# Protect Duty and Crowd Management: A Step-by-Step Guide

> Meet Protect Duty with confidence. OnePlan's step-by-step crowd management guide covers risk, capacity, and emergency planning. Stay compliant.

**Published:** 2026-09-26 | **Updated:** 2026-10-31 | **Author:** oneplansync
**URL:** https://www.oneplan.io/articles/protect-duty-crowd-management
**Type:** post

**Categories:** Event safety and compliance

![Protect Duty and Crowd Management: A Step-by-Step Guide](https://oneplan.sites.aigrowthagent.co/wp-content/uploads/sites/80/2026/09/1788789255743-10fdf8fe3ffd-1024x572.webp)

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## Content

*Written by: Paul Foster, Founder, CEO, OnePlan*

## Key Takeaways

Before diving in, here are the key points to remember:

- Protect Duty under Martyn’s Law (UK) and similar global regulations places legal responsibility on event organizers to assess terrorism threats and implement proportionate crowd-management measures.
- Effective crowd management follows a four-stage lifecycle: Planning and Risk Assessment, Implementation, Monitoring and Control, and Review and Improvement. Each stage benefits from accurate, to-scale digital planning tools.
- Zone-by-zone capacity calculations, real-time density monitoring, and clearly separated ingress and egress routes are critical for preventing crowd-crush incidents and meeting regulatory requirements.
- Documented emergency procedures covering evacuation, invacuation, lockdown, and stakeholder communication are mandatory for compliance and must be exportable for inspections and permit applications.
- OnePlan provides the map-based platform and calculators that make Protect Duty compliance achievable, accurate, and demonstrable. [Book a demo today to see how](https://www.oneplan.io/book-demo/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent).

## Understanding Protect Duty and Martyn’s Law

Protect Duty states that those who control publicly accessible locations hold a legal responsibility to assess the risk of terrorism and put proportionate measures in place. In the UK, that principle now appears in statute.

[Martyn’s Law introduces a tiered system](https://www.gov.uk/government/publications/the-terrorism-protection-of-premises-act-2025) based on the number of people expected to be present at the same time:

- **Standard Tier (200–799 People):** Responsible persons must ensure evacuation routes are in place, staff know how to implement a lockdown swiftly, and staff can communicate quickly with the public during an attack.
- **Enhanced Tier (800+ People):** Additional vulnerability-reducing steps are required, such as CCTV, bag-search policies, and vehicle checks where appropriate. Enhanced-tier premises must also notify the Security Industry Authority (SIA) and maintain documented procedures.

The [SIA is the designated regulator for Martyn’s Law](https://gov.uk/government/news/martyns-law-keeping-up-the-momentum) and is developing its notification portal. The implementation period runs for at least 24 months from Royal Assent, so substantive legal duties are expected to come into force around April 2027. The UK’s national terrorism threat level is currently SEVERE, which makes early preparation essential.

The law is named in tribute to Martyn Hett, one of the 22 victims of the 2017 Manchester Arena bombing. The Manchester Arena Inquiry recommended that a Protect Duty be enacted into law, and the Act directly delivers on that recommendation.

Outside the UK, event organizers must follow their own regional frameworks. In the US, for example, the NFPA 101 Life Safety Code sets requirements for crowd managers, exit numbers, and capacity calculations. Always verify the applicable code with your local authority having jurisdiction (AHJ).

## The Four Stages of Crowd Management

Protect Duty crowd management works as a lifecycle rather than a single action. Industry guidance consistently organizes this lifecycle into four stages:

1. **Planning and Risk Assessment:** Identify hazards, assess risks, and determine safe crowd capacity before the event. This includes analyzing venue layout, expected attendance, ingress and egress routes, and terrorism-specific threats. OnePlan’s to-scale maps and crowd capacity calculator support this stage by letting planners visualize spaces and calculate standing crowd capacities before placing any barriers.
2. **Implementation:** Put physical measures in place, including barriers, signage, staffing, and emergency access routes, based on the risk assessment. OnePlan’s drag-and-drop object library lets teams place crowd barriers, fencing, signage, and staff positions accurately on a live map, generating an auto-populated Bill of Quantities so the right infrastructure is ordered.
3. **Monitoring and Control:** Manage crowd flow in real time during the event, with defined density thresholds that trigger pre-planned responses. [The single most important operational control is a named, competent person with genuine authority to stop ingress or pause the event the instant a density trigger is reached.](https://hseblog.com/crowd-management-hazards) OnePlan’s real-time collaboration means every stakeholder works from the same live plan throughout the event.
4. **Review and Improvement:** After the event, evaluate crowd flow data, incident reports, and staff feedback. Update the plan before the next event. OnePlan’s exportable maps and Bill of Quantities provide a documented record that supports post-event review and future permit applications.

