Westbury Aggregates Terminal — Period 2 2026-27 (26 April – 23 May) report
Westbury Aggregates Terminal handled 135 monitored inbound services and 138 monitored outbound services in Period 2 2026-27. Inbound arrivals read 88% within 15 minutes of schedule against a national freight benchmark of 90%; outbound services read 85% within 15 minutes. The +2 percentage-point move on Period 1 2026-27 inbound and the -7 percentage-point move outbound sit within plausible sampling variation at these denominators; the ranges around each reading overlap. PRELIMINARY at T+2; FINAL re-publication at T+35 after Network Rail's batch correction.
- Edition
- v1.0 (industry review edition)
- Last updated
- 25 May 2026
- Next update
- Period 3 2026-27 — late June 2026
Headline facts and figures
Services monitored (inbound)
135
queried gauge_intelligence_v2 at 2026-05-25; across the four Westbury tiplocs (WSTBLAF, WSTBRDY, WSTBRUY, WSTBRYW); Period 2 2026-27 (26 Apr – 23 May 2026); NROD-derived arrivals data; baseline 130 services in Period 1 2026-27
Within 15 minutes (inbound)
88%
queried gauge_intelligence_v2 at 2026-05-25; 119 of 135 completed inbound services arriving within 15 minutes of schedule (range 83–92% given the sample size); baseline 86% [80–91%] over 130 completed services in Period 1 2026-27 — ranges overlap; national freight benchmark 90% over 11,130 services in Period 2 2026-27
Services monitored (outbound)
138
queried gauge_intelligence_v2 at 2026-05-25; across the four Westbury tiplocs (WSTBLAF, WSTBRDY, WSTBRUY, WSTBRYW); Period 2 2026-27 (26 Apr – 23 May 2026); NROD-derived departures data; baseline 156 services in Period 1 2026-27
Within 15 minutes (outbound)
85%
queried gauge_intelligence_v2 at 2026-05-25; 117 of 138 completed outbound services departing within 15 minutes of schedule (range 79–90% given the sample size); baseline 92% [88–95%] over 156 completed services in Period 1 2026-27 — ranges overlap; national freight benchmark 90% over 11,130 services in Period 2 2026-27
Context
ORR publishes aggregates only; this page publishes site-attributed supply-chain data with inbound and outbound directions reported separately. Material to bulk-flow planning, terminal siding allocation, and corridor performance reviews.
What you can do with it
- Track inbound arrivals and outbound departure reliability at a single supply-chain site.
- Compare operator-by-operator reliability on services to and from the Westbury terminal cluster.
- Cite the methodology in aggregates planning and corridor reviews.
Who can use it
Terminal operators · Aggregates planners · Rail journalists
Across Period 2 2026-27, roughly inbound trains a day arrived at Westbury Aggregates Terminal more than 15 minutes late and roughly outbound trains a day departed more than 15 minutes late, across 135 completed inbound arrivals and 137 completed outbound departures over the 28-day period. Inbound within-15-minutes arrivals read — against 86% in Period 1 2026-27, a +2 percentage-point move; outbound read — against 92%, a -7 percentage-point move. The ranges around each reading overlap, so neither move clears the threshold for a defensible step change on this sample size. Monitored journeys moved from 130 inbound and 156 outbound in the baseline to 135 and 137 respectively; counting journeys by site does not separate timetable change, traffic mix, or absent operators from underlying demand, and this report does not attribute the movement to a specific cause. Figures aggregate every monitored journey at the four Westbury tiplocs in Network Rail's NROD/TRUST feed. Cancellations are reported separately below.
Inbound — services arriving at Westbury Aggregates Terminal
Operators at Westbury inbound
Colas Rail ran the most westbury inbound services in Period 2 2026-27 (45 of 135 completed arrivals). The full per-operator reliability comparison is deferred while the v1.0 industry review edition corrections inbox remains open.
Publishing a per-operator on-time comparison for the busiest freight operators at a single destination before the launch-cohort corrections cycle closes would treat provisional attribution as settled. The table returns at v2.0 general availability. The league-table methodology documents the comparison framework; the release cadence page sets out the four exit criteria for v2.0.
Source: Gauge Intelligence NROD-derived journey data, Period 2 2026-27. Single-destination headline figures (completed arrivals, aggregate within-15-minute rate, cancellations) continue to appear in the panels above; the per-operator breakdown is the panel deferred here.
What the 15-minute threshold hides
Half of Period 2 2026-27 services arrived early — the median was 4 min ahead of timetable. The long tail the A2F binary misses: 5% of services ran +66 min or more late, and 1% arrived over +130 min late. The 15-minute A2F threshold sits at the 88th percentile — 12% of services exceeded it.
Median arrival delay is 3 minutes later than Period 1 2026-27 (median was -7 min then, -4 min now).
| Percentile | Arrival delay |
|---|---|
| 50th percentile (median) — A2F threshold sits at the 88th percentile | -4 min |
| 75th percentile — A2F threshold sits at the 88th percentile | +3 min |
| 85th percentile — A2F threshold sits at the 88th percentile | +10 min |
| 90th percentile | +19 min |
| 95th percentile | +66 min |
| 99th percentile | +130 min |
135 services with confirmed terminal arrival in Period 2 2026-27. A2F is binary at 15 minutes — this distribution surfaces what the headline figure does not show. National 99th percentile across all freight operators: 95 min.
Baseline (Period 1 2026-27): median -7 min, p99 +96 min. Period-on-period median shift +3 min.
ORR's Freight rail usage and performance release publishes by Network Rail region and route, not by operator. This page publishes by operator and corridor.
