The Supply Chain Safety Leadership Group’s Incursions Working Group, in collaboration with the Traffic Management Contractors Association (TMCA), has published new guidance entitled “Guidance on Additional Measures for Determined Vehicles”.  

The document, which is now available to the industry at TMCA.org.uk, sets out a practical framework for protecting temporary traffic management (TTM) operations from vehicles that persistently breach road closures. Led by Paul Spreadbury of Virtus (part of the HW Martin Group of Companies) and Greg Baldwin of HTM (Highway Traffic Management), the project aims to help the industry assess and respond to worksite incursions using a proportionate, risk-based approach.

“Developing this guidance was a complex challenge due to the sheer number of variables inherent in temporary traffic management,” said HTM’s Baldwin.

“However, the core message we want to share is this: the primary mitigation against determined vehicles is ensuring standard traffic management is correct, compliant, and effective from the outset. Only when that foundation is in place should the secondary measures discussed in this document be applied, following a clear risk-based approach.”

Key Areas Covered in the Guidance

• Defining the Threat: The document distinguishes between a “Determined Vehicle” (persistent, ignoring controls, high momentum) and a “Hostile Vehicle” (driven with malicious intent to cause harm). This distinction helps ensure that appropriate responses are considered.  
• Risk-Proportionate Mitigation: Moving away from an “apply to all” approach, the guidance emphasises the “So far as is reasonably practicable” (SFAIRP) principle, advising that secondary mitigations should be dictated by site-specific risk assessments rather than a default response.  
• Hierarchy of Control: It outlines a 5-tier mitigation categorisation framework: Traffic Delineation, Detection and Alert, Visible Deterrents, Physical Deterrents, and Physical Access Control.  
• Traceability: The guidance highlights the need for contractors to maintain a Mitigation Decision Log and a Risk Classification Record to ensure clear and traceable decision-making processes.  

Following the publication, the Incursions Working Group and the TMCA will begin rolling out briefings to TMCA members and the wider industry. The document also provides a standard framework that product manufacturers can use to help align their future safety products with the practical needs of traffic management operators.

(Picture – TMCA)