On 4 November 2025 the Secretary of State made the A122 (Lower Thames Crossing) Development Consent (Amendment) Order 2025 (S.I. 2025/1161), which comes into force on 5 November 2025. The instrument implements a non‑material change under paragraph 2 of Schedule 6 to the Planning Act 2008 following publicity and consultation carried out under regulations 6 and 7 of the 2011 Change Regulations. It amends the A122 (Lower Thames Crossing) Development Consent Order 2025 (S.I. 2025/462, corrected by S.I. 2025/1014).
The amendment substitutes the text of commitment HR013 in the Register of Environmental Actions and Commitments within the Code of Construction Practice. The revised commitment requires appropriate technology and infrastructure to enable the enforcement authority to enforce a 60mph speed limit in the westbound direction on the M25 between junctions 26 and 27. National Highways must provide reasonable and appropriate funding to the relevant highway and enforcement authority to set the limit and undertake enforcement.
The purpose of the measure is to avoid an Adverse Effect on Integrity on Epping Forest Special Area of Conservation arising from in‑combination air quality effects attributable to traffic emissions, specifically nitrogen deposition and concentrations of NOx and NH3. The change places the control directly within the project’s environmental commitments rather than as a separate, later decision point.
The Order specifies timing. The 60mph measures are to be in place from the commencement of operation of the Lower Thames Crossing. This makes the control an operational mitigation linked to opening, not a temporary construction‑phase restriction.
Monitoring obligations are expanded and time‑bound. Monitoring must commence no later than six months after construction of the scheme begins and remain in place for a minimum of four years after commencement of operation. The programme must monitor NOx, NO2 and NH3, with results used to determine vehicle‑emission‑related nitrogen deposition against pre‑operation values.
Annual reporting is required and must include a review of relevant evidence such as monitoring outputs, traffic data and regional pollution, in consultation with Natural England. This embeds an evidence cycle into delivery and operation, aligning with the conservation objectives for the Epping Forest SAC.
A review mechanism is included. The Secretary of State may, upon receipt of a written request from National Highways that has been informed and agreed through consultation with Natural England, determine that the measures are not required at or after opening to prevent an AEoI, having regard to pre‑operation monitoring and any additional assessment. If monitoring and updated modelling indicate increases in nitrogen deposition and/or NOx and/or NH3 that would lead to an AEoI, the speed limit control and enforcement must be in place unless otherwise agreed with Natural England.
For delivery teams, the immediate tasks are to update control documents to reflect the revised HR013 text, plan and procure enforcement‑enabling infrastructure, and agree funding and operational arrangements with the relevant highway and enforcement authority. Environmental management systems should schedule the monitoring start within six months of construction and the four‑year post‑opening programme with annual reporting dates.
For planners and legal advisers, this confirms use of the non‑material change route to strengthen mitigation without reopening the full DCO. The Secretary of State notes consideration of consultation responses before making the Order, indicating that the change remains within the existing development envelope while clarifying enforceable commitments in the Code of Construction Practice.
The instrument is signed by Kayla Marks, Head of the Transport and Works Act Orders Unit at the Department for Transport, dated 4 November 2025. As of 5 November 2025, the amendment has legal effect and forms part of the A122 (Lower Thames Crossing) Development Consent Order 2025 control framework as amended.