Ada County Highway District

36th Street/Hill Road/Catalpa Drive Roundabout

General Description:



We are almost finished!

Thank you for your patience as we work to finish the roundabout. We just have a few more things to do!

Hill Road Closure

  • Starting on Wednesday, May 25, Hill Road west of 36th Street will be temporarily closed while crews construct the western section of the roundabout. The closure will last for approximately one week.
  • Local, business and emergency access will be maintained at all times.

Night Work

  • On Wednesday, May 25 and Thursday, May 26 crews will work thru the night to pave the intersection.

We apologize for any inconvenience this work may cause and appreciate your patience as we finish constructing the roundabout. The temporary closure and night work will allow crews to finish the project ahead of schedule.

All work is weather permitting.



5/13/16: Hill Road closure starting on Wednesday

Starting on Wednesday, May 18, Hill Road, east of 36th Street will temporarily close while crews construct the eastern section of the roundabout. Local, business and emergency access will be maintained at all times.

The temporary closure will allow crews to finish this project ahead of schedule while maintaining a high level of safety for motorists, bicyclists, and pedestrians.

This section of Hill Road will reopen in approximately one week, weather permitting. Once this particular section of Hill Road is complete, crews will temporarily close the portion of Hill Road west of 36th Street for approximately another week. When both closures are complete, paving will occur overnight for two nights. Paving will tentatively take place toward the end of the month.

We understand that this closure will present an inconvenience to the traveling public; however, we believe that this is the most convenient option for motorists. The other alternative involved lane restrictions with heavy flagging, which would have resulted in major delays for motorists.

Crews are ahead of schedule for completion of this project, and we appreciate the public’s patience while we work to create a safer, smoother, longer lasting intersection for all users.



3/16/16: New detour starting in April

Construction over spring break


  • During the week of March 21, crews will continue to work on the roundabout, but will also take advantage of school being out and start work on the entrance and exit of Hillside Junior High. While most of the school driveway work will be complete by the time school starts again on March 28, please note that the driveways will likely be gravel.

New detour

  • The first week of April, crews will begin building the north half of the roundabout. As a result, travel through the intersection will change significantly. Click on map below to view a larger image.


New project manager

  • Brian McCarthy will be taking over as the new ACHD project manager for the project. He is dedicated to maintaining a high level of customer service and looks forward to working with the neighborhood.


    1/8/16: Changes beginning Sunday

    West leg of Hill Road

    • On Sunday, January 10th, the west leg of Hill Road at 36th Street will be closed to through traffic to allow crews to repave the area where pipe was recently laid. Motorists will be detoured to Collister, but residents along Hill Road will still be able to access their homes from the west. Hill Road is expected to be reopened by Monday morning, along with 36th Street north of Hill Road.

    Changes starting Monday

    • On Monday, January 11th, crews will begin building the south half of the roundabout. As a result, travel through the intersection will change significantly. Starting Monday:
      • 36th Street will reopen.
      • Catalpa Drive will close between N. Garden Center Way and 36th Street.
      • On Wednesday, 36th Street between Garden Center Way and Hill Road will close.
      • The bypass (see below) will go into effect and the traffic signal will be removed.


     For larger map, click on image above.


    West leg of Hill Road to close

    Just a reminder that the west leg of Hill Road will be temporarily closed this weekend as crews continue to work on the Stewart Gulch portion of the construction project. This portion of Hill Road will be reopened by Monday morning.

    Thank you for your patience!


    Did you miss the December 10th open houses?

    If you were unable to join us at the construction open houses on December 10th, all the materials and handouts can be found under "Related Documents" on the right side of your screen. If you have children that walk to and from school, click on the image below to watch the construction video!


    Stay in the loop!

    • Sign up to receive email updates: Fill out the form under "Subscribe" on the right side of your screen.
    • Weekly construction coordination meetings: Meetings will be held Thursdays at 10 a.m., at the old sewer building on the NW corner between Hill and 36th. The public is welcome to attend.
    • Monthly community meetings: Join us the second Monday of every month from 5:30-6:30 p.m. at the 36th Street Garden Center & Bistro. First meeting is January 11th.


