Safety inspection intervals for buses and coaches. Keep them, or show why they changed.

When you applied for your operator licence you told the Traffic Commissioner how often each vehicle would get a safety inspection. That figure is recorded against your licence on the vehicle operator licensing system, VOL, and it is a promise. Keep to it and nobody asks questions. Let it drift and it is one of the first things a DVSA examiner will find.

DVSA’s Guide to maintaining roadworthiness is the reference for how intervals should be set and managed. It distinguishes between what you must do, which is a legal requirement or an undertaking on your licence, and what you should do, which is best practice that you are expected to follow unless you can show an alternative works as well. Traffic Commissioners treat the guide as the starting point for deciding whether your arrangements are good enough.

What a safety inspection is

A safety inspection is a periodic check at a set interval, separate from routine servicing. It must cover at least everything tested at the annual test, using the methods in the relevant inspection manual, and every inspection is expected to include an assessment of brake performance, covered in our guide to brake testing at safety inspections. For buses and coaches that means the PSV inspection manual. A service is something else: oil, filters and the jobs the manufacturer lists. You can do both on the same visit, but the inspection has to stand on its own.

Two other checks sit around it. A first use inspection is needed before a newly acquired vehicle goes on the road, unless there is good evidence it has just had one, such as a pre-delivery inspection or a hire company’s pre-rental record. An intermediate safety check looks at specific high-wear items between full inspections. The guide gives urban buses as an example of vehicles that may need brakes, steering and suspension checked more often. Intermediate checks must be recorded and clearly labelled as such, not passed off as full inspections.

How to set the interval

The guide says operational needs must not override safety, and that inspections should follow a time-based pattern where practical. The interval should reflect how quickly the vehicle is likely to deteriorate, judged on:

• the age and type of vehicle
• the manufacturer’s recommendations
• what it carries and the equipment fitted to it
• the type of work it does
• the terrain and conditions it operates in
• the distances and speeds it covers, and how long it is out on the road

The guide gives a table of example frequencies. Most rows are worded around haulage, but the age row applies to buses and coaches too. Intervals would normally fall between 4 and 13 weeks.

The last row matters to a lot of coach operators. The guide sets a minimum frequency of 6 weeks for vehicles aged 12 years and older, because older vehicles fail more MOTs and pick up more defects in service. It allows that frequency to be extended for low mileage and light use, but you would need to be able to show why.

The guide’s case studies include two bus operators. One inspected its older, less reliable buses every 4 weeks and newer ones every 6. Another moved its buses under six years old from 28 to 42 days, kept the older ones where they were, and monitored for a year to confirm nothing got worse. Both had to update VOL. When the fleet runs mixed frequencies, VOL records the maximum and the mixed frequency box is ticked.

New operators and experienced ones

A new operator has no history to go on, so the advice is to be cautious and inspect more often rather than less, then watch the results closely. An experienced operator has more freedom to tailor the schedule, including by mileage, but a mileage-based schedule still has to be linked to time, and VOL records the time-based maximum equivalent, up to 13 weeks. If you change your schedule, the guide suggests monitoring the effect monthly and going back if defects rise.

Keeping to it: ISO weeks

The guide recommends planning in ISO weeks, which run Monday to Sunday. An inspection is on time if it is done within the ISO week it falls due. On a 6 week interval starting in week 10, the next inspections fall in weeks 16, 22, 28 and so on.

What you cannot do is borrow time. If a vehicle is inspected early in week 20, you cannot then leave it until week 28. Either inspect again in week 22 and stay on the original pattern, or restart the 6 week cycle from week 20, giving weeks 26, 32 and onwards. The guide also says the interval should not be extended without updating VOL first.

