Public Works

Roundabouts 


Johnson Avenue NW Roundabouts
The project on Johnson Avenue NW stretches from 1st Avenue SW to Midway Drive NW. It includes pavement reconstruction (moving from 4 lanes to three lanes: two in each direction and a center turn lane); water main replacement, sanitary and storm sewer upgrades, and sidewalks and curb ramps. The project is scheduled in two phases over 2018 and 2019, and is being coordinated with the School District’s calendar.  Construction at Wiley Blvd will occur during summer 2018.  

Two single-lane roundabouts are proposed:

  • Johnson and Wiley
  • Johnson and Jacolyn Drive. 

School Safety
The roundabout planned at Johnson and Wiley in front of Hoover Elementary is a mini roundabout, and has been designed specifically with the school in mind:

  • It will include enhanced signage for pedestrians - a pedestrian friendly, flashing pushbutton system is included in the design, allowing the crossing guard to press a button for flashing lights 
  • Crossing guards are not being eliminated
  • It is smaller than a traditional roundabout, but can still safely accommodate buses
  • It provides pedestrian islands for those crossing the street
  • The crosswalk lengths will now be shorter, and pedestrians will only have to focus on one direction at time 
  • The design compels vehicles to reduce their speeds at the approach
Video Simulation
The simulation video below shows actual traffic volumes on Johnson Avenue NW, and renderings of how the roundabouts will operate. 




Kirkwood Blvd Roundabout
A new roundabout has been constructed at the intersection of Kirkwood Blvd and the Prairie Point Middle School entrance. The roundabout will help improve safety and traffic flow during peak morning and afternoon hours. Download the project FAQ for additional information. 

Video Simulation of Kirkwood Blvd roundabout

The video below illustrates a typical morning commute at the College Community School District. This simulation video is showing average traffic counts that are experienced during the morning drop-off period. 


Navigating a Roundabout

APPROACH
Slow down as you are approaching the roundabout. Yield to pedestrians in the crosswalk

ENTER
Yield to vehicles in the roundabout. Wait for a gap in traffic, and merge into traffic in the roundabout in a counterclockwise direction.

PROCEED
Continue through the roundabout until you reach your street. Never stop in the roundabout.

EXIT
Exit the roundabout to your right. Yield to pedestrians in the crosswalk.


Resources on Roundabouts


What is a Roundabout?

A modern roundabout is an unsignalized, circular intersection engineered to maximize safety and minimize traffic delay. Fundamental characteristics of all roundabouts include:

  • Counterclockwise Flow. Traffic travels counterclockwise around a center island
  • Entry Yield Control. Vehicles entering the roundabout yield to traffic already circulating.
  • Low Speed. Curvature that results in lower vehicle speeds, generally 15-25 MPH, throughout the roundabout

(video courtesy of Insurance Institute for Highway Safety)

Benefits of Roundabouts

SAFETY

  • Eliminates head-on crashes and right-angle crashes
  • Decreases severity of crashes
  • Reduces speeds 

TRAFFIC FLOW

  • Can move more traffic during peak hours
  • Reduces stops
  • Reduces delays
  • Reduces congestion 

ENVIRONMENT & COMMUNITY LIVABILITY

  • Reduced emissions
  • Reduced fuel waste
  • Fewer hard stops
  • Landscaping and beautification / neighborhood aesthetics 

ECONOMICAL

  • Longer service life
  • No signal maintenance 
  • Better long-term economic value

Sources: Iowa Department of Transportation, Federal Highway Administration, Center for Transportation Research and Education

© 2018  Cedar Rapids, Iowa, 101 First Street SE

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