- cabling approach makes pre-assembly of poles and heads more efficient
All of these factors mean that there is a significant reduction in on-street working time, meaning a quicker and safer installation.
Dedicated components
Plus+ offers several new components which facilitate the use of advanced system communication and reduced cable, including:
- ST950 Plus+ controller
- ST950S controller – for small intersections including a new small cabinet design
- ST950SP controller – optimised for pedestrian crossing installations complete with 40 standard pedestrian configurations
- Helios Plus+ signal heads
- Plus+ nearside indicators
- Plus+ wait indicators
- Plus+ SmartLoop
These retain the ‘look and feel’ of their standard ELV family members but include the necessary internal technology to support Plus+ operation.
Designing for Plus+
To help simplify the design process, a free to download AutoCAD plug-in works alongside the widely used KeySignals site layout drawing tools to capture the full information about a junction’s characteristics and component relationships.
By calculating the full parameters for rings and arms (and identifying cable runs and node assignments are within design limits), the design process is made as efficient as possible.
Detection
Plus+ is compatible with standard detection as per the ST950 ELV.
In addition to the standard components Plus+ introduces a new concept in loop detector technology. The Plus+ SmartLoop places detection technology close to the actual detection loops and allows them to connect into the Plus+ communication and power network around a site, eliminating the need for loop feeder cables to be brought back to the controller cabinet further adding to the cable savings.
Installation features
The distributed intelligence and flexible cable methodologies open up new opportunities to further reduce overall scheme implementation costs. Microducting is a method of installing a smaller diameter duct into a carriageway slot, reducing the need for civils works in situations where road closures or road works would cause disruption to the strategic road network.
Using Plus+ in a temporary installation as part of a signal modernisation scheme provides a fully compliant TOPAS 2500 controller with all of the associated features, detection and connectivity removing the need for a secondary system. Due to the architecture of the Plus+ system, as the site works are completed the Plus+ signals can be transferred one at a time into their permanent location whilst the site remains operational.
