How To Plan Martyn’s Law Road Closures: A Step-By-Step Guide

How To Plan Martyn’s Law Road Closures: A Step-By-Step Guide

In this article:

Written by: Paul Foster, Founder, CEO, OnePlan

Key Takeaways

  • Martyn's Law (Terrorism (Protection of Premises) Act 2025) does not automatically require road closures. Enhanced Tier events (800+ people) must complete risk assessments that may identify a need for a Zone-Ex.
  • Road closures for events follow existing highway law, mainly Section 16A of the Road Traffic Regulation Act 1984 or Section 21 of the Town Police Clauses Act 1847, rather than Martyn's Law itself.
  • Organizers should start early, typically 6 weeks to 6 months ahead, complete terrorism risk assessments, apply for Temporary Traffic Regulation Orders (TROs), and work with Safety Advisory Groups (SAGs).
  • Successful road closure planning relies on clear, to-scale maps that show barriers, signage, diversion routes, and emergency access in a format councils and SAGs can approve.
  • OnePlan gives UK event organizers a visual, to-scale mapping platform to produce compliant road closure documentation. See how OnePlan can support your Martyn's Law road closure planning in a free 15-minute demo.

Martyn's Law Overview For Event Planners

Martyn's Law is named in tribute to Martyn Hett, one of the 22 victims of the 2017 Manchester Arena attack. His mother, Figen Murray OBE, led the campaign that resulted in the Act receiving Royal Assent on 3 April 2025. The law requires those responsible for certain premises and events to take proportionate steps to prepare for and protect the public from terrorist attacks.

The Act establishes two tiers of obligation:

The Act applies across England, Wales, Scotland, and Northern Ireland. Qualifying events, where at least 800 members of the public may be present at the same time and entry is controlled by payment, tickets, or membership, follow the same requirements as Enhanced Tier premises.

How Martyn's Law Relates To Road Closures

Martyn's Law does not automatically require road closures. Under the Enhanced Tier, you must consider the risk of a terrorist attack and put proportionate measures in place. If your risk assessment shows that a pedestrian zone or secure perimeter is needed, road closures may form part of your public protection plan.

The law is based on the principle that a terrorist attack might occur anywhere, so the responsible person must consider appropriate and reasonably practicable measures to reduce the risk of physical harm. Your risk assessment drives the decision about road closures, independent of any statutory mandate to close roads.

Zone-Ex As The Link Between Security And Road Closures

Zone-Ex is a term used by UK counter-terrorism police for the area around a venue or event considered for hostile vehicle mitigation, effectively your exclusion zone. ProtectUK, the police counter-terrorism resource hub, provides general risk management guidance for public venues and events.

Under the Enhanced Tier, you must assess whether a Zone-Ex is appropriate based on your risk assessment. A large outdoor festival may require closure of adjacent roads to create a vehicle-free perimeter that prevents hostile vehicles from approaching crowds. A smaller ticketed event in a contained venue may not justify the same level of intervention. The Home Office and the UK Crowd Management Association both emphasise “reasonable” and “practicable” steps based on risk assessment, rather than fixed prescriptive measures.

The Zone-Ex concept connects your Martyn's Law obligations with your road closure application. Once your risk assessment identifies a need for a vehicle exclusion zone, you begin the road closure process with your local authority's highways team.

How To Coordinate Road Closures With Your Local Council

Road closures for events in the UK follow existing highway law, mainly Section 16A of the Road Traffic Regulation Act 1984 or Section 21 of the Town Police Clauses Act 1847. Martyn's Law changes the security rationale and documentation you bring to that process. Use this practical sequence:

  1. Start Early (At Least 6 Weeks Out, Ideally 3–6 Months): Herefordshire Council requires a minimum of six weeks' notice for a road closure TTRO application. Winchester City Council asks for at least 12 weeks' notice. Lead times vary by authority, so contact your local highways team as soon as you have a confirmed date and venue.
  2. Conduct A Terrorism Risk Assessment: Use Martyn's Law principles to assess the threat and decide whether a Zone-Ex is needed. Document your reasoning clearly. The statutory guidance explains that “reasonably practicable” means proportionate, weighing what can be done against cost, time, and difficulty.
  3. Apply For A Temporary Traffic Regulation Order (TRO): A TRO is a statutory legal document that allows the highway authority to regulate the speed, movement, and parking of vehicles, enforceable by council officers or the police. Your application needs a detailed map of the proposed closure, dates and times, diversion routes, and your risk assessment. Some councils, such as Winchester, require a full Traffic Management Plan with sign locations, barrier placements, diversion routes, and emergency access.
  4. Consult With The Safety Advisory Group (SAG): For larger events, the council may convene a SAG, which includes police, fire, ambulance, highways, and the council. Contact your local authority's SAG at least three to six months before the event. Present your road closure plans and risk assessment so agencies can coordinate and give feedback.
  5. Notify The Public And Stakeholders: Display a public notice of road closure in the vicinity at least five days before the event, and use advance information boards five to seven days prior if the closure will significantly affect drivers, businesses, or residents. Some councils also require Advance Warning Signs at each closure point at least one week, ideally two weeks, before the event.
  6. Plan For Physical Implementation: Use to-scale maps to plan the exact layout of barriers, cones, signage, diversion routes, and emergency vehicle access points. Maintain clear emergency access at all times, with a named person responsible for lifting barriers for emergency services.

