7.1 Prohibitory Regulatory Signs
Key Takeaways
- Prohibitory regulatory signs are mostly circular with a red border on a yellow or white background; they tell you what is FORBIDDEN
- The STOP sign is the exception: it is the only octagonal (8-sided) prohibitory sign and requires a complete stop before entering
- Classic Nigerian Highway Code examples include STOP at intersection, STOP Police, no left/right/U-turn, overtaking prohibited, no entry (all vehicles, lorries, cycles), no horn, maximum speed, derestriction, parking prohibited, no stopping, and height/width/weight limits
- Derestriction ends a previous restriction (often a speed limit); it is not permission to drive recklessly or ignore other rules
- Do not confuse red-border prohibitory circles with blue-background mandatory circles — red-border forbids; blue-background commands
Why prohibitory signs dominate FRSC CBT items
Regulatory signs are the law painted on a board. The Nigerian Highway Code (Part Two, Section B — Road Signs, Signals, and Markings) states that a thorough knowledge of traffic signs, signals, and pavement markings is compulsory for all drivers. Road signs, together with signals from authorised traffic officers, exist to keep traffic smooth and safe.
Within the regulatory family there are two CBT-critical branches:
- Prohibitory signs — what you must not do.
- Mandatory signs — what you must do (Section 7.2).
This section owns the forbid half. If you misread a red-border circle as a “suggestion,” you fail both the exam and the roadside.
Quick Answer: Prohibitory regulatory signs are mostly circular with a red border on a yellow or white face. They mean the action shown is FORBIDDEN. The STOP sign is the special case: it is the only eight-sided (octagonal) prohibitory sign and means come to a complete stop, then proceed only when safe. Never swap these red-border circles with blue-background mandatory circles (Section 7.2).
Nigeria drives on the right-hand side of the road. You will meet these signs at junctions in Lagos, Abuja, Port Harcourt, and on inter-state highways under FRSC and state traffic control. The CBT tests Code recognition, not “what drivers sometimes do when no marshal is watching.”
Shape and colour: the memory system that saves marks
The Highway Code teaches you to recognise shape and colour families even before you read a symbol:
| Family | Typical shape | Typical colour cue | Legal force |
|---|---|---|---|
| Prohibitory regulatory | Circle (red border) | Red ring on yellow/white; black symbol | Forbidden action |
| STOP (special prohibitory) | Octagon (8 sides) | Red face, white legend | Complete stop |
| Mandatory regulatory | Circle | Blue background, white symbol, no red border | Must do (Ch 7.2) |
| Warning | Triangle (point up) | Red perimeter | Hazard ahead (Ch 8) |
| Yield / Give way | Inverted triangle | Red perimeter | Give way (Ch 8) |
| Information | Rectangle | Various | Guidance (Ch 8) |
Code wording to own: regulatory signs are mostly circular. Those with red and yellow circles are prohibitive. Those with blue circles but no red border are mandatory and give positive instructions.
Exam trap: “circular = always stop”
Not every circle is a stop. A circular maximum speed limit forbids exceeding the number shown; a circular no left turn forbids that turn; a circular no entry forbids entry. Only STOP (octagon) and certain STOP Police / STOP Customs style plates force a full stop obligation of that character. Read the symbol and inscription, not only the outline.
STOP family: intersection, Police, Customs
STOP at intersection
The Highway Code is explicit: the stop sign is a prohibitive sign. It is the only 8-sided traffic sign. Meaning:
- Come to a complete stop before entering.
- Proceed only when it is safe to do so.
- Stop behind the stop line (or at a clear sight point if lines are faded) so you can see crossing traffic.
A “rolling stop” that never fully arrests the vehicle is not Code-compliant. On the CBT, if options contrast “slow down” versus “complete stop,” choose complete stop.
STOP Police
STOP Police appears where officers require vehicles to halt for checks, control, or enforcement. Treat it as a hard stop obligation at that control point — not optional courtesy. Inscriptions can vary for other stop duties.
STOP Customs
STOP Customs is listed in the Code with the note that the inscription may be varied to suit other obligations to stop. Mentally file it with the stop family: when you see a STOP plate with an authority inscription, you stop for that control.
Scenario A. Chinedu approaches a red octagonal STOP at a crossroads with light traffic. He eases through at walking pace without fully stopping. That is wrong under the Code definition of the stop sign.
Scenario B. Amaka sees STOP Police at a temporary checkpoint. She must stop as directed; “I am late for work” is not a Code defence.
Movement prohibitions: turns, U-turns, overtaking
These circular red-border signs ban specific manoeuvres even if the road geometry “looks possible.”
| Sign (Highway Code label) | What is forbidden |
|---|---|
| No left turn | Turning left at that location |
| No right turn | Turning right at that location |
| No “U” turn | Reversing direction with a U-turn there |
| Overtaking prohibited | Overtaking; often supplemented with road marking including “no change lane” |
Overtaking prohibited + markings
The Code notes that overtaking prohibited may be supplemented with road marking including “no change lane.” So a stem that pairs a no-overtaking sign with solid centre-line logic is testing two channels of the same rule: sign and marking. Chapter 8 deepens markings; for 7.1, remember: the sign alone already forbids overtaking in that stretch.
Scenario C. Bode wants to U-turn across a dual carriageway median opening marked No U-turn. He must continue to a legal turning facility. Choosing “U-turn only if no oncoming car is visible” is still wrong when the prohibitory sign is present.