Ready to build a compliant crowd management plan? [Book a 15-minute demo to see OnePlan in action.](https://www.oneplan.io/book-demo/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)

## Step-By-Step: Building a Crowd Management Plan That Meets Protect Duty

### Step 1: Conduct a Thorough Risk Assessment

A risk assessment forms the foundation of any compliant crowd management plan. [The HSE’s approach requires a suitable and sufficient assessment of risks to employees and others affected by the work, including the public at events](https://hseblog.com/event-safety-management), underpinned in the UK by Regulation 3 of the Management of Health and Safety at Work Regulations 1999.

Under Martyn’s Law, the assessment should be event-specific and consider:

- Terrorism threats and the venue’s profile as a publicly accessible location
- Overcrowding and crowd crush risks, particularly at pinch points and entry plazas
- Venue layout, including dead ends, narrow corridors, and sloping terrain
- Expected attendance and crowd profile, such as age, mobility, and familiarity with the venue
- Event type and schedule, including peak arrival and departure times

OnePlan’s to-scale, map-based planning environment lets teams visualize the entire site on a live satellite or street map, identify bottlenecks before they exist on the ground, and calculate area sizes instantly. The [Cheese & Chilli Festival uses OnePlan’s crowd area, queue, and evacuation calculators for risk assessments and management plans](https://www.oneplan.io/case-studies/cheese-and-chilli/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent). This shows how digital tools turn risk assessment into documented, defensible plans.

Regional requirements vary, so always check local codes. For example, in California, event organizers must comply with state fire codes that specify maximum occupancy and crowd manager ratios. Always confirm requirements with your local authority having jurisdiction for each event.

### Step 2: Determine Safe Crowd Capacity

Safe crowd capacity is one of the most critical and most frequently underestimated elements in Protect Duty crowd management. [The controlling variable in crowd safety is density, not headcount](https://hseblog.com/crowd-management-hazards). Crowd crush deaths result from compressive asphyxia in dense, near-static crowds, rather than from panic or running.

OnePlan’s crowd capacity calculator lets you outline any standing crowd area on the map and instantly see its safe capacity based on a selectable people-per-square-meter density. Tom Newton of Bearfoot Productions praised OnePlan for helping his team understand event sites, including measurements and capacities.

For estimating arrival flow and exit times, use OnePlan’s free arrival and exit calculators to estimate queue lengths and exit times. These tools estimate queue lengths, queue times, and exit capacity based on exit width, crowd size, and flow rate. These inputs support a defensible capacity plan.

Capacity must be calculated zone by zone, including stage areas, vendor corridors, entry gates, and exit routes, rather than as a single venue-wide figure. [The binding constraint is the lowest-capacity element, usually the narrowest egress route under emergency conditions.](https://hseblog.com/crowd-management-hazards)

### Step 3: Design Crowd Flow and Ingress/Egress

How people enter, move through, and leave your event site matters as much as how many people attend. [The DIM-ALICED framework maps crowd management across six phases: Arrival, Last mile, Ingress, Circulation, Egress, and Dispersal](https://securitymiddleeastmag.com/critical-infrastructure/the-science-of-crowds). This framework encourages planners to design each phase deliberately rather than focusing only on the event itself.

Key design principles for crowd flow include:

- Separate ingress and egress routes to prevent counter-flows
- Remove bottlenecks, dead ends, and narrow pinch points from the layout
- Plan for peak arrival demand rather than average attendance
- Ensure emergency access routes remain clear and unobstructed at all times
- Provide clear wayfinding signage visible before and during the event

OnePlan’s traffic and transport management tools handle road closures, vehicle access points, pedestrian routes, and parking capacity on the same live map. For a marathon in London, for example, you would plan start and finish areas with clearly separated ingress and egress routes to avoid bottlenecks at peak crowd times. [Stadium planned Coventry Moves, an event with over 12 hours of traffic closures, 400 individual closures across 7 procession routes, and 110 stakeholders, using OnePlan’s point-and-click tools](https://www.oneplan.io/case-studies/events-and-safety-how-stadium-managed-traffic-for-one-of-the-uks-biggest-events-in-oneplan/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent). This approach reduced CAD work that previously took a full day for eight maps to just two hours.

