A manufacturer walkthrough of barriers, cones, signs, kerb ramps and trench covers is not the most obvious revision material. But strip out the sales talk and what is left is a neat tour of the physical side of the O1 certificate: the kit you put on the ground, and the rules that decide whether it is compliant or not.
Two documents, one set of rules
Every product in the video is described as “Chapter 8 and Red Book compliant”. That phrase gets used loosely on site, so it is worth being precise about what each document is.
| Document | What it is | Who uses it |
|---|---|---|
| Chapter 8, Traffic Signs Manual | Department for Transport guidance on temporary traffic management, in two parts covering design and operations | Traffic management designers, mostly on higher-speed roads |
| Safety at Street Works and Road Works (the Red Book) | Code of practice issued under sections 65 and 124 of NRSWA | Everyone on a street works site |
The Red Book is the one you are tested on. It is written for operatives and supervisors, it is statutory in the sense that failing to follow it is evidence of failing your NRSWA duties, and its layouts and dimensions are what the O1 and S1 theory tests draw from. Chapter 8 sits behind it as the fuller reference, and you will meet it on dual carriageways and anywhere a bespoke traffic management scheme has been designed.
If you have read Open Book Does Not Mean Easy, you will know why this matters. The O1 test is open book. Knowing which book to open, and which section, is half the battle.
What the kit is actually for
The video groups its products by type. That grouping happens to follow the Red Book quite closely, so it is a useful frame for revision.
Barriers around excavations. Every excavation must be fenced on all sides. The Red Book asks for barriers that are continuous, stable and clearly visible, with a tapping rail near the ground so visually impaired pedestrians can detect them and a handrail at a suitable height. The video makes the point that deep excavations on live sites need something heavier and taller, and that is fair. The principle is that the barrier must physically stop someone falling in, not just mark the edge.
Chamber and manhole guarding. An open chamber is an excavation for guarding purposes even if nobody has dug anything. The modular gate systems shown in the video exist because a lone operative opening a cover in a footway still needs a complete, stable barrier around it. Anyone who has done the LA certificate will recognise this from the other direction: the chamber you are guarding is somebody else’s apparatus.
Cones. The video says cone size “varies depending on the required application”. The Red Book is more specific: minimum cone height depends on the speed limit of the road. Low-speed streets take a smaller cone, higher-speed roads need the taller one. Choosing the wrong size because that is what was on the van is a classic inspection failure.
Signs and ballast. This is where the video earns its keep.
No more non-compliance fines for fallen-over signage.
A sign lying on its face is worse than no sign at all, because it becomes a trip hazard while telling drivers nothing. The Red Book requires every portable sign to be weighted down, and it is specific about how: sandbags or purpose-made ballast, never kerbstones, bricks or other hard objects. Hard ballast becomes a missile if the sign is struck and a hazard if the sign falls.
Kerb ramps. If pedestrians are diverted off the footway and onto the carriageway, or over a kerb into a temporary walkway, they need a ramp. The Red Book asks for a firm, non-slip surface with no trip hazard and a gradient a wheelchair user can manage. The video’s emphasis on ramps that do not slide is the right emphasis. A ramp that moves under a wheelchair is not an access measure, it is a hazard you built yourself.
Footway boards and trench covers. Temporary covers over open trenches must be strong enough for whatever will cross them, fixed so they cannot shift, and flush enough that there is no lip to catch a foot. The video talks about covers rated for vehicles up to a stated weight. The transferable rule is simpler: know the load the cover will take, and never assume a footway board is fit for a carriageway.
The pattern underneath all of it
Look at the list again and the same three requirements keep recurring.
- Visibility. Retroreflective materials to the relevant British Standard, high-visibility colours, lighting where the Red Book requires it. If a pedestrian or driver cannot see it, it is not doing its job.
- Stability. Ballasted against wind, footed against tripping, fixed so nothing moves under load. Almost every failure on an inspection is a stability failure: a fallen sign, a barrier blown over, a board that has slid.
- Completeness. Barriers all the way round, a continuous pedestrian route from one end of the site to the other, no gaps where the kit ran out.
Those three ideas are what the O1 theory test is really probing when it asks about barriers, cone heights or ballast. It is not asking you to recall a catalogue. It is asking whether you know what compliant looks like and can find the clause that proves it.
Where the supervisor comes in
The S1 certificate covers exactly the same ground from the other side. The operative erects the kit; the supervisor checks it against the Red Book, records what they find and gets it corrected. The S1 test therefore leans harder on the “what is wrong with this layout” style of question, and on knowing when a site should be closed or made safe rather than left running.
Both O1 and S1 are key certificates. As set out in Which Street Works Certificates Do You Actually Need?, if your O1 lapses, every other operative unit you hold stops being valid with it. The same is true of S1 for the supervisor units. That makes signing, lighting and guarding the one topic no one on a street works site can afford to be rusty on.
A quick site check before you sit the test
Next time you walk onto a live site, run this list against what you see. It is the same list the examiner is thinking about.
| Item | Red Book question to ask yourself |
|---|---|
| Cones | Are they the right height for the speed limit? Is the taper the right length? |
| Signs | Weighted with sandbags or proper ballast? Right size for the road? Facing the traffic? |
| Barriers | Continuous around the whole excavation? Tapping rail and handrail where pedestrians pass? |
| Pedestrian route | Is there a clear path of adequate width? Ramps where the kerb is crossed? |
| Covers and boards | Rated for the load? Fixed? Flush with no trip lip? |
| Lighting | Lamps where the Red Book requires them, and working? |
If you can answer every one of those from memory and then find the clause in the Red Book to back it up, you are ready for O1.
How NRSWA Revision Fits In
NRSWA Revision: Street Works is an independent revision app for iPhone, iPad and Android. It holds 1,110 practice questions across 14 street works certificates, and every answer is explained and sourced to the Red Book, SROH or HSG47, so when a question asks about cone heights or ballast you can see exactly where the rule comes from.
The O1 pool has 140 questions on signing, lighting and guarding, and the S1 pool has 80 on monitoring it. Each certificate also has a 20-question timed mock test that matches the real theory test format of 20 questions, 45 minutes and 16 to pass. If you want to try the format before you buy, 192 questions are free on the website, and the mock test will tell you quickly whether you can find the right page under the clock.
It is revision material, not a qualification. The card still comes from passing the assessed units. But knowing what compliant kit looks like, and being able to prove it from the book in under two minutes a question, is what gets you through the test on the first attempt.
