Priority signs: deciding who goes and how to approach

General priority rules

When two vehicles are about to enter the same junction, traffic coming from the right generally has priority unless another instruction applies. Drivers must also give way to vehicles running on rails unless signs indicate otherwise. These rules apply when an authorised officer, traffic light or sign does not establish a different order.

Signs may change or confirm the general rule, but they never replace observation. A driver required to give way slows or stops so that others can pass without having to brake or change direction suddenly. A driver with priority still checks speed, visibility and possible mistakes by others: the order of passage does not cancel the duty to prevent a collision.

Rules for cycle spaces distinguish two situations. In pedestrian areas, urban cycle streets and cycle zones, permitted motor vehicles follow the general priority rules, and their drivers must take particular care around pedestrians and cyclists. On cycle lanes marked by a broken line, however, motor-vehicle drivers must give way to cyclists using the lane. To determine who goes first, identify the type of space and read its markings and signs.

Give way and STOP

The inverted triangle requires drivers to give way to traffic on the road they are about to enter. Its outline, unique among triangular road signs, remains recognisable even from behind. The driver reduces speed, examines both directions and stops only when stopping is needed to allow traffic with priority to pass without having to brake or change course, or to obtain an adequate view.

The red octagonal STOP sign creates a precise duty: bring the vehicle to a complete halt before entering the junction, at the stop line when one is provided, and then give way. The stop is compulsory even when nobody appears to be approaching. Check the traffic again before moving; stopping much too early, where there is no view, is not enough if you then advance without a second check.

• Give way: stop when necessary
• STOP: always stop, then reassess
• In both cases, leave the priority route unobstructed

Advance GIVE WAY and STOP signs

A triangular sign may warn in advance of a give-way or STOP sign by displaying its symbol together with the remaining distance on a supplementary panel. The warning is not the point at which the final stop must be made. It allows the driver to begin decelerating, locate the relevant road and reach the actual control with the vehicle already under command.

The stated distance is not the length of a hazard or priority road. On a fast approach, descent or road with restricted visibility, preparation may begin earlier. Confusing warning and prescription causes opposite mistakes: an unnecessary stop far from the junction, or passing the real sign without preparing for its requirement.

Junctions where priority is from the right

The triangle containing a black X announces a junction at which the general priority-to-the-right rule applies. Despite its triangular shape, it belongs to the priority-sign family and does not give priority to the road on which you are travelling. Reduce speed, identify every branch and look for vehicles, bicycles and other users approaching from the right.

The same priority-to-the-right rule applies at a junction that is not controlled differently. Priority cannot be inferred from road width, surfacing, heavier traffic or the apparent continuation of your own road. At a roundabout, the displayed signs decide the order: the circular shape alone is not enough to assume that traffic already on the roundabout always has priority.

Priority road and end of priority

A yellow diamond with a white border marks a road that has priority at subsequent junctions. It may be repeated and may carry a panel showing the course of the priority route. That diagram is especially important where the preferred road bends while a visually straight movement actually continues onto a secondary road.

The diamond crossed by a dark diagonal marks the end of priority-road status. By itself it requires neither STOP nor GIVE WAY, but it warns that the previous advantage cannot be assumed at later junctions: read the new signs or apply the general rule. Even before this sign, having priority does not justify blocking a congested junction or maintaining an unsuitable speed.

Side roads and merging traffic

Signs showing a heavy main stroke with one or more thinner branches warn of a junction with a secondary road. The drawing indicates whether the branch joins from the right, the left or both sides. Traffic on the main road has priority, yet its drivers should still anticipate vehicles that may emerge, turn across their path or misjudge the available gap.

A merge with an acceleration lane describes a gradual joining movement, common on divided high-speed roads. A driver on the acceleration lane matches speed, identifies a gap and gives way to traffic already on the main carriageway. Those already there need not change lanes, although they may facilitate entry when doing so is safe. The diagram distinguishes a merge from an ordinary crossroads.

Alternating traffic at a narrow section

Where a narrow section can carry only one direction at a time, two complementary signs set the order. The red-rimmed circular sign with opposing arrows, one red and one dark, requires the driver to give way to oncoming vehicles. Before entering, there must be enough room to clear the whole narrow section without forcing another user to reverse.

The blue rectangular sign with two opposing arrows indicates priority over oncoming traffic. It is still not an unconditional permission. If a vehicle has already entered, the far exit is blocked or the width will not permit passing, the driver waits. Shape and colour therefore separate a mandatory duty to yield from information that one's direction is preferred.

• Judge the full length of the restriction first
• Let vehicles already in the narrow section leave first
• Do not enter without clear space beyond the narrow part

Which instruction to follow at a junction

Approaching a junction, slow to match visibility and check, in order, officers, traffic lights, signs and road markings. An officer's direction overrides every other signal. When normal three-colour traffic lights operate, follow them; associated priority signs govern the junction again when the lights are off or flashing amber. Emergency vehicles using a siren and flashing beacon must still be given a clear path.

Turn indicators, eye contact and vehicle position provide useful information but are not a guarantee: an indicator may have been left on and another driver may have misunderstood the priority rule. Approach at a moderate speed and keep the ability to stop. If the situation is unclear, waiting a few seconds is safer than entering the junction because you expect others to respect your priority.