### Step 4: Place Staff and Security Effectively

Trained crowd managers and security personnel are a legal requirement in most jurisdictions. The NFPA Life Safety Code specifies a minimum ratio of one trained crowd manager per 250 attendees for events exceeding 250 people. Requirements vary significantly by state and country, so always confirm the applicable ratio with your local fire marshal or AHJ before building your staffing schedule.

OnePlan allows you to place staff as dots on the map, assigning each a name, role, shift times, notes, and equipment. You can also draw patrol routes directly on the plan, giving every team member clear, shareable instructions. The result is a workforce plan that lives inside the same document as the site layout, rather than in a separate spreadsheet that quickly falls out of sync.

![Workforce planning example inside OnePlan: the base layer is a zoomable satellite or street map, and everything placed on it (tents, stages, crowd barriers, toilets, vehicles, staff, signage, routes) stays accurately to scale as you zoom](https://cdn.aigrowthmarketer.co/1780620462793-34a56c1c38c8.png)**Workforce planning example inside OnePlan: the base layer is a zoomable satellite or street map, and everything placed on it (tents, stages, crowd barriers, toilets, vehicles, staff, signage, routes) stays accurately to scale as you zoom**

Large-scale events illustrate why this level of detail matters. [The Betfred Derby Festival at Epsom Downs sees over 100,000 people attend across two days](https://www.oneplan.io/case-studies/how-the-jockey-club-plans-large-scale-racing-festivals-with-oneplan/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent), where precise staff placement and zone management are essential for safety and compliance.

![Festival planning example inside OnePlan: the base layer is a zoomable satellite or street map, and everything placed on it (tents, stages, crowd barriers, toilets, vehicles, staff, signage, routes) stays accurately to scale as you zoom](https://cdn.aigrowthmarketer.co/1780620510054-c5429587ebad.png)**Festival planning example inside OnePlan: the base layer is a zoomable satellite or street map, and everything placed on it (tents, stages, crowd barriers, toilets, vehicles, staff, signage, routes) stays accurately to scale as you zoom**

### Step 5: Plan for Emergencies and Communication

Emergency planning under Martyn’s Law extends beyond fire evacuation. [Invacuation and lockdown are common gaps in existing emergency plans](https://safetyclarity.co.uk/articles/premises/martyns-law-terrorism-protection-of-premises) that Martyn’s Law specifically addresses. A compliant emergency plan must cover:

- Evacuation, moving people out for internal threats such as fire
- Invacuation, moving people to safety inside for external threats
- Lockdown, restricting movement for active threats where movement increases exposure
- Communication protocols, including who can issue announcements and how alerts escalate
- Assembly points, medical provision, and liaison with emergency services

OnePlan lets you create clear, to-scale emergency plans on the same live map as your operational layout. You can mark assembly points, emergency vehicle access routes, and first-aid stations as recognized icons. Real-time collaboration means every stakeholder, from operations to security to medical teams, works from the same current plan throughout the event. Everything is exportable as a high-resolution map for Safety Advisory Group meetings in the UK and for permit submissions.

Documenting procedures remains essential. Under Martyn’s Law, enhanced-tier premises must maintain records of their procedures and be ready for SIA inspection.

## Common Pitfalls in Crowd Management and How to Avoid Them

Even experienced event professionals encounter predictable traps when building crowd management plans. This section highlights the most common pitfalls and shows how OnePlan addresses each one.

**Relying on non-scaled tools.** Plans built in non-scaled tools like PowerPoint, Excel, or static screenshots are unreliable. Objects do not reflect real dimensions. A tent that looks right on screen may be too large on the ground, and a crowd area that appears spacious can be dangerously overcrowded on event day. OnePlan’s base layer is a live, zoomable satellite or street map, and every object placed on it stays accurately to scale at any zoom level.

