Chiltern/Aylesbury
Last updated 25 May 2026
Merehead Quarry to Wembley via Westbury, Reading, Princes Risborough, Aylesbury, and Quainton Road — the primary corridor for Mendip limestone and aggregates traffic to North London consolidation centres.
| NR route | Western / North West & Central |
| Route chain | Merehead Quarry – Westbury – Reading – Princes Risborough – Aylesbury – Quainton Road – Wembley European Freight Terminal |
| Key constraints | Westbury area; Reading West curve; Aylesbury single-line section |
| Trailing 12-period A2F | Fewer than 12 closed periods of clean data on record — available once the pipeline reaches 12 complete periods. |
Latest period summary
Chiltern/Aylesbury recorded 70% A2F punctuality in Period 2 2026-27 (26 April – 23 May 2026) on 1,005 freight services, down 2 percentage points from 72% in Period 1 2026-27 on a smaller denominator. The intervals overlap with the prior period. PRELIMINARY at T+2; FINAL re-publication at T+35 after Network Rail's batch correction.
Reports
Operators active
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
The Chiltern/Aylesbury corridor carries Mendip limestone and aggregates from the Somerset quarries — principally Merehead and Whatley — to the North London consolidation centres at Wembley and Acton via Westbury, Reading, and the Chiltern route through Aylesbury and Quainton Road. The corridor also carries HS2 construction aggregates flows.
Capacity at Westbury, the Reading West curve, and the single-line section north of Princes Risborough through Aylesbury and Quainton Road shape the pathing of stone trains across the route.