Following the successful completion of a series of pilot projects and trial sites, Siemens Mobility installed its first ‘production’ Plus+ traffic signal control system for Coventry City Council in June.
The system was commissioned into service on a busy intersection on the B4106, one of the main routes into the city. Keith Manston, head of product management, intelligent traffic systems, Siemens mobility Ltd, gives us an exclusive insight into the scheme.
The programme was delivered as a complete turnkey package (including design, civils and temporary traffic management), with Siemens Mobility contracting Roadtech Cutting Services to undertake the civils works.
Ben Gray, highway network manager at Coventry City Council, says: 'Coventry has long been at the forefront of traffic and automotive technology and we always try to incorporate innovative solutions into our work.
'We are therefore excited to be the first UK authority to install Plus+, which will shape and change the way we work and install future schemes.
'With Plus+ being much quicker and easier to install, there is less risk and cost to the authority, enabling us to provide a better service to people who visit, live and work in our city.'
After a significant development effort, the work in Coventry marked a major milestone for this new traffic signal technology, developed to deliver on-street resilience and reliability, as well as fast and cost-effective installation for both new and refurbishment projects. Plus+ uses distributed intelligence with simple power and data cabling to reduce overall installation and maintenance costs and increase intersection availability.
The installation at Coventry’s Allesley Old Road saw a complete refurbishment of a MOVA controlled intersection and included new Plus+ pedestrian facilities. The system will be monitored by Coventry City Council’s urban traffic control and Stratos traffic management systems.
Andy Wilden, technical support engineer at Siemens Mobility, says: 'Site installation started well, with cable runs, installation, termination and testing all being much quicker and less expensive than traditional methods, due to the site being linked together in a series of short cable runs.
'Having installed the street equipment, and with all hardware labelled ready for installation, we made use of a new Plus+ feature, using the system’s installation app to scan the serial number bar code on each of the signal Nodes (typically a RAG or Nearside). This then generated the final site layout configuration and imported it into the controller.
'Connecting to the controller was then fast and straightforward, with just four cables needing to be arranged in two rings. With only 16 cores in total, this job took minutes, a task which traditionally would have taken at least a day.'
This 14-pole scheme required just over 500 metres of Plus+ cable, weighing 180 kilogrammes, whereas a traditional approach would have needed nearly double the quantity, 942 metres, and nearly five times the weight at 850 kilogrammes.
This reduced cabling requirement had a significant impact on scheme cost as well as providing, storage and safety benefits for the installation team. It also provided sustainability benefits, not only in the raw materials that were saved, but also in the reductions in both energy and carbon that were required to deliver and install the complete project.
The Smart Loop functionality that Siemens Mobility will be introducing later this year will provide even greater cable savings, as individual loop feeders will not have to be routed all the way back to the controller cabinet.
Mr Wilden continues: 'Using the Plus+ discrepancy report, we then checked for any issues, with the system pinpointing exactly any faults found, and then followed standard commissioning procedures - including flashing out, red lamp monitoring and detection checks. Green conflicting is no longer required due to the design integrity of the Plus+ system. Taking into account that we were employing new processes from start to finish, the overall savings from installation and engineering were significant.'
For the scheme, system configuration work was carried out off-site in factory-controlled conditions, further reducing the amount of site time required for the installation team and so improving site safety. Disruption to road users was also minimised on this busy corridor into the city.
Because of its topography, the Coventry site didn’t fully exploit the potential of Plus+ in terms of a reduction in the amount of civils work required, although as Roadtech’s Mark Davis observes, the amount of cabling needed was significantly reduced: 'Rather than having to run 20-core cables to each pole from the controller, for this site just one four-core cable was ‘daisy-chained’ around the site which made a massive difference. The cabling process was so much quicker and more straightforward than we would normally see.'
Typically, the same cable type that would ordinarily be used for loop feeder applications can be used and the number of individual cables and cable cores required to service any given intersection is greatly reduced.
To offer the maximum flexibility and further minimise the number of cables required, the Plus+ controller supports several cable topologies, including rings, arms and spurs, which can be used together depending on the physical layout of the intersection.
When the ring topology is used, the system is highly tolerant of cable breaks; even those caused for example, by the cable being cut during street-working accidents and typically will continue to function fully even after the cable has been cut.
Plus+ has been designed with dedicated failsafe signal heads and pedestrian indicators, as well as new smart loop modules to make sure that the overall system is tolerant of individual component and cable damage. This results in higher intersection availability and most significantly, reduced disruption to road users.
As well as the advantages coming from the quicker and safer installation and the robust nature of the design, the Plus+ system also includes enhanced ‘self-checking’ and diagnostics which provides additional protection against false signals being shown on-street due to error or deliberate acts.
Plus+ benefits
- Up to 80% less cabling and ducting.
- Reduced installation times mean less time on street for installation teams, reduced temporary traffic management requirements and less disruption to road users.
- Increased safety on-street both during installation and day-to-day operation.
- Reduced time working at height.
- Cables are lighter, aiding logistics and protecting the health and safety of your workforce.
- Increased resilience to external damage and internal component failure, meaning improved availability.
- Allows for the efficient pre-assembly of poles and heads.