**Calculating capacity poorly.** Applying a single venue-wide headcount without zone-by-zone analysis ignores the narrowest egress route that limits safe numbers. OnePlan’s crowd capacity calculator lets you outline individual zones and calculate standing capacity at a selectable density, so every area of the site is assessed independently.

**Allowing communication gaps among stakeholders.** When operations, security, traffic, medical, and local authorities each maintain their own separate plan, nobody works from the same picture. [A crowd management plan is a living operational document](https://hseblog.com/crowd-management-hazards) that teams must review and update as conditions change. OnePlan acts as a single source of truth. One live plan means every department works in the same map instead of five different versions.

**Leaving plans static as the event evolves.** Static PDFs emailed back and forth quickly descend into version chaos. OnePlan’s real-time collaboration means changes are visible to every stakeholder the moment they are made. Live view-only links ensure partners always see the latest version without anyone resending files.

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

**Underestimating infrastructure requirements.** Ordering too few barriers, not enough fencing, or the wrong signage creates last-minute scrambles and compliance gaps. OnePlan’s auto-generated Bill of Quantities turns everything placed on the map into an exportable inventory. Draw a line of crowd barriers and OnePlan tells you exactly how many segments to order.

## How OnePlan Helps You Meet Protect Duty

OnePlan is a visual, to-scale platform built for this kind of planning. OnePlan replaces the usual tools such as PowerPoint, Excel, Canva, Photoshop, Google Maps, and static screenshots, none of which are to scale. It also avoids complex CAD software that requires specialist training. Instead, OnePlan gives event professionals a drag-and-drop, map-based environment where every object stays accurately to scale as you zoom.

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

The features that directly support Protect Duty crowd management include:

- **To-scale, map-based planning** on a live satellite or street map, built on leading GIS technology powered by Esri
- **Crowd capacity calculator** for standing crowds, letting you outline any area and instantly see its safe capacity at a selectable density
- **Arrival and exit calculators** for estimating queue lengths and exit times
- **Workforce planning** to place staff as dots, assign roles and shift times, and draw patrol routes
- **Traffic and transport management tools** for road closures, vehicle access, and pedestrian flow
- **Real-time collaboration** so every stakeholder works from the same live plan
- **Bill of Quantities** auto-generated from everything placed on the map, exportable to Excel or CSV for procurement and contractor coordination
- **Exportable, high-resolution maps** up to A0, print-ready, for permits, Safety Advisory Group meetings, and documentation

[Silverstone, home of the Formula 1 British Grand Prix, uses OnePlan to plan more than 50 events a year, achieving a 13x ROI and reducing planning days by 10%](https://www.oneplan.io/case-studies/how-silverstone-planned-the-british-grand-prix-in-oneplan/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent). OnePlan supports events of every scale, from community festivals to the Paris 2024 Olympic Games.

The Beirut Marathon, which plans for 49,000 runners annually, uses OnePlan’s crowd measurement tools to plan how many people fit into each area of the course. As Race Director Ehrabi Nael explains, [“Using OnePlan saved us months of planning. It’s what we were missing!”](https://www.oneplan.io/case-studies/beirut-marathon-planning-streamlined-with-oneplan-seeing-a-75-decrease-in-site-visits/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)

[Ready to create a compliant crowd management plan? Book a 15-minute demo to see OnePlan in action.](https://www.oneplan.io/book-demo/?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)

## Frequently Asked Questions

### What Is Protect Duty?

Protect Duty is a legal obligation for those responsible for publicly accessible locations to consider the threat of terrorism and implement proportionate protective security and crowd management measures to keep the public safe. In the UK, this obligation is codified in the Terrorism (Protection of Premises) Act 2025, known as Martyn’s Law. Similar duty-of-care principles apply in other jurisdictions through local fire codes, health and safety legislation, and industry standards.

### What Is Martyn’s Law?

Martyn’s Law is the UK’s Terrorism (Protection of Premises) Act 2025, which received Royal Assent on 3 April 2025. It introduces a tiered system of requirements based on the number of people expected to be present. As explained earlier, the standard tier covers premises and events where 200–799 people may be present, and the enhanced tier covers 800 or more. Standard-tier premises must have public protection procedures including evacuation, invacuation, and lockdown. Enhanced-tier premises must implement additional vulnerability-reducing measures, notify the SIA, and maintain documented procedures. Substantive legal duties are expected to come into force around April 2027 following a minimum 24-month implementation period from Royal Assent.