Cancellation rate
No scheduled paths or activated journeys recorded for Period 2 2026-27.
Outbound — services departing from Westbury Aggregates Terminal
Operators at Westbury outbound
Freightliner Intermodal ran the most westbury outbound services in Period 2 2026-27 (50 of 137 completed arrivals). The full per-operator reliability comparison is deferred while the v1.0 industry review edition corrections inbox remains open.
Publishing a per-operator on-time comparison for the busiest freight operators at a single destination before the launch-cohort corrections cycle closes would treat provisional attribution as settled. The table returns at v2.0 general availability. The league-table methodology documents the comparison framework; the release cadence page sets out the four exit criteria for v2.0.
Source: Gauge Intelligence NROD-derived journey data, Period 2 2026-27. Single-destination headline figures (completed arrivals, aggregate within-15-minute rate, cancellations) continue to appear in the panels above; the per-operator breakdown is the panel deferred here.
What the 15-minute threshold hides
Half of Period 2 2026-27 services arrived early — the median was 2 min ahead of timetable. The long tail the A2F binary misses: 5% of services ran +48 min or more late, and 1% arrived over +87 min late. The 15-minute A2F threshold sits at the 85th percentile — 15% of services exceeded it.
Median arrival delay is 1 minutes earlier than Period 1 2026-27 (median was -1 min then, -2 min now).
| Percentile | Arrival delay |
|---|---|
| 50th percentile (median) — A2F threshold sits at the 85th percentile | -2 min |
| 75th percentile — A2F threshold sits at the 85th percentile | +5 min |
| 85th percentile — A2F threshold sits at the 85th percentile | +10 min |
| 90th percentile | +29 min |
| 95th percentile | +48 min |
| 99th percentile | +87 min |
137 services with confirmed terminal arrival in Period 2 2026-27. A2F is binary at 15 minutes — this distribution surfaces what the headline figure does not show. National 99th percentile across all freight operators: 95 min.
Baseline (Period 1 2026-27): median -1 min, p99 +71 min. Period-on-period median shift -1 min.
ORR's Freight rail usage and performance release publishes by Network Rail region and route, not by operator. This page publishes by operator and corridor.
Cancellation rate
No scheduled paths or activated journeys recorded for Period 2 2026-27.
What this report doesn't yet carry
Four blocks routinely carried on more mature period reports remain absent, and the gap is disclosed rather than papered over:
- Partial-pool operator league table. The supply-chain artefact track is not yet wired into the archive renderer — the partial-pool, median-polish, statistical process control (SPC), and compositional log-ratio panels do not yet emit for supply-chain sites. Inbound and outbound flows at a terminal cluster behave as two distinct populations and the partial-pool shrinkage assumption needs separate calibration for each direction. The block is suppressed pending that calibration.
- SPC process-behaviour chart. Westbury has eight weekly A2F (arrivals-to-fifteen-minutes) points per direction across Period 1 and Period 2 2026-27 combined. The signal rules require eight before a stability or anomaly claim can be made — the threshold is now met; the chart enters as a candidate from Period 3 2026-27 once the baseline survives one more period without composition change.
- Median-polish operator-by-week matrix. The operator mix at Westbury spans four carriers but the weekly cell counts per operator are below the minimum-journeys threshold, so the row-by-column matrix degenerates and no decomposition is published.
- Compositional delay-reason breakdown. Network Rail's Historic Delay Attribution (HDA) feed for Period 2 2026-27 has not been imported at the as-of date of this report. Raw percentage-share comparison is misleading when shares are constrained to sum to 100% — an increase in any one cause forces a decrease in another — so the block is suppressed rather than substituted with a naked share. See the delay-attribution methodology.
Each of these unlocks as baseline depth grows. The weekly SPC threshold is met from Period 3 2026-27; the operator-by-week matrix and HDA breakdown become candidates as the trailing window deepens through 2026-27.
Methodology & sources
All figures derive from Network Rail's NROD TRUST feed, processed via the Gauge Intelligence ingest pipeline. Period definitions, A2F (Arrival to Fifteen), the Wilson 90% interval, daily anomaly rules, cross-view reconciliation, and delay attribution are documented at:
Data window — period boundaries and the data-as-of cutoff
League tables — cross-view reconciliation across the four analytical views
Anomaly detection — daily A2F SPC rules
Delay attribution — DAPR cause-code breakdown
Forecasting — prediction intervals and possession-exposure estimates
Three further reads sit behind the commercial licence: a Schedule 8 net-position figure netting the FOC-to-Network-Rail differential against payments the other way; a full Delay Attribution Performance Report breakdown attributing each cause-code's contribution by sample weight; and a Schedule 4 possession-exposure read tracing how planned blockades intersect terminal-bound path allocation. None is yet substantively informative at Westbury's current baseline depth — the period count that suppresses the SPC chart above leaves each licensed read with too few points to anchor. The licensed access page sets out the methodology behind each.
Revisions
No revisions to date.
A revision restates a published figure because the upstream data changed, typically a Network Rail delay-attribution refresh. The minor tier is corrected in the next release; cells affected carry an (r) flag. The intermediate tier triggers immediate amendment with an (r) flag. The wholesale tier is flagged at the top of the page and notified directly to operators and rail journalists subscribed to revision alerts.
Corrections
No corrections to date.
A correction fixes an error in the published output: an arithmetic slip, a typo, a mis-rendered chart. Revisions are different; they restate a figure because the upstream data changed. The distinction matters because corrections never silently rewrite a published number.