Mandatory signs are blue circles with a white symbol, and they tell you what you must do. There are 10 on the chart. Where a warning sign says "be ready" and a prohibitory sign says "don't", a mandatory sign says "do this". If you see a blue disc, it's an order, not a suggestion.
They are the smallest of the main classes, which makes them a quick win. They're also the class most often confused with the prohibitory signs, because the same arrows and pictures appear on both, with opposite meanings.
Blue means you must
The Ministry of Roads road signs manual splits regulatory signs into two kinds. Mandatory signs give instructions that must be obeyed, and most are circular with a white symbol and border on a blue background. Prohibitory signs tell you what you must not do, and most are circular with a red border.
That gives you a simple rule for any round sign:
- Blue background, white picture: do what the picture shows.
- White background, red ring: don't do what the picture shows, or keep to the limit on it.
The manual also counts Stop and Give way as mandatory, since they're instructions you must follow. On the chart and in the trainers they have their own class, priority signs, because their shapes are unique.
The three groups
Which way to go. Vehicles travel straight, vehicles turn right, the direction to be followed, the straight-or-right sign and pass to the left. Each shows a white arrow, and the arrow is the whole message: the number of arrowheads tells you how many choices you have.
Who the lane is for. Compulsory cycle track, the compulsory footpath for pedestrians, and the compulsory track for cattle. The picture tells you who the path belongs to. Everyone else stays off it.
How slow you may go. Compulsory minimum speed and its end sign. These are the only mandatory signs with a number on them.
Arrows: count the heads, read the angle
The arrow signs are where most points are lost.
- One straight arrow up means straight on is your only choice. Both turns are ruled out.
- One arrow that bends means you must turn that way. A bend in the arrow means a turn at a junction.
- An arrow that splits gives you a choice between the directions it shows, and nothing else.
- An arrow slanting down to the left isn't about turning at all. It tells you which side to pass something, like a traffic island in front of you. Keep left of it.
Before you signal, count the arrowheads. One head means one way out.
Blue against red: same picture, opposite meaning
The easiest way to lose a mark is to read the picture and skip the colour.
- A white arrow turning right on blue orders you to turn right. A black right-turn arrow under a red bar, inside a red ring, is no right turn. Same arrow, opposite meaning.
- A bicycle on blue sets a track aside for bicycles. A bicycle in a red ring with a slash bans them.
- A number on blue is a minimum speed: you must go at least that fast. A number in a red ring is a speed limit: you may not go faster. Treat the blue number as a floor and the red one as a ceiling.
Minimum speed, and where it ends
The minimum speed sign keeps very slow vehicles off roads where they would hold up fast traffic and become a danger. It never means you should drive faster than is safe: if traffic, weather or visibility make the number unsafe, conditions come first.
The manual shows the sign that ends a minimum speed: the same blue disc, crossed through with red. After it you may go slower again, but any maximum speed limit still applies. Don't confuse it with the end of speed limit sign, which is white with black lines and ends a maximum.
Tracks for cyclists, people and cattle
The manual describes the cycle track sign as marking the start of a track reserved for pedal cycles, used together with cycle-track road markings, and says motor vehicles are not allowed on it. The footpath and cattle track signs follow the same idea: the path is for whoever is drawn on the sign.
For a driver, the lesson is to keep off, and to watch where these paths cross your road at junctions and driveways, because whoever uses them may come across your path.
How to learn them
With only 10 signs, mandatory signs make a good first round on the Pelican chart trainer. Then drill them mixed in with the prohibitory signs, since telling blue from red with the same picture is what the test is really checking. The 3D trainer helps you read the arrows from an angle, as you would at a real junction.
All 10 mandatory signs
- Direction to be followedYou must go the way the arrow points. No other direction is allowed here.
- Vehicles travel straightAll vehicles must go straight on. You may not turn left or right here.
- Vehicles turn right junctionAll vehicles must turn right at this junction. Going straight on or turning left is not allowed.
- Vehicles travel straight or rightYou may only go straight on or turn right at this junction. Turning left is not allowed.
- Pass to the leftGo past the obstacle or island on your left side. Never go to the right of this sign or island.
- Compulsory cycle trackThis track is for bicycles. Motor vehicles may not use it.
- Compulsory pedestrian foot pathPedestrians must walk on this path. Cyclists and motor vehicles must stay off it.
- Compulsory track for cattleLivestock must keep to this track. Drivers should slow down, since animals may be around.
- Compulsory minimum speedYou must drive at the speed shown or faster. Going slower is not allowed. You'll mostly see this on highways and expressways.
- End of compulsory minimum speedThe minimum speed ends here. Normal speed limits apply from now on.
Sources
- Design Manual for Roads and Bridges, Part 5a: Road Signs, Ministry of Roads, draft of December 2009. Chapter 5 covers regulatory signs, including the minimum speed and cycle track signs.
- The sign artwork and codes are from the chart used in the DriveRush trainers.