- Public Works
- Roundabout U
"Roundabout U" is an outreach program of Washington County to provide guidance and information on a variety of topics related to roundabout design and usage, including instructions for drivers, pedestrians, and cyclists.
A modern roundabout is one of several types of intersections in which traffic flows around a circular center island. A modern roundabout is NOT the same as high-speed rotary interchanges, once common in the Northeast states. Rotaries are larger and operate poorly because they require merging to enter and require risky lane changes to exit. See Rotaries vs. Roundabouts (PDF). A modern roundabout also is NOT the same as a traffic circle or circle road, such as within the Tamarack Village shopping area in Woodbury, where lane changes may be made within the circle and circulating traffic makes right or left turns to exit the circle road. See Traffic Circles vs. Roundabouts (PDF).
At a modern roundabout, there is no merging because entering drivers must YIELD (wait until all traffic is clear before proceeding). There are no lane changes in a modern roundabout because, as with any other intersection, the correct lane must be chosen before entering. Always keep to the left to make left turns through a roundabout, just like at any other intersection.
Roundabouts have several advantages over signals and stop signs, including:
- Fewer injury crashes and fatalities (no “t-bone” or head-on crashes)
- Improved pedestrian safety (low speeds, fewer lanes to cross, minimal delays, traffic from only one direction)
- Less vehicle delay and pollution (no waiting at red lights, complete stops are not usually necessary)
Roundabouts within Washington County
- Hadley Avenue (CR 13) at State Highway 36 ramps in Oakdale (2 roundabouts)
- Radio Drive (CR 13) at Bailey Road (CR 18) and at Military Road (CR 20) in Woodbury (2 roundabouts)
- 34th Street North (CR 14) at Jamaca Avenue North and Stillwater Boulevard (CR 6) in Lake Elmo
- St. Croix Trail (CR 18) in Lakeland and Lakeland Shores (3 roundabouts)
- Woodbury Drive (CR 19) in Woodbury at Bailey Road (CR 18) and at Lake Road (2 roundabouts)
- Keats Ave S / Innovation Road (CR 19) at East Point Douglas Road in Cottage Grove
- 70th Street South (CR 22) at Hinton Ave S (CR 13), Keats Ave S (CR 19), and Jamaica Ave (CR 20) in Cottage Grove (3 roundabouts)
- 65th Street South (CR 74) at Goodview Ave S in Cottage Grove
- State Highway 36 at Hilton Trail (CR 29) in Pine Springs (2 roundabouts)
- State Highway 96 at Manning Avenue (CR 15) in Grant and Stillwater Township
- U.S. 61 at Broadway Avenue (CR 2) in Forest Lake
- U.S. 61 at 170th Street North (CR 4) in Hugo
- U.S. 61 at State Highway 97 in Forest Lake (2 roundabouts)
- U.S. 10-61 at Jamaica Avenue in Cottage Grove
- Headwaters Parkway at Fenway Avenue N in Forest Lake
- Along Hargis Parkway and Pioneer Drive in Woodbury (9 roundabouts)
- Hudson Road and Spring Hill Drive in Woodbury
- Hadley Avenue at Highway 36 North Frontage Road in Oakdale
- Bailey Road (CR 18) at Woodlane Drive in Woodbury
- Woodbury Drive (CR 19) at Dale Road in Woodbury
Benefits of Roundabouts
- Accommodates higher traffic volumes than traffic signals with fewer approach lanes
- Reduces delay during off-peak times; no waiting at red lights
- Reduces delay on side-street approaches
- Can improve travel times along a corridor
- Effectively handles u-turns for cars and large trucks
- Can provide better access to businesses because of easier u-turns
- Provides more landscaping opportunities
- Typically provides overall cost savings
- Allows for large vehicle passage via the "truck apron"
- Promotes slower speeds through intersection
- Provides reduced crossing distance, reduced delay, improved visibility and refuge for pedestrians crossing the roadway
- Snow removal can be handled by regular maintenance forces
- No traffic signal maintenance costs, electrical costs, or repair needs
- No traffic impacts during power outages
- Increases fuel savings due to less delay and stopping
- Reduces vehicle emissions due to reduced need for stopping
- Reduces construction area on approaches that can save trees
- Reduces stormwater run-off due to reduced pavement area on approaches
- Reduces vehicle crashes, particularly injury crashes (see below)
- Lowers vehicle speed
- Fewer driver decisions; traffic only comes from one direction when entering
- Fewer conflict points
- Reduces conflict severity; no right-angle or head-on conflicts
- Safer pedestrian crossings due to reduced distances, lower speeds, and better visibility
|Type of Roundabout||Converted From||Number of Conversions||Percent Reduction of all Crashes||Percent Reduction of Injury Crashes|
|Single Lane, Urban||Stop Controlled||12||69%||80%|
|Single Lane, Rural||Stop Controlled||9||65%||68%|
|Multi-lane, Urban||Stop Controlled||7||8%||73%|
Source: NYSDOT Study. October 2003.
Navigation of Roundabouts
- Reduce speed and prepare to stop if necessary; traffic within the roundabout has the right of way.
- Choose the proper lane for your intended movement as you approach the intersection. Failing to use the proper lane may cause a crash or result in a traffic ticket.
- Yield to pedestrians within crosswalks; never pass any vehicles, including bicyclists, when approaching or within the roundabout.
- Before entering the roundabout, look left and yield to all traffic within the roundabout. The inside lane of the roundabout is often allowed to exit and has the right of way.
- When traffic is clear, proceed into the roundabout, to the right of the circular island.
- Exit the roundabout at your desired exit point, again yielding to pedestrians within the crosswalk.
- Do not enter a roundabout alongside large trucks or buses with traditional intersections, they may encroach on other lanes to complete their turn.
- In an emergency vehicle approaches, proceed to your exit and then pull over. Do not stop or change lanes within a roundabout.
- Always stay on designated walkways. Never cross to the circular center island.
- Watch for cars. You have the right of way once you have safely entered the crosswalk, but your best protection is your own attention.
- Cross the roundabout one approach at a time, using the median island as a refuge prior to crossing the next direction of traffic.
- See also Pedestrian Safety (PDF) and Roundabouts and Pedestrians (PDF).
- If you are comfortable riding with traffic, cycle through the roundabout following the same rules as those for drivers.
- If you are not comfortable riding with traffic, use the paths and crosswalks following the same rules as those for pedestrians.