Build your road closure plan visually in OnePlan and export the maps your council and SAG expect to see.

The Role Of Safety Advisory Groups In Road Closure Planning

A Safety Advisory Group (SAG) is a multi-agency advisory body, typically including police, fire, ambulance, highways, and the local council, that reviews safety plans for public events. SAGs are a UK-specific feature of the event planning landscape.

At the UK Crowd Management Association's Martyn's Law webinar in June 2026, Home Office and Security Industry Authority representatives confirmed that SAGs should observe how organisations respond to Martyn's Law but cannot insist on extra work beyond the legislation. SAGs remain advisory rather than statutory decision-makers under the Act.

Even so, SAGs provide a crucial forum for coordinating road closures, security measures, and emergency response plans. Herefordshire Council's SAG, for example, helps organisers with planning and management and encourages cooperation between agencies. Engage your local SAG early, share draft plans, and use their feedback to refine your traffic management and security case before submitting your TRO application.

Martyn's Law Timeline For Event Organizers

These dates shape how you plan events over the next few years:

The period between now and Spring 2027 is your opportunity to review event plans, complete risk assessments, build relationships with your local authority and SAG, and prepare documentation. ProtectUK's Martyn's Law resources page offers statutory guidance, infographics, and videos to support you during this implementation window.

Martyn's Law Road Closure Checklist For Organizers

  • Review the official GOV.UK statutory guidance on Martyn's Law.
  • Confirm whether your event falls under the Standard Tier (200–799 people) or Enhanced Tier (800+ people).
  • Complete a terrorism risk assessment to decide whether a Zone-Ex is needed.
  • Contact your local authority's events and highways team early, at least 6–12 weeks before the event, and ideally 3–6 months out.
  • Prepare a detailed, to-scale map of proposed road closures, barrier placements, diversion routes, and alternative pedestrian routes.
  • Engage with your local Safety Advisory Group.
  • Apply for a TRO with ample lead time, including your risk assessment and Traffic Management Plan.
  • Plan barrier placement, signage, and emergency vehicle access on your site map.
  • Notify affected residents and businesses and erect advance warning signs within required timeframes.
  • Record all decisions for compliance and future reference.

How OnePlan Supports Martyn's Law Road Closure Planning

The most time-consuming part of this process is often the detailed, to-scale documentation that councils, SAGs, and TRO applications require. Traditional approaches using PowerPoint, Excel, Canva, Photoshop, Google Maps, or static screenshots usually produce layouts that are not to scale. They cannot be edited collaboratively in real time, and they fragment into emailed versions that quickly go out of date. CAD software offers precision but demands specialist training that many event teams lack.

OnePlan provides a browser-based, drag-and-drop mapping platform built for event and operations teams. Its base layer is a live, zoomable satellite or street map. Every object you place, such as crowd barriers, cones, signage, access points, and vehicle exclusion zones, stays accurately to scale as you zoom. You can outline any area and instantly see its dimensions, plan pedestrian and vehicle routes, and calculate standing crowd capacities for each zone.

With OnePlan, you can place barriers, tents, and more inside its integrated, live planning tool

For road closure planning, OnePlan lets you:

  • Drag and drop barriers, cones, and signage onto a live street map to build your Traffic Management Plan.
  • Draw and measure Zone-Ex perimeters and pedestrian exclusion zones to scale.
  • Plan emergency vehicle access routes with accurate clearance widths.
  • Collaborate in real time with your local authority, SAG, police, and traffic management contractors, all working from the same live plan.
  • Export high-resolution maps, up to A0 and print-ready, for TRO applications and SAG presentations.
  • Generate a Bill of Quantities that shows exactly how many barrier segments, cones, and signs you need.

To see how these features work at scale, consider the Tour of Britain, an 8-stage, 1,352 km national road race. The organisers reduced site visits by 75%, saved more than 300 hours a year, and achieved a 3x ROI by coordinating every stage in OnePlan and sharing a self-serve visual plan with suppliers, partners, and authorities.

