Case study · Glasgow City Council
A city’s traffic signals, taken off the phone line
Glasgow replaced most of the leased lines behind its traffic signals with a secure NOW Wireless mesh network. More than two decades on, the network carries over 900 signalised junctions — and now the sensors, cameras and AI that sit alongside them.
Headline results
The challenge
Around 800 junctions, 450 leased lines, and a bill of about £1 million a year
Glasgow City Council set out to bring its traffic signal system up to UTMC (Urban Traffic Management and Control) standards. In doing so it saw a second opportunity. Each junction depended on a leased telecom circuit back to the central system — around 450 lines across the city, costing in the region of £1 million a year in recurring charges.
The council wanted to remove most of those lines and replace them with a secure wireless network of its own: a one‑off investment that would free up revenue budget, year after year, to spend on the highway network itself.
What the council needed
- UTMC‑standard communications to every signal controller
- A secure network, resistant to interference and intrusion
- No single point of failure between the street and the control room
- A large, permanent reduction in recurring communications cost
- Room to grow: more junctions, and later more devices
The project
A trial on one street, then the whole city
NOW Wireless proposed a mesh network to replace 80% of the circuits connecting the traffic light controllers to the central management system. A trial was installed along a single street to prove that a mesh network could work in a dense city environment.
Each junction on the street was given a mesh radio to talk to the junctions around it. The radio technology was designed to military standards for use at street level, where interference is a real risk: it is resistant to interference and blocking, and the network self‑forms and self‑heals, so a failed link is routed around automatically.
Two leased circuits were left in place to carry the traffic back to the SCOOT (Split Cycle Offset Optimisation Technique) system at the council building. If one failed, the data rerouted to the other — removing the single point of failure that a line per junction had always carried.
From a leased line per junction to a self‑healing mesh with two shared backhaul circuits.
The outcome
From a trial to the UK’s reference mesh network
The trial ran for a year and a half, after which the council asked for a full live system. More than two decades on, over 900 signalised junctions run over the NOW Wireless mesh network, and the recurring communications saving has been banked every year since.
The network has become the city’s street infrastructure. Over the last several years Glasgow has added NOW Wireless sensors to it: Bluetooth detectors for journey times, air quality devices for pollution, and AI connected to new and existing CCTV cameras for vehicle counting and classification, predictive air quality and route analysis. All of it is analysed and displayed in SenseView, the NOW Wireless real‑time data platform.
Glasgow today
- Junctions on the mesh
- 900+
- Leased lines removed
- 80%
- Journey time
- Bluetooth detectors
- Air quality
- XA Series sensors
- AI
- On new and existing CCTV
- Data layer
- SenseView
The network was built for signal communications. It now carries the sensors and AI the city needs next.
What this means for you
One network, paid for once, that keeps paying back
If your signals still depend on a leased line per junction, the Glasgow model applies directly: a trial on one corridor, a staged roll‑out, and a network that then carries everything else you put on the street. See Traffic Light Infrastructure for how a wireless junction is built, and Smart Junctions for the AI detection that runs on it.
Talk to us
Start with one street
Tell us where your communications costs are highest and we will scope a trial corridor on your existing signals.