Ask a room of drivers to state the daily rest rule and most will say “eleven hours” - correct as far as it goes, and incomplete in exactly the ways that generate infringements. The assimilated drivers’ hours rules build daily rest out of three interchangeable shapes - regular, reduced and split - each with its own conditions, plus a definition of “rest” itself that disqualifies half the things drivers assume count. The government’s goods-vehicle drivers’ hours guidance lays it all out, and it repays a careful read.
The baseline is the regular daily rest: a driver must take a daily rest period within each period of 24 hours after the end of the previous daily or weekly rest, and the regular form is at least 11 continuous hours. The first flexibility is the reduced daily rest: the requirement can be reduced to 9 continuous hours, but no more than three times between any two weekly rest periods - and, usefully, no compensation is required for the reduction. The guidance is explicit about the counting: a reduced rest is any daily rest of at least 9 but less than 11 hours, and the tally resets between weekly rests. That “three times between weekly rest periods” is the rule drivers most often misstate as “three times a week” - close, but the anchor points are the weekly rests, and on an irregular pattern the difference matters.
The second flexibility is the split daily rest: a regular rest taken in two separate periods - the first of at least 3 hours and the second of at least 9 hours. The order is fixed and the minimums are hard: a 4-hour afternoon stop plus an 8-hour overnight does not make a split rest, because the second period must reach 9. Drivers who understand the split rest use it to make delivery schedules work without burning a reduced-rest allowance; drivers who do not tend to discover the 9-hour minimum from an infringement report.
The cab question has a direct answer with conditions: daily rest periods may be taken in a vehicle, but the vehicle must have suitable sleeping facilities for each driver and it must be stationary - including during multi-manned journeys, because a driver taking rest in a moving vehicle is prevented from freely disposing of their time. “Freely disposing of their time” is the legal core of what rest is: an uninterrupted period where the driver may do as they please. A driver parked in a lay-by who must keep an ear on the load, or who is expected to move on request, is arguably not at rest at all - and the stationary-vehicle rule for multi-manning exists because the rules refuse to count sleep in a moving truck as rest, however good the bunk.
The guidance’s definition section carries the trap that produces the most disputed infringements: time spent working in other employment - regardless of occupation type - or in volunteering where there is an obligation to undertake duties cannot count as rest and must be counted as duty. The driver who finishes a trunking shift and works an evening job in a warehouse has not rested, whatever the tachograph mode says. The document handles the volunteer edge cases with care: driver CPC training can only be undertaken during rest periods if the driver attends voluntarily and not at the employer’s request, and retained firefighting, volunteer police work and similar commitments can only sit alongside driving if they do not eat into legally required rest.
For planners and transport managers, the three shapes are scheduling tools with compliance costs. A route plan that assumes an 11-hour rest every night is robust but wastes capacity; one that leans on reduced rests must count them, because the fourth 9-hour night between weekly rests is an infringement the analysis software will find. The split rest is the underused option - genuinely useful for early deliveries - but only when drivers know the 3-plus-9 structure and planners build to it. And every variation must survive the audit question the whole system asks: the tachograph record is the evidence, and a rest pattern that looked efficient on a whiteboard reads very differently in an examiner’s report when the data shows what actually happened.
The daily rest rules are the fatigue system’s daily bread - the mechanism that keeps driving time honest night after night. They are also, properly understood, more flexible than the “eleven hours” shorthand suggests - and the flexibility belongs to the operators and drivers who can state the rules exactly: 11 regular, 9 reduced three times between weekly rests, 3-plus-9 split, stationary vehicle, and rest that is genuinely rest.