### Who Is Responsible for Crowd Management?

The “responsible person” holds the legal responsibility for crowd management and safety. This is typically the individual or organization with control of the premises for the use that makes it subject to the legislation. Under Martyn’s Law, this is the person who has both possession of the premises and the right and ability to make decisions about their management and use. Legal responsibility cannot be transferred to a third party, even if a contractor or security firm delivers crowd management services on the day.

### What Are the Four Stages of Crowd Management?

The four stages are Planning and Risk Assessment, Implementation, Monitoring and Control, and Review and Improvement. Planning and Risk Assessment identifies hazards, assesses risks, and determines safe crowd capacity. Implementation puts physical measures, staffing, and operational plans in place. Monitoring and Control manages crowd flow in real time with defined density thresholds and intervention triggers. Review and Improvement evaluates the event after it concludes and updates the plan before the next one. Each stage supports a proactive safety strategy and directly supports Protect Duty compliance.

### How Do I Calculate Crowd Capacity?

Safe crowd capacity for standing areas is calculated by dividing the usable area of a space by a safe density factor expressed in people per square meter. This calculation must be done zone by zone, not just for the venue as a whole. As noted earlier, the binding constraint is usually the narrowest egress route. OnePlan’s crowd capacity calculator automates this process. Outline any standing crowd area on the map, select a density, and instantly see its safe capacity.

### What Training Do Crowd Managers Need?

Training requirements vary significantly by jurisdiction. In the US, NFPA 101 requires at least one trained crowd manager for assembly occupancies, with additional managers at a ratio of one per 250 occupants once the occupant load exceeds 250. Some states have their own requirements. For example, California’s 2025 Fire Code requires trained crowd managers for gatherings of more than 500 people. In the UK, Martyn’s Law guidance sets out training expectations for staff at qualifying premises and events, while the Purple Guide serves as a broader crowd safety benchmark. Always confirm the applicable requirements with your local authority having jurisdiction or, in the UK, your Safety Advisory Group and the SIA’s published guidance.

### How Can Technology Help with Protect Duty?

Technology like OnePlan helps by providing a single, to-scale, collaborative platform to create accurate crowd management plans. It supports zone-by-zone standing crowd capacity calculations, staff placement and patrol route planning, ingress and egress flow design, and documentation of all procedures in exportable, high-resolution maps. This documentation is essential for demonstrating compliance to regulators, licensing authorities, and Safety Advisory Groups. Because OnePlan is a live, shared plan rather than a static file, every stakeholder, from operations and security to medical teams and local authorities, works from the same current version at all times.

## Read Next

- [Crowd Safety Plan Template for Outdoor Festivals](https://oneplan.io/articles/crowd-safety-plan-template-festival?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)
- [Crowd Management Software Reviews: Planning vs Analytics](https://oneplan.io/articles/crowd-management-software-reviews-2026?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)
- [Best Crowd Management Software for Event Teams](https://oneplan.io/articles/best-crowd-management-software?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)
- [Game Day Crowd Flow Planning: The Complete Stadium Guide](https://oneplan.io/articles/game-day-crowd-flow-planning?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)
- [Event Crowd Density Map Tool: Comparison & Planning Guide](https://oneplan.io/articles/event-crowd-density-map-tool?utm_term=protect-duty-crowd-management&utm_campaign=ai_growth_agent)

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## Citations

- [PowerPoint Alternatives for Emergency Access Maps](https://www.oneplan.io/articles/best-powerpoint-alternatives-emergency-maps)
- [Canva Alternatives for Emergency Access Planning Maps](https://www.oneplan.io/articles/best-canva-alternatives-emergency-maps)
- [Does Martyn’s Law Apply in the US? What Venues Face Instead](https://www.oneplan.io/articles/does-martyns-law-apply-us)
- [Martyn’s Law for Council Events: A Portfolio-Scoping Guide](https://www.oneplan.io/articles/martyns-law-city-council-events)
- [Martyn’s Law: The Evidence Playbook for UK Venues and Events](https://www.oneplan.io/articles/martyns-law-compliance-guide)

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