State 55 Hwy at KK County Hwy operational benefits compared to conventional intersections. significant provide also They bicycles. and pedestrians including users, all for safety to improve designed are Roundabouts life. of loss or injury in result that crashes of types the reduce Countermeasure FHWA identified roundabouts as a roundabouts along rural highways throughout the state. other with forward move them helped WisDOT, and for a success project this made crashes in reductions significant These fatalities. zero and injured person one in 11 resulting have been crashes total there reports WisDOT construction, after period six-year the In accordingly. speed their toreduce and advance, in well roundabout the recognize drivers help features and pavement markings, along with enhanced signing. These high-speed approaches by providing longer splitter islands the for account to design the modified They a roundabout. as intersection the toreconstruct decided WisDOT 2006, In tooccur. continued crashes but to45 mph, limits speed posted approach the lowered and KK CTH of 55 advance in STH along signs warning intersection The Wisconsin of Department Transportation added (WisDOT) killed. person one and injured 17 in resulting people intersection the at (2001-2005),occurred period crashes 30 afive-year In approach. each on limit speed a55 posted mph with intersection controlled stop- atwo-way originally was KK) (CTH KK Trunk Highway Trunk55 55) State of County (STH Highway and intersection The County,Calumet Wisconsin because of their ability to substantially to substantially ability their of because Proven Safety Safety Proven 2. efficient than other types of circular intersections. circular of types other than efficient rotary. Roundabouts have proven been safer and more large or circle traffic unlike aneighborhood is quite but intersection, circular of is atype A roundabout Roundabout?What a is 1. features: essential distinguishing have certain Roundabouts 3. circulation Counterclockwise Apron island Splitter roadway Circulatory crossing pedestrian Accessible yield to traffic already circulating. already to traffic yield Control. Yield Entry wise around a center island. acenter around wise Counterclockwise Flow. Low Speed. Speed. Low speeds throughout the roundabout. the throughout speeds Cover image source: Washington of State Department Transportation (WSDOT) Figure 1. 7 20. 5 45.4367 or Center FHWA Resource PhD P.E., Isebrands, Hillary 2 02 .7 3 8 .7 7 93 or Safety FHWA of Office Shaw, PTP PTOE, Jeffrey P.E., For MoreInformation visit: please roundabouts, To about more learn Publication numberFHWA-SA-14-097 UPDATED jULY 2020

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Source: WSDOT

ROUNDABOUTS & Rural Highways&

Common Problems/Concerns Why Consider a Roundabout Real World Results*

Crashes at rural intersections often involve high Roundabouts are geometrically designed for Roundabouts constructed at intersections along speeds, which tend to result in severe injuries or drivers to negotiate the intersection at speeds in high-speed, two-lane rural highways reduced fatalities. Roughly 1/3 of annual intersection fatalities in the range of 15-25 mph, regardless of the posted overall crashes by up to 68% and reduced injury the U.S. occur along rural, two-lane highways. speed limits on approaches. crashes by up to 88%.

In many rural environments, drivers can miss a stop Because roundabouts require vehicles to yield and Roundabouts constructed at intersections along sign or traffic signal, leading to running through a then navigate around a raised, circular island, the high-speed, two-lane rural highways eliminated stop sign or red light and resulting in an angle crash. possibility of an angle crash is significantly reduced. 83% of angle-type crashes.

For a driver turning left across oncoming traffic, it With roundabouts, there is no need to make a turn There were 11 fatal crashes in the 5 year “before” can sometimes be difficult to judge the speed of the across opposing traffic. Entering vehicles yield to period and ZERO fatal crashes in the 5 year “after” approaching vehicle, resulting in misjudged gaps, traffic already in the circle, and proceed when there period at 19 roundabouts constructed along high- and potentially severe crashes. is a safe gap. speed, two-lane rural highways in six different states (KS, MD, MN, OR, WI, and WA).

It doesn’t seem like people would slow down for a High-speed approaches to roundabouts include Researchers compared traffic speeds of approaches roundabout along rural highways. Motorists will just advance signing, pavement markings and raised to roundabouts and stop-controlled intersections. drive right into or over the roundabout because they channelization. With proper design, drivers adjust At 100 feet before the yield or stop lines, the speed won’t be able to slow down in time. their speeds, slow on approach, and navigate the of traffic at the roundabouts was 2.5 mph lower roundabout safely. than at the stop-controlled locations.

In the northeastern U.S., circles are being signalized The old traffic circles and rotaries that are Roundabouts are designed for slower speeds, or removed because they do not work. common in the northeastern U.S. are not modern require entering traffic to yield to vehicles already roundabouts. in the circular roadway, and to eliminate the need to weave or change lanes to exit.

Why build something “different”, when all that is Improvements like stop signs and signals, while Since the late 1990s, an ever growing number of needed is either stop signs or a traffic signal? very familiar, aren’t always the safest choice. With State DOTs and local road agencies are finding intersections representing about one-quarter of that roundabouts work in their jurisdictions. Their annual U.S. traffic fatalities and roughly half of potential for saving lives is too significant to ignore. all injury crashes, safer designs are needed that improve mobility while saving lives.

* Sources: Isebrands, H., S. Hallmark, N. Hawkins. “Effects of Approach Speed at Rural High-Speed Intersections “ Transportation Research Record: Journal of the Transportation Research Board, Volume 2402, Transportation Research Board, National Research Council, Washington, DC, 2014

Isebrands, H. and S. Hallmark. “Statistical Analysis and Development of a Crash Prediction Model for Roundabouts on High-Speed Rural Roadways” Transportation Research Record: Journal of the Transportation Research Board, Volume 2389, Transportation Research Board, National Research Council, Washington, DC, 2012