One Plan, Two Rule Books: Applying GB Domestic and Assimilated Drivers’ Hours in a TMS in 2026

GB drivers’ hours rules for goods vehicles come in two sets: the assimilated rules, formerly the retained EU rules, which cover most goods vehicles over 3.5 tonnes and journeys between the UK and the EU, and the GB domestic rules, which cover most goods vehicles that are exempt from the assimilated rules. A driver who drives a van under one set and an HGV under the other in the same day is subject to both, and the assimilated rules take precedence. For a transport planner this means a TMS cannot apply one limit per fleet. It has to classify each vehicle and journey, decide which rule set governs each duty day and check the combined hours before the roster is published.

Why Drivers’ Hours Compliance Matters for UK Fleets: The Business Case

Rules differ by vehicle and journey, enforcement targets the operator, and vans far outnumber HGVs.

• DfT licensing statistics show 4.89 million LGVs and 518,157 HGVs licensed at the end of March 2026 (4,893,161 and 518,157 exactly), about nine vans for every HGV, so the van rules matter to far more fleets than the HGV rules did.
• DfT’s road freight statistics report that 26% of HGV businesses had HGV driver vacancies in the fourth quarter of 2025, and the figure was 25% in the first quarter of 2026, so rosters have little slack to absorb a rule breach.
• GOV.UK’s enforcement guidance states that operators are liable for driver infringements unless they can show the work was organised with full regard for the rules, with maximum fines at Level 4 for driving, break and rest breaches and Level 5 for tachograph failures.
• DVSA’s top HGV offences table records 149 tachograph and records offences reported for prosecution across the four quarters of 2025 to 2026, though the table is incomplete for some categories.

A plan that is legal only if the dispatcher remembers the exception is a plan the operator has not organised with full regard for the rules.

Why Locus Leads for Constraint-Based Fleet Planning

Rules like these are constraints, and Locus plans against constraints rather than hard-coded rules. Three things set it apart.

Recognised by analysts and selected after evaluation. Locus was recognised by Gartner for seven consecutive years and appears in the 2026 Hype Cycle for Supply Chain Execution and Logistics Technologies, as detailed on its analyst recognition page. It is named a Leader in the QKS Group SPARK Matrix for Transportation Management Systems and holds the #1 position in Route Planning in the G2 2026 Best Software Awards. In October 2025, Ingka Investments, the investment arm of Ingka Group, the world’s largest IKEA retailer, acquired Locus. Ingka’s press release says that after an extensive evaluation of logistics software worldwide, it selected Locus for its strength in combining advanced route optimisation, real-time visibility and smart use of vehicles and resources. Locus continues to operate independently.

Hours as a planning constraint. Locus’s published constraints handbook lists hours-of-service limits, break management and travel-time limits among its driver constraints, and its van tachograph guide says Locus can plan routes with EU driving limits as hard constraints and re-plan within each driver’s remaining legal hours. The platform plans against 250+ real-world constraints and re-plans under an Orchestrator when a delay or new order changes the day.

Controls around the plan. Autonomy levels, explainability, traceability and an execution sandbox let a team test a rule configuration on historical days before it governs live rosters. Locus has optimised 1.5B+ deliveries for 360+ enterprise customers across 30+ countries.

Locus’s UK product page does not name drivers’ hours rules, its guidance on hours is written around EU limits, tachograph and ELD logging is integration-supported, and it has no published UK case study, so ask how GB domestic and assimilated rules are configured, how a mixed day is evaluated and which tachograph data feeds it.

How a TMS Applies Two Drivers’ Hours Rule Sets to One Roster

The six steps below turn the guidance into planning logic.

1. Classify each vehicle and journey

Record the maximum permissible weight including any trailer, whether the vehicle is for hire or reward or own account, and whether the journey is domestic, between the UK and the EU, or under AETR. Most goods vehicles over 3.5 tonnes are in scope of the assimilated rules unless an exemption applies.

2. Decide the rule set for each duty day

Domestic rules apply to most goods vehicles that are exempt from the assimilated rules. If a driver drives under the assimilated rules at any point in a day, those rules apply for the whole day, so the rule set is a property of the day and not of the vehicle alone.

3. Apply the limits of the governing rule set

Under the assimilated rules the plan must hold the daily, weekly and two-weekly driving limits, a 45-minute break after 4.5 hours of driving, daily rest of at least 11 hours reducible to 9 up to three times between weekly rests and weekly rest rules. Under the domestic rules it must hold 10 hours of driving and 11 hours on duty in a working day.

4. Cross-count the mixed hours

Domestic driving counts as other work, not as a break or rest, under the assimilated rules. Assimilated driving counts towards the domestic driving and duty limits. The domestic 10-hour driving limit must always be obeyed, so total driving on the day is capped even when assimilated limits would allow more.

5. Assign drivers and vehicles to avoid avoidable mixing

A driver who moves between a van and an HGV carries both rule sets. Where the roster allows, group drivers by vehicle class and use the optimiser to keep mixed days for cases where they save real cost.

