Roundabouts

What is a roundabout?

A modern roundabout is an unsignalized circular intersection with the following key design characteristics:

  • Yield on entry; priority to circulating vehicles
  • Pedestrian access & crossing
  • Lack of parking
  • Truck apron
  • Landscaped central island
  • Deflection of vehicle paths to reduce speed
Roundabout schematic drawing

What are the benefits?

Roundabouts are being used to improve safety, increase intersection capacity and efficiency, reduce environmental impacts, and enhance community values. Additional benefits may include lower costs over other types of intersections and greater design flexibility.

How are they being used in Lincoln?

The first modern roundabout at an intersection of two major arterial streets in Nebraska was built at 33rd and Sheridan in 2002. The intersection had been traffic signal controlled since 1980 and had a high rate of crashes using "traditional" traffic control measures. In the three years following completion of construction, total crashes dropped by 83%, with a 95% reduction in injury crashes. Not only were fewer people hurt, but the cost of property damage due to crashes was reduced by $810,000.

Since the initial success of the 33rd and Sheridan improvement, dozens of roundabouts have been installed throughout Lincoln, and more are planned in future projects.

33rd and Sheridan roundabout 33rd and Sheridan roundabout

Frequently Asked Questions

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Can a large truck go through a roundabout?

Roundabouts are designed to accommodate large trucks, however large trucks do need more space when driving in a roundabout. A "truck apron" on the edge of the center island in a roundabout, usually defined by colored concrete, allows large trucks and trucks with trailers to maneuver through a roundabout by allowing the wheels of the truck or trailer to roll onto the truck apron. All drivers should avoid driving next to or passing large trucks when maneuvering through a roundabout so the truck can safely make it through the intersection.

How should drivers yield to emergency vehicles?

If you have not entered the roundabout, pull over to the right and allow the emergency vehicle to pass. If you have already entered the roundabout, continue to the closest exit and pull over once beyond the splitter island to allow the emergency vehicle to pass. Never stop in a roundabout.

Why doesn't the City allow the public to vote on how or what type of intersection to have?

Decisions are based on engineering data, safety, cost, and public input. The City has received both positive and negative input for the existing roundabouts. Public opinion studies frequently show that support for roundabouts increases after construction when drivers become familiar with them.

Aren't these just being used until the City has the money for a traffic signal?

They are not short-term fixes or interim measures to a signal. In many instances they operate better than signals and many jurisdictions are removing signals and installing roundabouts.

Is a modern roundabout like a four-way stop?

Four-way stops require all traffic to stop prior to entering the intersection, while roundabouts only require motorists to YIELD at entry ways. Where a 4-way stop slows traffic and reduces the chance for right angle crashes, a roundabout provides the same benefit while keeping traffic moving much more smoothly.

How should bicyclists use roundabouts?

Bicyclists using the street in the roundabout should take their lane and ride with caution. Since speeds are slow within the roundabout, bicycles can often keep up with traffic fairly well. Less experienced bicyclists approaching a roundabout can exit the street at the pedestrian crossing, dismount and use the pedestrian crossings as a way to travel around the roundabout.

Are roundabouts safe for pedestrians?

In many instances, a modern roundabout can be safer for pedestrians than a traffic signal. This is due to the fact that a pedestrian crossing is reduced to two simple crossings of one way traffic proceeding at relatively slow speeds.

Pedestrian safety is enhanced by the presence of a Pedestrian Crosswalk sign placed right before a vehicle enters a modern roundabout. Even with this precaution, it is recommended that pedestrians use caution and always use the designated crosswalk.

Auto-pedestrian crash rates are usually lower at modern roundabouts than traffic signals Also pedestrian injuries that do occur tend to be less serious thanks to the relatively low speeds demanded by modern roundabouts.

What about visually impaired pedestrians?

Roundabouts may have an advantage to the visually impaired because they only have to address a single direction at one time and they can more easily distinguish between the vehicle noises. Also, slower vehicle speeds are generally safer for pedestrians.