【Road Trivia】What is the difference between traditional roundabouts and new spirals? !
1. Definition and design basis
1. Conventional Roundabout
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Design features:
- There is a circular island in the center with multiple entrances and exits around it.
- Entering vehicles must "yield to the right" (i.e. let vehicles in the inner circle go first).
- There are no obvious lane separations at the entrance and exit, and the inner and outer circles can be switched freely.
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Road signs:
- There is often a "circular arrow" sign in the center, and the road surface is single-lane or multi-lane.
2. New Spiral Roundabout
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Design features:
- There are preset lanes when entering the roundabout, and the turning route is "spiral" according to the exit direction.
- The interior of the roundabout is marked out with "guide lines" or "solid lines" to indicate lanes in different directions.
- You cannot cross lanes at will and must drive along the preset route.
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Road signs:
- Lane arrows, exit numbers and intersection names are clearly marked on the ground.
- There are "lane separation signs" and "spiral guide map" before entering.
2. Design and operation
| project | Traditional roundabout | New spiral roundabout |
|---|---|---|
| Lane separation | Inner and outer rings can be switched freely | The inner lanes are strictly separated by guide lines/solid lines |
| Entry method | After entering, you can choose the exit by cutting off the line | You must select the correct lane in advance and cannot change lanes at will after entering |
| Road markings | Relatively simple, mainly relying on the driver's judgment | Ground arrows, lane numbers and exit names are clearly marked |
| Traffic efficiency | High flow rate, easy to mess up, high risk of cutting | Standardize driving routes, reduce tangents and improve efficiency |
| Applicable scenarios | Intersections with low traffic volume and few exits | Complex intersections with heavy traffic, multiple exits, and multiple lanes |
3. Driving teaching and application
1. Key points for driving on traditional roundabouts
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Entry Rules:
- When entering the roundabout, give way to vehicles already in the roundabout.
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Lane Selection:
- Take the first exit (i.e. turn left): usually follow the leftmost lane.
- Take the second or subsequent exit (go straight, turn right or make a U-turn): You can choose the outer lane or inner lane.
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Tangent principle:
- After entering, you can gradually move to the outside according to the exit and prepare to leave.
- When leaving, you must turn on your turn signal and pay attention to vehicles in the inner and outer lanes.
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Common mistakes:
- Failure to use turn signals, forced lane cutting, and failure to give way to vehicles in the outside lane when leaving.
