Committee publication · Correspondence · 22 October 2025

Letter from National Highways relating to oral evidence received by the committee on the 3 September 2025, dated 30 September 2025

From: Environmental Audit Committee

Inquiry: National Highways and environmental sustainability

Summary

National Highways' Chief Executive Nick Harris writes to clarify points from oral evidence to the Environmental Audit Committee on 3 September 2025, specifically addressing A14 tree-planting funding and ORR oversight. The letter details lessons learned from poor tree survival rates on the A14, outlines a revised replanting strategy, and provides progress updates on the organisation's broader Environmental Sustainability Strategy, including biodiversity, water quality, air quality, net zero, and noise mitigation initiatives.

Key findings

  • A14 tree-replanting costs were absorbed within existing National Highways public funding, not separately requested; future replanting would come from Road Investment Strategy allocations.
  • Primary causes of A14 tree failure identified: bareroot rootstock choice, drought conditions, sub-optimal soil nutrients, and inadequate aftercare maintenance.
  • Replanting strategy now incorporates cell-grown trees, mulching, targeted fertilisers, enhanced maintenance regimes, larger initial tree sizes, biodegradable guards, and adapted species selection for embankments.
  • National Highways delivered 6,744 biodiversity units against a 6,148 target (596-unit net gain) by end of 2024/25; Network for Nature partnership with Wildlife Trusts completed four phases across 51 locations, delivering 3,688 biodiversity units.
  • Water quality improvements ongoing with 16km of waterbody enhanced and 1,236 high-priority drainage assets validated; risk-based approach focuses resources on high-risk outfalls, with approximately 250 locations identified for intervention.

Tone

Procedural

Topics

environmental-sustainabilitybiodiversitywater-qualitytree-plantingnet-zero

Key actors

Nick Harris, Toby Perkins MP, National Highways, Environmental Audit Committee, The Wildlife Trusts, Office for Rail and Road

Notable line

… we have not yet delivered the environmental outcome we set out to, and we are determined to address that.

Key Quotes

I accept that we have not yet delivered the environmental outcome we set out to, and we are determined to address that.
Nick Harris · Acknowledging A14 tree-planting performance shortfall
… the costs have been met by National Highways from public funds, so I am keen to correct any misunderstanding of my evidence.
Nick Harris · Clarifying A14 replanting funding source
We believe that investment in infrastructure is good for the economy and good for the environment, providing an opportunity to invest in and work with nature.
Nick Harris · Broader environmental sustainability commitment
Early indications are that the re-planting strategy is delivering improved results, and we will continue to maintain the young trees for a five-year establishment period in line with best practice.
Nick Harris · Progress on revised A14 tree strategy
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Source · parliament.uk record ↗

Letter from National Highways relating to oral evidence received by the committee on the 3 September 2025, dated 30 September 2025 | Beyond The Vote | Beyond The Vote