Matrix linking purposes to tiers, examples, and product classes.
Choose performance early with a defendable matrix. We align common protection purposes to tiered outcomes—SIRA tiers and global crash rated bollard ratings (123, 411–416)—and flag edge cases that justify overrides. Evidence notes point to VDA inputs (221–229). Use the matrix directly in specs (433), selection flows (339, 432–435), and stakeholder briefings (131, 137). Include one-sentence context that naturally links upward to the parent hubs (this section and the chapter hub). Add SIRA context with a link to SIRA Bollards (UAE) when relevant. Link installation pages only if helpful: What to Expect and Installation Guide.
Important: This is a general guide. For live projects we develop a tailored
Method Statement & Risk Assessment (MS/RA) and align with authority approvals (e.g., SIRA) where in scope.
235.1 Purposes list
List frontage protection, lane control, asset shielding, and crowd safety. Each maps to HVM bollard needs; if certification is required, identify the crash rated bollard class (411–414).
Start with clear purpose language and avoid jumping to product names. Typical purposes include: (a) Frontage protection for doors, glazing, and recesses; (b) Vehicle access control lanes with interlocks; (c) Outdoor asset protection for utilities, kiosks, art, or ATMs; and (d) Public safety in plazas and pedestrianized streets. For each, decide whether you need HVM performance or a low-speed storefront solution (see Low-Speed Impact Ratings).
Where certification is required, tie the purpose to a suitable crash rating and penetration class (see How to read ratings). Use clear-gap calculations to ensure arrays meet the purpose without choking pedestrian flow.
| Aspect | What matters | Where to verify |
|---|---|---|
| Performance | Tested system (bollard + footing) | Crash standards overview |
| Operations | Duty, fail-state, EFO, safety devices & measures | EFO & overrides |
235.2 Tier definition recap
Summarize SIRA light/average/heavy and global speed/mass lines (123). Tiers gate HVM bollard selection and the crash rated bollard rating string (413).
Use the tier concept to translate risk into performance bands. Locally, SIRA (Dubai) distinguishes Light, Average, and Heavy intents for vehicle security barriers. Globally, map these to speed/mass lines from IWA/ASTM families, then express the requirement as a rating string (see reading ratings).
Document the governing DBT, run-up corridor, and impact angle. These anchor your tier choice and prevent later dilution.
235.3 Matching purpose→tier
Frontages near crowds trend higher; service yards may be lower with controls. Assign HVM bollard tiers transparently; pick the crash rated bollard that meets the resulting band.
Work through purpose→tier in three steps: (1) purpose definition; (2) credible vehicles and approach speeds from the VDA method; and (3) selection of a suitable rating band (e.g., IWA 14-1 N2A/C or ASTM F2656 M3). Frontages with high footfall or tight standoff near doors usually demand a higher tier than remote service yards with gates, bollard lanes, and CCTV/ACS controls.
Once the tier is set, choose products that meet it and confirm rating-critical dependencies (footing class, depth, soil, spacing). Bring spacing rules from 232 Spacing rules to avoid pass-throughs.
235.4 Edge cases & overrides
Document when constraints or vectors force a higher tier (216, 225). This can tighten HVM bollard gaps or require a stronger crash rated bollard.
Examples include shallow utilities restricting foundation depth, corner geometries that enable glancing strikes at higher effective speeds, or narrow forecourts that push arrays closer to glazing. In these cases, either raise the tier, adopt deeper/shallow-rail foundations from 244 Shallow foundations, or re-shape the array (see 324 Corners & pinch points).
Record the override in the assumptions register and show the impact on the rating string and spacing tolerance budget.
235.5 SIRA tiers in matrix
Embed SIRA rows with examples (133). HVM bollard tiers align with local expectations; show the crash rated bollard equivalence where valid (414).
For Dubai/UAE projects, present a matrix with SIRA Light/Average/Heavy rows and example use-cases (e.g., mall frontage vs. service yard). Where appropriate, indicate an equivalency to IWA/ASTM bands (see Standards equivalency). Always include a caveat that final acceptance remains with the authority.
Link reviewers to SIRA Bollards (UAE) for local expectations and process timing (see 137 Market-Specific Requirements).
235.6 Evidence notes per mapping
Link each cell to VDA fields (221–229). This shows why HVM bollard counts and the chosen crash rated bollard are appropriate.
Each matrix cell should carry a short “Evidence” note: site photos with vector overlays, run-up length, surface friction, gradient, approach vectors, and sensitivity bands. This lets reviewers reproduce your inputs and reduces debate during witness procedures.
235.7 Upgrade triggers
Call out incidents, policy changes, and crowd growth (446). HVM bollard arrays adapt; a crash rated bollard swap path is listed.
Define triggers that move a site to a higher tier: incident history, special events, change of use, higher footfall, or altered traffic patterns. Link these to a pre-agreed escalation path and product swap strategy (e.g., sleeve-only aesthetic changes vs. full core/foundation upgrades; see 446 Upgrade paths). Keep an evidence pack so decisions are auditable.
235.8 Example matrices
Provide mall, embassy, and hospital samples. HVM bollard arrays and the matching crash rated bollard class are shown.
Mall frontage: High pedestrian density and storefronts near carriageway. Tier: higher band; options include fixed arrays across frontage and automatic lanes for deliveries. Cross-check door protection arrays.
Embassy perimeter: Sensitive asset with formal standoff, controlled approaches, and vetting. Tier: highest band, with emphasis on array resilience and multi-hit scenarios. Consider orientation and impact angles.
Hospital drop-off: Mixed flows and emergency access. Tier: mid to high depending on geometry. Use emergency/service access patterns and turning/lanes to keep response times intact.
235.9 How to use in specs
Paste selected rows into 433 with dependencies (421). Locks HVM bollard intent and binds the crash rated bollard specification.
Take the agreed rows and paste them as a “Performance Tier Schedule” in your specification (see 433 Specification template). Include the rating string, penetration class, rating-critical dependencies, and inspection hold points. Reference the VDA report (229) and drawings for array geometry and clear gaps.
Related
External resources
- NPSA: Hostile Vehicle Mitigation (HVM) — guidance
- FEMA 426 / DHS: Reference Manual — Mitigating Attacks
- ASTM F2656: Vehicle Crash Testing Standard
235 Purpose/Tier Matrix — FAQ
How do I pick a tier if my site has both storefronts and a service yard?
Split by purpose. Apply a higher tier to crowds/frontages and a lower tier to gated service areas if controls limit approach speed. Document the split with VDA evidence and reflect it in array spacing and rating strings.
What if utilities prevent the tested foundation depth?
Use shallow foundation families tested for equivalent performance (e.g., shallow-rail). If that is not feasible, raise the tier or redesign the array. Record the change as an override and cite rating-critical dependencies in the spec.
Can SIRA “Light/Average/Heavy” be mapped to IWA or ASTM directly?
Use equivalency cautiously. Show the speed/mass/penetration intent and reference IWA/ASTM rating bands as guidance, with final acceptance by the authority. Always include a note on any assumptions and local policy updates.
When should we revisit the matrix after handover?
Reassess after incidents, policy changes, special events, or sustained crowd growth. Maintain an evidence pack and an escalation path so upgrades (e.g., product swap or spacing changes) can proceed quickly.