Clearview Intelligence - Smart Mobility Solutions

Case Studies

Cawood Swing Bridge Weight Restriction Monitoring System

A weight restriction in place to protect the Cawood swing bridge and only vehicles weighing less than 7.5t are permitted to cross the bridge. Clearview Intelligence provided a unique and sustainable system to monitor use of the bridge and alert the client of any overweight vehicles using the bridge.


Cawood Bridge is a swing bridge which spans the River Ouse in North Yorkshire, England. Constructed in 1872, the Cawood Bridge is now a Grade II listed building. In recent years the bridge has undergone major structural repair work. To protect this important structure there is a weight restriction in place and only vehicles weighing less than 7.5 tonnes are permitted to cross the bridge.

To ensure that heavy goods vehicles were deterred from using the Cawood Bridge, North Yorkshire County Council had relied on a weight restriction system coupled with Automatic Number Plate Recognition (ANPR) and this system had been in place for over a decade. Given the age of the technology and its bespoke nature, a decision was made by the Council in 2015 to replace the legacy system completely.


Clearview Intelligence, who provided the original system, was approached by the Council to design a unique, sustainable replacement, utilising the latest camera and cloud based software, supported by an ongoing maintenance service. 3M were invited to collaborate on the provision of new ANPR cameras and software to integrate with data collected via Clearview’s M720 Vehicle Count Classifier.

The new system does not actually weigh vehicles, but instead is based on a ‘length of vehicle’ trigger threshold, as captured by the M720. Dual ANPR cameras are triggered following length classification, and images of offending vehicles are captured as they cross the bridge. All image capturing is overlaid with an accurate date and timestamp. The cameras transmit live data via ADSL modem to cloud servers which run ‘portal’ software.

The client can view each captured event and determine if the vehicle warrants further investigation. Those vehicles considered to be offending are exported to the necessary authority to check against DVLA records. The image system has NAAS certification (Home Office approved National ANPR standards) and ensures reliable prosecution of any offenders.

The complete system can be accessed remotely using the portal and VPN tunnel, enabling the support team to undertake daily health checks and preventative maintenance, and to respond instantly to any faults to ensure continued operation. As an added benefit to the client, all vehicles crossing the bridge are classified by the M720 and fed live to our Insight data intelligence platform.

This system enables the client to access all vehicle data from a personal account where they can view an array of graphical and tabular data reports including traffic flow, total count, class, speed, and peak traffic graphs. The client can review traffic flows across any user-defined period of time and this data provides essential intelligence for decisions relating to the ongoing maintenance and upkeep of this historic structure.

The robustness of the system was put to the test just weeks after installation when the River Ouse flooded the bridge in December 2015. Despite the extensive water damage to infrastructure and buildings around the bridge, the system had been carefully installed above even the unprecedented flood level and, once the waters receded and the mains electricity supply was restored, the system was fully operational again.

Key Benefits

  • More cost effective option than Weigh in Motion systems, with lower installation and operational costs
  • Remote access enables daily health checks and allows an instant response to faults to ensure continued operation
  • Provides vital usage intelligence to inform maintenance and repair decisions
  • Restricting image capture to only include offending vehicles speeds up data processing and enables a speedier reaction to any contraventions
  • Enables client to effectively pursue motorists who ignore the weight restrictions in place and deters repeat offenders, reducing the risk of further structural damage

Insight Count and Classify

An integrated data management solution designed to support accurate and timely decision-making by ITS professionals. Insight Count and Classify comes with a suite of tools focused on optimising service delivery and the effective use of the road capacity. Insight eases the burden of remote data collection, device management, data processing, reporting and analysis.