443.1 Inputs to the decision

Collect VDA outputs, approach speeds, angles, people proximity, and frontage sensitivity (221–225, 231, 234). These inputs decide if an HVM bollard is necessary or a crash rated bollard lane is justified.

Start by summarizing your VDA findings: run-up distance, likely impact angle, and vehicle class. Combine this with people proximity around frontages and entrances.

Translate the above into an initial “energy tier” using your speed band estimate (see 443.8 quick-check). If the energy sits near the boundary between low-speed and HVM, adopt a margin of safety and plan an early reviewer conversation using the Decision Flow.

443.2 Site threat context

Document credible threats, asset value, and authority posture (133, 212). Context anchors whether low-speed suffices or an HVM bollard is mandated.

Use a brief threat scenario note and a stand-off sketch. If your DBT includes deliberate attack, low-speed options (PAS 170-1 / ASTM F3016) are typically not appropriate—escalate to certified crash rated solutions.

For UAE projects, note any SIRA direction. If SIRA requires certified products and evidence, your baseline shifts to HVM with an appropriate purpose→tier justification. Link this rationale in the submission pack (see Submission-Pack Guidance).

443.3 People proximity & glazing

Close crowding and brittle glazing raise injury/penetration risk (231, 234). Proximity often tips selection to a crash rated bollard line.

Where queues form near glass, even “benign” roll-throughs can cause harmful penetration. Favor continuous arrays with clear-gap checks and near-door spacing tuned to the defend line.

Consider glazing upgrades and set-backs, but don’t rely on them as substitutes where the threat or energy suggests HVM. Use frontage protection patterns and show capture height and rhythm in your drawings.

443.4 Vehicle access & speeds

Open perimeters, long run-ups, and delivery lanes increase energy (214, 222). Higher energy pushes toward HVM bollard solutions.

Map likely approach vectors, including informal “desire lines.” Long, straight run-ups or downhill gradients increase the effective impact speed; traffic calming (speed humps, chicanes) can help but must be enforceable and maintained. Where vehicles legitimately pass, consider automatic HVM lanes with suitable interlocks instead of passive low-speed posts.

If the speed estimate crosses the comfort band of low-speed tests (see 441/442), make HVM the default and justify any deviation with documented controls and reviewer agreement.

443.5 Authority expectations

SIRA/local rules may require certified products and evidence (717). Meeting expectations accelerates crash rated bollard approvals.

Check the applicable reviewer pathway and evidence thresholds early. For the UAE, reference the SIRA Bollards (UAE) hub and plan your authority submittals (certificates, test reports, unedited footage, array/foundation comparability). Align your tender and specification language with anti-downgrade/equivalence clauses to prevent substitutions.

443.6 Lifecycle & costs

Weigh capex vs downtime, repainting, and energy (842, 365). Lifecycle can favor a durable HVM bollard install.

Low-speed options can be cheaper up-front but may dent, loosen, or require frequent repainting after minor bumps. HVM systems have higher capex but offer proven performance, better durability, and lower long-term disruption—especially when paired with good design for maintenance and planned service windows. For automatic lanes, include energy and maintenance budgets; see Lifecycle & maintenance.

443.7 Upgrade triggers

Note incidents, tenant changes, or traffic shifts (118, 446). Triggers justify migrating to a crash rated bollard.

Typical triggers include near-misses, new high-profile tenants, event usage, changed traffic flow, or construction altering approach geometry. Record these in the change log and revisit your VDA report template. If the credible worst case increases, plan the upgrade path to HVM with staged works and interim controls.

443.8 Decision worksheet

Record inputs→tier→array→foundation (235, 321–332). A worksheet defends HVM bollard choices.

Low-Speed Impact Energy Quick-Check (indicative): Use this as a conversation starter, then run the spreadsheet for your exact case from Calculators (920).

Then complete the worksheet: (a) inputs (VDA, proximity), (b) tier selection (low-speed vs HVM rating), (c) array and pattern, (d) foundation class (see foundation types). Keep evidence and assumptions with the submission pack.

443.9 Case examples

Show contrasting sites with IDs and outcomes. Examples clarify when a crash rated bollard is warranted.

Retail frontage: Short run-up, crowding near glazing. Outcome: continuous HVM frontage array with near-door spacing tuned to the defend line.

Service yard with public edge: Mixed flows, occasional long run-up at night. Outcome: automatic HVM lane with interlocks; low-speed posts used only inside the secure area as secondary segregation.

Selecting Low-Speed vs HVM — FAQ