Why junctions deserve extra attention
Junctions are where paths cross, so they are where conflicts between vehicles, cyclists and pedestrians are most likely. Roundabouts and large or unusual junctions can feel confusing because there is more to watch and the correct action is less obvious. Fortunately, a few principles apply to almost all of them.
Rules differ widely between countries and even between regions. These include which direction traffic circulates, who has priority, how lanes are marked, and how signaling is expected to work. This article describes general principles only. Before driving in a new area, consult your local driver’s handbook or licensing authority.
What a roundabout is trying to do
A roundabout lets traffic from several directions flow through a junction without stopping at a signal, by having vehicles circulate in one direction around a central island and yield on entry. Compared with a traditional crossing junction, vehicles travel at lower speeds and conflict points are fewer, with reduced severity in many designs. That is the design intent, though outcomes depend on how well drivers use them.
Typical features include:
- A yield or give-way line at each entry.
- Signs and road markings showing lanes and destinations.
- Splitter islands, which are raised or painted areas that separate entering and exiting traffic and slow vehicles.
- Crosswalks for pedestrians, usually set back from the circle.
General principles for roundabouts
1. Approach slowly and look ahead
Slow down early, using the same anticipation described in smooth driving. Read signs and markings as you approach, since they typically show which lane leads to which exit. Look at the shape of the junction, and note the number of exits and any lane markings.
2. Choose your lane early
Select your lane before the entry rather than changing at the last second. As a general guide, use the signs and markings. Many places direct drivers turning right (in right-hand-traffic regions) or taking later exits into the lane that leads around the outside or the inside, depending on local convention. If you are unsure, follow the arrows painted on the road. See lane changes for tips on adjusting lanes calmly before the junction.
3. Yield as required
In most places, you must give way to traffic already in the circle, and often to pedestrians at the crossing. Look in the direction that circulating traffic approaches from. Do not enter until there is a gap large enough for you to join without making others brake sharply. Some roundabouts have signals, and you must follow them.
4. Enter and circulate steadily
Once you have a suitable gap, accelerate gently and join the flow. Keep to your lane within the circle, since drifting across lines creates conflict. Avoid stopping inside the roundabout unless traffic ahead forces you to.
5. Signal sensibly
Signaling practices differ by region. In many places, drivers signal their intended exit shortly before leaving, so that those waiting to enter know what is happening. Signaling too early can mislead others. Where in doubt, follow your local handbook.
6. Check mirrors and blind spots before exiting
Before leaving the circle, check for vehicles alongside, especially in multi-lane roundabouts, since they may be traveling in the same direction in the adjacent lane. This is a case where understanding blind spots makes a practical difference. Also watch for cyclists, who may be on the inside of your path.
7. Be careful with large vehicles
Trucks, buses and vehicles towing trailers may need to use more than one lane to get around. Give them room, and avoid moving alongside them in the circle.
Multi-lane and spiral designs
Larger roundabouts with several lanes can be more demanding. The key points are to read the markings, choose a lane early, maintain your lane throughout, and avoid sudden moves. If you inadvertently miss your exit, it is generally safer to continue around the circle again than to cut across lanes.
Other complex junctions
Not every confusing junction is a roundabout. The following tips apply to many types.
Large signaled intersections. Look for turn lanes and separate signals for each. Check which lanes allow turning and which allow straight travel, and stay in the lane you chose. When turning across oncoming traffic, wait for a safe gap and for pedestrians to clear the crossing. Do not enter if you cannot clear the junction, as blocking cross traffic causes gridlock.
Five-way or irregular junctions. Slow down and treat each approach carefully. Identify who has the priority by signs, markings or signals. If you cannot work it out, proceed cautiously and be prepared to yield.
Multi-lane turns. Where two lanes turn together, stay in your lane through the turn. Keep an eye on vehicles beside you, which may drift.
Junctions with trams, bike lanes or bus lanes. Watch for unusual rules about when you may cross or share lanes. Cyclists often travel straight through where you may be turning, so check mirrors and the blind spot before crossing a bike lane.
Highway interchanges. Plan your route ahead using GPS navigation or signs, and position yourself early. The ramps merge and diverge quickly, which relates to the merging techniques described for highways.
Uncontrolled junctions. Where there are no signs or signals, local rules about priority (such as yielding to the right or to the vehicle that arrived first) apply. Learn them, and if another driver hesitates, be ready to wait for a clear signal that you can go.
Common mistakes
- Entering too fast and having to brake hard.
- Choosing the wrong lane and then changing lanes in the circle.
- Failing to yield to circulating traffic or pedestrians.
- Stopping unnecessarily inside the roundabout.
- Misleading signals, such as indicating left when continuing around.
- Ignoring cyclists and motorcyclists, who can be harder to see.
Practicing and planning
If a roundabout or junction worries you, study it on a map before you go, or practice on a quiet one with little traffic. Take a lesson with a qualified instructor if you are new to roundabouts. If the road is unfamiliar, stay patient. Taking an extra lap is better than a risky maneuver, and a short delay is better than a collision. Staying calm and seeing the junction as a series of small decisions, as encouraged in defensive driving, makes even complicated layouts manageable.