Entry prohibitions and dimensional limits
The Highway Code prohibitory list includes several no-entry and size/weight controls that appear often in recognition items:
| Sign | Meaning (forbid) |
|---|---|
| No entry for all vehicles | No vehicle may enter |
| Close to all vehicles in both directions | Road closed to all vehicles both ways |
| No entry for lorries | Lorries must not enter |
| No entry to pedal cycles | Pedal cycles must not enter |
| No entry for vehicles having overall width exceeding 2 m | Width over 2 m forbidden |
| No entry for vehicles having overall height exceeding 3.5 m | Height over 3.5 m forbidden |
| No entry for vehicles having axle load exceeding 8 metric tonnes | Axle load over 8 t forbidden |
| No entry for vehicles exceeding 12 metric tonnes laden load | Laden mass over 12 t forbidden |
Why numbers matter on the CBT
Stems love to swap 2 m width, 3.5 m height, 8 t axle, and 12 t laden. Do not invent different figures. If your private car is under every limit, you may still face no entry for all vehicles or road closed both directions — class exceptions do not erase a total closure.
Scenario D. A box truck is 3.6 m high approaching a 3.5 m height limit. Entry is prohibited even if the driver “thinks the bridge looks tall enough.”
Behaviour and roadside use: horn, parking, stopping, litter, speed
No horn
No horn forbids sounding the horn in that zone (hospitals, schools, quiet zones, and other posted stretches). It is not a ban on all sound forever — it is a posted prohibition you must obey where signed.
Speed limit (maximum)
The circular maximum speed limit forbids exceeding the figure shown. It works with Chapter 6’s vehicle/road table: a posted lower maximum binds. Exceeding a posted maximum is a classic enforcement and CBT item.
Derestriction sign
The derestriction sign ends a previous restriction — most often the end of a signed maximum speed restriction. Critical CBT nuances:
- Derestriction is not “drive as fast as you like.”
- You return to the general Highway Code maxima for your vehicle and road type (Chapter 6), still adjusted for conditions.
- Other prohibitory and mandatory signs remain in force unless separately ended.
Parking prohibited and no stopping
| Sign | Practical forbid |
|---|---|
| Parking prohibited | You must not park there; the Code example shows time-banded parking prohibition (e.g. 8.30 a.m. to 5.30 p.m.) — when a plate shows hours, those hours control |
| No stopping | Stronger than no parking: you must not stop (except as required by traffic control, emergencies, or officer direction) |
Parking prohibited ≠ no stopping. No stopping is the stricter control. If a stem asks which is stricter for a brief halt to drop a passenger where both signs are options, no stopping is the tighter forbid.
Litter prohibited
Litter prohibited forbids dumping refuse from the vehicle or onto the roadside at that control. Clean-road rules support safety (debris) as well as amenity — treat it as a real prohibitory item, not a joke option.
CBT trap map: red-border vs blue circle
This is the highest-value trap linking 7.1 to 7.2:
| You see | Background / border | Correct mental label | Wrong instinct |
|---|---|---|---|
| Circle, red border, yellow/white face | Prohibitory | Must not do the symbol | “Blue means forbid” |
| Circle, solid blue, white symbol | Mandatory | Must do the symbol | “Looks like info only” |
| Red octagon STOP | Prohibitory special | Complete stop | “Slow is enough” |
| Triangle red border | Warning (Ch 8) | Hazard ahead, not a ban by itself | Treat as no-entry |
Drill sentence: Red ring forbids. Blue disc commands. Octagon stops.
Link forward
Section 7.2 lists the blue mandatory set (direction to be followed, roundabout, keep right, minimum speed, and more). Section 7.3 covers traffic lights and officer signals that can override or reinforce fixed signs when an authorised person is directing traffic. For pure sign recognition on the CBT, master the forbid list and the shape/colour keys in this section first.
According to the Nigerian Highway Code description of regulatory signs, which statement best describes prohibitory signs?
What makes the STOP sign special among prohibitory signs in the Nigerian Highway Code?
Extra practice: dimensional and closure stems
When a stem quotes a number, match it to the Code label exactly:
- Width limit example: 2 m overall width.
- Height limit example: 3.5 m overall height.
- Axle load example: 8 metric tonnes.
- Laden load example: 12 metric tonnes.
If the stem says close to all vehicles in both directions or no entry for all vehicles, private-car status does not create an exception. If it says no entry for lorries, a private car may still enter unless another sign forbids all vehicles — read the specific class named on the plate.
Parking time bands
Where parking prohibited is shown with hours (Code example 8.30 a.m. to 5.30 p.m.), the prohibition applies during those hours as posted. Outside posted hours, other general parking and stopping rules, markings, and local controls still apply — derestriction of one plate does not invent free parking on a carriageway or bus bay.
Study drill: say the forbid ladder aloud
- Red ring = forbidden.
- Octagon STOP = complete stop.
- No left / right / U-turn = no that manoeuvre.
- Overtaking prohibited = no overtaking (watch markings too).
- No entry / closed both ways = do not enter.
- Max speed circle = do not exceed.
- Derestriction = end of that restriction, not unlimited speed.
- No parking vs no stopping = stopping ban is stricter.
If those eight lines are automatic, most 7.1 recognition items become routine.
A circular regulatory sign shows a maximum speed of 40. What does it mean under prohibitory logic?
Which pair correctly matches a Highway Code prohibitory idea with its meaning?
A learner confuses a red-border circular ‘no left turn’ with a blue circular ‘direction to be followed’ sign. What is the correct distinction for the FRSC CBT?