Traffic enforcement case studies
Enforcing mandatory right turns
from multiple approaches
The challenge
At a busy yellow box junction, the London Borough of Ealing was experiencing frequent traffic contraventions. The most serious safety concern was drivers failing to obey mandatory right-turn restrictions.
On each approach to the junction, the right-hand lane was reserved for right-turning traffic. Drivers regularly used these lanes to continue straight ahead or turn left, creating unsafe vehicle movements that the council were required to enforce.
Kiowa Systems Ltd was one of three companies invited to demonstrate whether unattended camera technology could detect these contraventions and produce reliable evidence.
The solution
The trial required the large junction to be monitored in two directions simultaneously. Kiowa engineers mounted a MetroVision Unattended Outstation on existing street furniture and positioned it to capture vehicles travelling towards the camera as well as vehicles crossing the scene from the left.
Unlike enforcement systems that depend on ANPR, MetroVision tracks every vehicle through the full scene. This allowed the Outstation to monitor the whole box junction scene and follow multiple vehicles simultaneously.
The results
Kiowa was the only supplier to complete a successful trial at the selected site. Once installed, the Unattended Outstation monitored complex vehicle movements across the junction and identified the targeted contraventions. Its performance demonstrated that the technology could meet the site’s demanding enforcement requirements, and the council were impressed with the Outstations performance and the outcomes.
Core compatibility
- Full trajectory tracking — Tracks complete vehicle paths through complex junction geometry without relying on number plate recognition.
- Automated evidence generation — Clips video, selects the clearest close-up stills, and automatically redacts identifying details of vehicles and bystanders.
- Efficient operator validation — Presents evidence for single-click review and validation.
- End-to-end integration — Evidence is automatically enriched with vehicle details provided by the DVLA to complete the evidence pack being sent to the back-office notice processing system.
“I was sceptical that any automatic enforcement camera could cope with the complexities of the junction, but I was thoroughly impressed with MetroVision and its ability to use AI to track and capture the contraventions we were interested in.”Pritesh Kalam, Parking Operations Manager, London Borough of Ealing
Enforcing a yellow box junction and a bus lane
from a single Unattended Outstation
The challenge
At the Greenford Road / Otter Road yellow box junction, vehicles regularly stopped within the marked area, obstructing access to a nearby bus depot. An ANPR-based enforcement camera was already in place, but despite extensive tuning and relocation, it had not delivered the performance the London Borough of Ealing required.
The council invited Kiowa Systems to demonstrate a different approach. To allow a direct comparison, a MetroVision Unattended Outstation was installed on the same enforcement column as the incumbent system.
The solution
Following a detailed site survey, Kiowa Systems installed an Unattended Outstation comprising an overview camera, a vehicle identification camera and a ruggedised edge processor, all mounted on the existing enforcement column. No additional roadside infrastructure was required.
During the survey, Kiowa identified that a bus lane was located beyond the yellow box junction but remained within the overview camera's field of view. To maximise the value of the deployment, Kiowa proposed configuring the system to enforce both yellow box junction contraventions and unauthorised bus lane use simultaneously from the same installation.
Using advanced AI vehicle classification, the Unattended Outstation was able to distinguish authorised and unauthorised vehicles without the need for a predefined whitelist. Instead, the system automatically established a profile of legitimate bus lane users based on observed traffic patterns, reducing administration and accelerating deployment.
Following a training and optimisation period, the council was provided with secure browser-based access to review enforcement activity, monitor system performance and validate contraventions through an intuitive web interface.
Key features
- Full trajectory tracking — Tracks complete vehicle movements through complex junction layouts without relying on number plate recognition.
- Multi-contravention detection — Simultaneously monitors multiple contravention types and generates separate evidence packages for each event.
- Automated evidence generation — Automatically creates evidential video clips, selects optimal close-up images, and applies PII redaction of bystanders and third-party vehicle number plates.
- End-to-end integration — Evidence is automatically enriched with vehicle details provided by the DVLA to complete the evidence pack being sent to the back-office notice processing system.
The results
The system operated simultaneously, detecting both yellow box junction contraventions and unauthorised bus lane use from a single enforcement location.
To independently assess accuracy, the council ran attended enforcement alongside the trial and compared officer observations with MetroVision's detections. The high level of correlation between the two gave the council confidence in the system's accuracy, consistency and operational readiness.
The MetroVision review process also delivered a significant improvement in operator efficiency. Unlike the incumbent solution, which required more manual intervention, MetroVision automatically assembled complete evidence packs for each potential contravention. Operators could then review the evidence and validate cases with a single click, substantially reducing processing effort and increasing productivity.
“The MetroVision Unattended camera has done everything we needed of it, and in addition, it is also doing bus lane enforcement, which previously needed a separate camera. We are extremely impressed with the new technology.”— Pritesh Kalam, Parking Operations Manager, London Borough of Ealing