The clearest demonstration of OnePlan's value for complex road closures comes from Stadium, a UK security and traffic management firm. Stadium used OnePlan to plan Coventry Moves, a 12-hour event with roughly 400 road closures across 7 procession routes and 110 stakeholders. Sign placement time dropped from 5 minutes per sign to under a minute, and CAD work that previously took a full day for eight maps now takes two hours. As Sam Wilson, National Operations Manager at Stadium, said, “If we compare it to CAD, OnePlan works much better for our needs… It would take me a day to do eight maps in CAD. In OnePlan, it's just 2 hours.”

Build your event as a team inside OnePlan: design and manage any physical space on one integrated, live plan

Book a free 15-minute demo to see how OnePlan can streamline your Martyn's Law road closure planning.

Frequently Asked Questions About Martyn's Law And Road Closures

What Is Martyn's Law?

Martyn's Law is the common name for the Terrorism (Protection of Premises) Act 2025. It requires those responsible for certain public venues and events to implement proportionate protective security measures, such as evacuation procedures, lockdown plans, and staff training, to reduce the risk of harm in a terrorist attack. The law applies across England, Wales, Scotland, and Northern Ireland and received Royal Assent on 3 April 2025, with enforcement expected in Spring 2027.

Does Martyn's Law Require Road Closures?

Martyn's Law does not automatically mandate road closures. Under the Enhanced Tier, where 800 or more people may be present, the responsible person must complete a risk assessment and implement proportionate security measures. If that assessment identifies a need for a vehicle exclusion zone, known as a Zone-Ex, around the event perimeter, road closures may form part of the response. Your risk assessment, rather than a blanket legal rule, drives this decision.

What Is The Enhanced Tier Under Martyn's Law?

The Enhanced Tier applies to premises and qualifying events where at least 800 people may be present at the same time. In addition to the basic public protection procedures required of all in-scope venues, Enhanced Tier responsible persons must assess vulnerability to a terrorist attack and take reasonably practicable steps to reduce it. These steps can include CCTV, bag searches, vehicle checks, and, where the risk assessment supports it, hostile vehicle mitigation measures such as road closures and barriers.

What Is A Temporary Traffic Regulation Order?

A Temporary Traffic Regulation Order (TRO) is a statutory legal document issued by a local highway authority that restricts or closes a road for a limited period. For events, TROs are usually made under Section 16A of the Road Traffic Regulation Act 1984 or Section 21 of the Town Police Clauses Act 1847. They provide the legal mechanism that makes a road closure enforceable. Applications go to the relevant local authority, typically the council's highways or events team, with sufficient lead time, a detailed Traffic Management Plan, and supporting maps and risk assessments.

What Is A Safety Advisory Group?

A Safety Advisory Group (SAG) is a multi-agency advisory body in the UK, usually including representatives from the local council, police, fire service, and ambulance service. SAGs review safety plans for public events and provide guidance on safety, emergency response, and traffic management. They are advisory under Martyn's Law and cannot impose requirements beyond the Act, but for larger events they are the main forum for coordinating security and traffic management plans across agencies.

How Can I Plan Road Closures For My Event?

Begin by contacting your local authority's highways or events team as early as possible, at least 6 to 12 weeks before the event, and ideally 3 to 6 months out for larger closures. Complete a terrorism risk assessment to determine whether a Zone-Ex or vehicle exclusion zone is needed. Then apply for a Temporary Traffic Regulation Order, submitting a detailed Traffic Management Plan with to-scale maps of the proposed closure, barrier and signage placements, diversion routes, and emergency access arrangements. Engage your local Safety Advisory Group to coordinate across agencies. OnePlan's browser-based mapping platform lets you build this documentation to scale, collaboratively, and in print-ready formats without specialist CAD skills.

Plan Safe Events With Confident Road Closures

Martyn's Law raises the standard for how you plan security, including decisions about vehicle access, Zone-Ex perimeters, and the reasoning behind each traffic management choice. The accuracy, detail, and defensibility of your plans now matter more than ever.

OnePlan gives UK event organizers, venue operators, and local government events teams a visual, to-scale planning platform that meets this standard. You can drag and drop barriers onto a live street map, plan diversion routes, and export print-ready plans for TRO applications and SAG presentations. The same platform already supports the Tour of Britain, Stadium, and local councils across the UK, and your first event is free to plan.

Start your first event in OnePlan at no cost or book a 15-minute demo to see the platform in action.

Read Next

Start planning your next event

Your first 25 objects are free

Start Planning your Event Site