The examiner’s maintenance investigation questions are clear about how this is judged. Under question 4c, an occasional slip into the next ISO week is mostly satisfactory. A system that is obviously not managed, or defects on inspection sheets that show the interval is too long, is unsatisfactory. Small extensions to inspection frequency are also named in the Senior Traffic Commissioner’s guidance on decision making, as the kind of single-issue failing that might be dealt with by a meeting rather than a full hearing. Persistent ones are another matter. Our guide to DVSA maintenance investigations covers the rest of the question set.

Forward planning

Inspections should be planned at least six months ahead. A wall chart or year planner is acceptable. A digital system is equally fine and can schedule the next inspection automatically from the last one. Either way the planner should include every vehicle, its MOT date, and other dates such as tachograph calibration and checks on lifting equipment, such as passenger lifts. Planning around the MOT avoids doing the same preparation work twice.

Question 4d of the maintenance investigation asks whether an effective forward planning system is in use. A planner that exists but is used inconsistently is mostly satisfactory. No planner, or one that does not work, is unsatisfactory.

VOR and the missed inspection

Vehicles off the road are where intervals most often go wrong. The rules in the guide are straightforward:

• When a vehicle is declared VOR you must record it on the vehicle’s maintenance file, with the date and reason.
• You can suspend the inspection schedule if the VOR period runs over the next planned inspection. This is common for seasonal vehicles and long repairs.
• A VOR vehicle that has missed its planned inspection can only go back into service after an inspection confirms it is roadworthy. Future inspections can then be scheduled from that date.
• You may move a VOR vehicle before it returns to service, for example to the workshop, an MOT or a road test after repair.
• You must have a system that stops VOR vehicles being used.

Examiners check VOR records against tachograph data, telematics or duty schedules. A coach marked off the road that shows up on a school run is a problem. Using a VOR vehicle that has a safety-critical defect, or recording a false VOR to hide use, is a report to the Traffic Commissioner.

When an inspection is missed

It happens: a breakdown, a vehicle stuck on a hire, a workshop short of staff. What matters is what you do next.

1. Take the vehicle off the road, or keep it off, until it has been inspected. The guide only allows the schedule to be suspended for a vehicle that is VOR, so a vehicle in service has no slack past its due week.
2. Get it inspected as soon as possible and record the inspection in full, including the brake performance assessment.
3. Decide whether to return to the original schedule or restart the interval from the new date. Do not stretch the gap to catch up.
4. Write down why it was missed and what you have changed, such as a reminder further ahead or a backup slot with another workshop.
5. If it keeps happening, look again at the interval or your workshop capacity. Repeated slippage suggests the plan does not fit the operation.

If the vehicle was used beyond its due date without inspection, record that honestly too. An examiner analysing your records will see the gap anyway, and an explanation with corrective action reads very differently from a gap with nothing beside it.

Checking the interval is right

The guide is clear that the inspection results should be used to test the interval. If inspections keep finding lots of faults, the vehicles may need inspecting more often, drivers may not be checking properly, or defects are not being fixed. If inspections hardly ever find anything, the interval may be too short, or the inspections may not be thorough enough. Both are worth looking into. The guide also suggests having a competent third party re-inspect vehicles from time to time.

A practical checklist

• Check the inspection frequency on VOL matches what you actually do, including the mixed frequency box if intervals vary.
• Plan every vehicle’s inspections, MOT, tachograph calibration and passenger lift dates at least six months ahead.
• Work in ISO weeks and treat the due week as a deadline, not a target.
• Give vehicles 12 years old or more a 6 week interval unless you can justify longer.
• Record every VOR with a date and reason, and inspect before return if a planned inspection was missed.
• Do a first use inspection on every hired, borrowed or newly bought vehicle unless you hold evidence of a recent one.
• Keep every inspection record for at least 15 months, as set out in our page on maintenance records.
• Review defect rates per vehicle at least quarterly and adjust intervals where the evidence says so.

PSVault holds an inspection interval per vehicle in its forward planner and fleet board, and before a safety inspection sheet can be signed it flags an inspection that is late with no VOR record covering the gap.