    Construction to start as early as December 28, 2015*

    The Ada County Highway District (ACHD) anticipates beginning construction on the 36th, Hill, Catalpa roundabout as early as December 28th*. The project is expected to be complete by August 2016.  With the intersection being the nexus of a bustling neighborhood and shopping center, popular with bicyclists and home to Hillside Junior High School, safety will be our highest priority. With your patience and cooperation we can make the construction go as safely and efficiently as possible.    *weather dependent


    What can neighbors expect during construction?

    Construction can be challenging and ACHD is working to minimize how it will impact businesses, neighbors, and the traveling public.

    • Work is anticipated to occur between 8 a.m. and 7 p.m. on weekdays, with some weekend work when necessary.
    • Access to Hillside Junior High will remain open at all times during school hours. If business access will be impacted, the contractor will coordinate with adjacent businesses.
    • Pedestrian routes will be clearly defined.
    • The work will include, but not be limited to, general construction noise, dust, equipment back up alarms and ground vibration.
    • Businesses will remain open during construction.
    • Specific detour routes will be in place for bicyclists.
    • Road closures are expected.
      • Catalpa Drive will be closed at the intersection until August 2016.
      • 36th Street, north of Hill Road, is planned to be closed starting December 28th for approximately two weeks while crews complete irrigation work. The west leg of Hill Road will be closed on weekends during this period. During this closure the private access gate between W. Bison and N. Cartwright Road will be open to the public. The gate will close after the 36th Street work is complete.
      • While we will try to keep Hill Road open as much as possible, there may be times when the roadway must be closed.


    Watch the video to learn how the new intersection will work!

    Click on the image below to see how those that bicycle, walk, and drive will navigate the new roundabout.


    Utility work to start on 36/Hill/Catalpa Intersection

    10/2/15 Update: Utility work is starting in the area next week (October 5). Probst Electric will begin utility work on 36th Street between Shasta Street and Hill Road and Knife River will also start their work on Hill Road between 34th Street and Whitehead Street. The utility work is permitted from 8 a.m. to 7 p.m.

    At the same time, as part of the 2015 Overlay Projects, Catalpa Drive between Collister Drive and Garden Center Way is receiving an overlay (road resurfacing). Work on this project is permitted weekdays between the hours of 9 a.m. and 4 p.m., and 6 p.m. and 10 p.m. Weekend work is also permitted between the hours of 7 a.m. to 10 p.m. The overlay work will continue until mid-October.


    As early as September 28th utility work will begin in preparation for the construction of the 36th Street, Hill Road, Catalpa Street roundabout project. The goal is to have the utility work completed before construction on the roundabout starts. This will help construction go more smoothly.


    What can neighbors expect during the utility work?

    • Crews will be removing a tree on ACHD's property located on the northwest corner of the intersection. Idaho Power will also be moving power poles and trenching/boring to relocate the overhead lines underground. Most of this work will occur outside the existing intersection, but there may be temporary lane restrictions, with flaggers, when necessary.
    • United Water will begin installing a new water main along Hill Road beginning as soon as October 12th. At this time we anticipate lane restrictions, with flaggers, however short-term intersection closures may be needed.
    • Utility work is expected to occur between 8 a.m. and 7 p.m.

    When will construction start on the roundabout?

    We are working with the contractor to determine the best schedule; however construction could start as early as late November 2015. Once a schedule is determined we will have more information about construction impacts and what the neighborhood can expect. Sign up to receive email construction updates by filling out the form under "Subscribe" on the right side of your screen.


    We would be happy to answer any questions you might have about the utility work. Please email us at


    Learning about roundabouts

    Click to Learn more about how roundabouts work.


    June 26, 2014 Open House Materials

    Please click on the links below to review displays from the June open house. Learn more about roundabouts.


    April 24, 2014 Open House Materials

    Please click on the images below to review displays from the open house. More information on roundabouts can be found under "Related Documents" to the right of the screen.




Time Frame

Start Date:
December 28, 2015
End Date:
August 2016

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