Frequently Asked Questions

• What is the difference between a Roundabout and Traffic Circle?
• Why not install traffic signals?
• Are roundabouts better for the environment?
• What prevents motorists from driving over the central island?
• Who has the "Right-of-Way"?
• How do I signal at a roundabout?
• Will landscaping be placed in the centre island?
• Will large trucks fit?
• What are the common types of collisions at Roundabouts?
• What do I do if an emergency vehicle comes through the roundabout?

What is the difference between a Roundabout and Traffic Circle?

A roundabout and a Traffic Circle are similar in that they are both circular, but they operate much differently.   At a roundabout, traffic entering must yield the right-of-way to traffic already in the roundabout.  Alternately in a traffic circle or rotary, vehicles in the circle yield to traffic entering the circle. 

Another key difference is size.  Traffic circles and rotaries are quite large (i.e. l’Arc de Triomphe in Paris).  By comparison, roundabouts are significantly smaller.  The reduced size of a roundabout restricts increases deflection reducing maximum vehicle speeds as drivers are required to adjust to the geometry.

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Why not install traffic signals?

Once accident and users costs are calculated, the installation of traffic signals would be much more costly over time than the construction of a roundabout.  The safety and environmental issues related to traffic signal intersections are also greatly improved with a roundabout.

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Are roundabouts better for the environment?

Vehicles approach the roundabout at a slow pace and yield to oncoming traffic rather than completely stopping and idling at a traffic signal controlled intersection.  Therefore, motorists have shorter delays which create less vehicle emissions.

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What prevents motorists from driving over the central island?

Standard roundabouts have a raised central island complete with barrier curb and landscaping.  

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Who has the "Right-of-Way"?

The vehicle in the roundabout has the right of way. The traffic from the connecting roads must yield for the traffic in the roundabout.

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How do I signal at a roundabout?

Lambton's installation is a single lane roundabout.  As such, signaling and lane positioning are relatively straightforward. Simply signal right.   For example:

When taking the first exit (turning right):  signal right, and keep to the right in the roundabout and continue signalling right to leave.

When taking the second exit (going straight through):  signal right after you have passed the exit before the one you want and exit directly from the lane in which you are travelling.

When taking the last exit (turning left) or going full circle (u-turn):  signal right after you have passed the exit before the one you want and exit directly from the lane in which you are travelling.

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Will landscaping be placed in the centre island?

Yes.  Landscaping is placed in the central island to restrict drivers from seeing across the roundabout.  Landscaping blocks the light from oncoming vehicles at night and provides drivers with a clear indication that there is an obstruction in the roadway.

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Will large trucks fit?

The roundabout is designed to handle large trucks.  A concrete apron is provided around the central island to accommodate the larger turning radius of these vehicles.

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What are the common types of collisions at Roundabouts?

There are two types of collisions that are more common at single lane roundabouts:

Rear end collisions:  This occurs when a vehicle hits the back of another vehicle, usually at the entrance to the roundabout.
Entering collisions:  This occurs when a vehicle entering the roundabout does not yield to a vehicle already in the roundabout.

These collision types are generally only minor "fender benders", as opposed to head on and turning collisions which are often more severe.

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What do I do if an emergency vehicle comes through the roundabout?

Do not stop inside the roundabout.  Stopping in the roundabout will block emergency responders.  If you have not yet entered the roundabout, pull to the right and let the emergency vehicle pass you.  If you are in the roundabout, exit as normal, then pull to the right, as soon as possible, and let the emergency vehicle pass you.

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