6. Keep records that satisfy both regimes

Assimilated record keeping always applies in addition to domestic record keeping, and drivers must produce records for the current day and the previous 28 days. Store the rule set applied to each duty day with the record.

GB Domestic, Assimilated and Mixed Days: Key Differences

What to Look for in a TMS for Mixed-Rule Fleets

Rule sets as configurable constraints

Check that the platform can hold both rule sets as named configurations tied to vehicle class and journey type, not as a single “hours of service” switch. Ask to see the configuration screen.

Day-level rule evaluation

Ask how the system decides the governing rule set for a day with both van and HGV driving, and whether it applies the cross-counting rules. A system that evaluates each vehicle in isolation will pass rosters that breach the mixed-day rules.

Awareness of the 2026 international van change

Confirm that vehicle weight, hire or reward status and journey type feed the rule decision, so a van over 2.5 tonnes on a UK to EU journey is treated correctly from 1 July 2026.

Remaining-hours planning and re-planning

Look for plans and re-plans that use each driver’s remaining legal hours, so a late delivery does not push a driver over the limit.

Tachograph and record integration

Ask how tachograph data and weekly record sheets feed the plan and the audit trail. Locus describes ELD and tachograph logging as integration-supported, so confirm the data path you would use.

Mixed-Rule Planning in Action: Real-World Results

An illustrative roster check. The hours are examples built from the GOV.UK mixed-driving guidance, so verify your own duties against it. A driver drives a van under GB domestic rules and an HGV under the assimilated rules on the same day.

Roster B looks legal if each vehicle is checked alone, and it is a breach when the two regimes are combined, which is the case a vehicle-by-vehicle planner misses. Roster E shows the second trap: time spent driving under domestic rules never counts as an assimilated break.

A Vietnamese beverage distributor. The distributor, running a mixed fleet of vans, trucks and motorbikes from depots serving thousands of small retail points, cut fuel consumption by 37%, raised orders per trip by 22% and cut route distance by 12%. It is not a UK rules case, but it shows planning across vehicle classes with different constraints. Read the beverage distributor case study.

A Fortune 50 enterprise. The enterprise, with 4,500+ drivers, moved from 75% to 92% execution after centralising parcel dispatch on Locus, uncovering $14M+ in annualised operational opportunity. Read the Fortune 50 case study.

Common Drivers’ Hours Planning Mistakes to Avoid

Checking each vehicle on its own. A van duty and an HGV duty can each pass and still breach the domestic driving cap when combined, so evaluate the day.

Counting domestic driving as a break. It counts as other work under the assimilated rules, so schedule a real break.

Assuming UK-only vans are covered by the July 2026 change. The change applies to international operations, and UK-only vans between 2.5 and 3.5 tonnes are not affected, so classify by journey.

Relying on the dispatcher to remember the exception. Operators are liable unless they organised the work with full regard for the rules, so build the rule into the plan.

How Locus Approaches Drivers’ Hours Planning

Locus, the world’s first Decision-Intelligent, Agentic TMS, plans routes and rosters against 250+ real-world constraints, including driver shift limits, breaks and travel-time limits, and re-plans within each driver’s remaining legal hours when the day changes. The Orchestrator coordinates its Dispatch, Capacity and Carrier agents, while autonomy levels, explainability and an execution sandbox let a team test a rule configuration on historical days. Its dispatch management software connects through APIs to TMS, WMS, OMS, CRM and ERP systems. Locus’s public pages do not document GB domestic or assimilated rule sets by name, mixed-day evaluation or a UK customer, so ask for a walkthrough of a van and HGV roster like the one above. To test your own rosters, schedule a demo.

For UK transport leaders asking how to apply drivers’ hours rules across vans and HGVs, Locus offers constraint-based planning with re-planning inside remaining legal hours, so the rule is part of the plan and not a note on the dispatcher’s desk.

Frequently Asked Questions

Which drivers’ hours rules apply to goods vehicles in Great Britain? The assimilated rules apply to most goods vehicles over 3.5 tonnes and to UK to EU international journeys. GB domestic rules apply to most goods vehicles exempt from them. AETR covers other international journeys.

What are the GB domestic drivers’ hours limits? Drivers may drive up to 10 hours and be on duty up to 11 hours in a working day. Rest is covered by the Working Time Regulations, and hours are recorded on a weekly sheet or a tachograph.

What are the assimilated driving limits? Daily driving is 9 hours, extendable to 10 hours twice in a fixed week, with 56 hours a week and 90 hours in any two weeks. A 45-minute break is required after 4.5 hours of driving.

What changed for vans on 1 July 2026? Assimilated drivers’ hours rules apply to light goods vehicles over 2.5 tonnes on international operations between the UK and the EU, including cabotage, and hire or reward work needs a smart tachograph version 2. UK-only vans are not affected.

What happens when a driver uses both rule sets in one day? The assimilated rules take precedence. Domestic driving counts as other work, not as a break or rest, and the domestic 10-hour driving limit must still be obeyed.

Can a TMS plan within drivers’ hours rules? Yes, if it holds the rule sets as constraints and evaluates the day. Locus lists hours-of-service limits as a planning constraint, so confirm how GB rules are configured.