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Welcome
Ada County Highway District Logo
Welcome to the second online meeting for the Ten Mile Road and Deer Flat Road roundabout project.
The purpose of this online meeting is to give you an opportunity to:
Review the revised design
Review the feedback we received during the first public outreach in September 2023
Share what you think
Satellite map outlines the project area limits (which span from Crenshaw Street, Kolnes Avenue, Wasabi Avenue and Ingo Street).
Project Description and Purpose
ACHD is proposing to replace the stop-controlled intersection at Ten Mile and Deer Flat with a roundabout. The design includes the following:
Two northbound and two southbound lanes on Ten Mile Road
A single eastbound and a single westbound lane on Deer Flat Road (with a dedicated westbound right-turn lane)
To see what the intersection at Ten Mile and Deer Flat roads looks like now, and what it will look like in the future, move the slider arrows on the graphic.
Aerial view of the project area. A slider tool allows user to compare a current view of Deer Flat and Ten Mile Road intersections and a view of the future roundabout (including truck apron, pathway buffer, multi-use pathway, median, and RRFB locations).
Key features include:
A 10-foot-wide multi-use pathway
Rectangular rapid flashing beacons (RRFBs) at all crosswalks
A truck apron for larger vehicles
Intersection lighting
Curb and gutter
Bike ramps at Deer Flat/Kolnes Way to transition bikes from the multi-use pathway to the roadway
Updated pedestrian ramps to meet current standards
Aerial graphic depicting the future roundabout (including labels for truck apron, pathway buffer, multi-use pathway, median, curb and gutter, and RRFB locations).
Project Purpose
The project is needed to accommodate future traffic growth while safely accommodating all users, including pedestrians and cyclists.
Learn more about traffic growth and volumes below.
Graph outlining traffic volume counts for peak traffic times (morning and evening). Counts for the current year (2023) and a projection of the future year of 2040 are shown. Morning 2023 = 1,500. Morning 2040 = 1,550. Evening 2023 = 1,550. Evening 2040 = 1,800.
Click image to enlarge
Aerial view of project area with the future roundabout that shows property lines and street names.
What We Heard
In September 2023, ACHD reached out to the public to gather feedback on the design. For more information, view a summary of what we heard.
Graphic depicting September 2023 Public Meeting survey answers to the question: What do you think of the project design? 163 = Strongly dislike it. 50 = Love it. 42 = Like it. 35 = Dislike it. 13 = Neither like or dislike.
Graphic depicting September 2023 Public Meeting survey participation numbers. Total Online Visits = 1,300 Survey Responses = 300 Emailed Comments = 6
Major Themes
Pedestrian safety
Concerns for the safety of pedestrians, including students and cyclists crossing the roundabout.
Construction Impacts
Concerns about access and other impacts during construction, and the time it will take to build the roundabout.
Is a roundabout needed?
Questions about whether a roundabout is the right solution for the intersection. Some commenters believe that traffic volumes are too low and pedestrian traffic is too high for a roundabout.
What's Changed?
As a direct result of concerns expressed for pedestrian and cyclist connectivity and safety, ACHD extended the multi-use pathway to the Pedestrian Hybrid-Beacon (PHB) crossing at West Crenshaw Street.
As an additional safety measure, the speed limit on the roads near the roundabout will be reduced to 35 mph.
Roundabout Safety
Providing safe facilities for all users is our top priority at ACHD and we want your family to be just as safe as ours when walking, biking, and driving in Kuna, especially around schools.
With that in mind, Rectangular Rapid Flashing Beacons (RRFBs) are included in the Ten Mile and Deer Flat roundabout. See graphic below.
Graphic depicting a driver view of an RRFB crossing traveling northbound along Ten Mile toward the roundabout. Graphic includes a pedestrian, vehicle, and bicyclist.
Driver’s perspective travelling Northbound along Ten Mile.
RRFBs have been shown to enhance safety at roundabouts in the following ways:
Increases Visibility
The rapid alternating flashes of light alert drivers to the presence of pedestrians. The irregular flashing lights can increase motorist yielding rates by 98%.
Enhances Crosswalk Safety
Pedestrians activating the RRFB create a visual cue prompting drivers to slow down, which can reduce pedestrian-related crashes by 50%.
Gives Pedestrians Control
Pedestrians activate the beacon when they intend to cross.
Benefits of Roundabouts
Studies show properly designed roundabouts improve safety by:
Requiring pedestrians to cross one direction of vehicle traffic at a time
Reducing the number and severity of injury collisions – most importantly, fatal crashes
Reinforcing slower speeds near school zones (circular design forces drivers to slow down)
Reducing conflict points
Current Ten Mile and Deer Flat Road stop-controlled intersection with 31 conflict points (left).
Proposed Ten Mile and Deer Flat Road roundabout with 19 conflict points (right).
Roundabouts have been implemented near the following schools:
City
School
Boise
Hillside Junior High School
Caldwell
Vallivue High School
Caldwell High School
Sage Valley Middle School
Desert Springs Elementary School
Nampa
Columbia High School
Middleton
Middleton High School
Mill Creek Elementary School
Q: Will the roundabout be safe for school children, pedestrians, and bicyclists?A: Roundabouts force drivers to slow down, reducing the risk and severity of accidents. The Rectangular Rapid Flashing Beacons (RRFBs) and crosswalks provide safe crossings because pedestrians only cross one direction of traffic at a time and are more visible to motorists.
Construction timeline graphic (with clock and safety cone)
Q: How long will construction activities take? Will the intersection be closed?A: Construction will take approximately 6-8 months, assuming there are no delays caused by weather or other unforeseen circumstances. The Ten Mile and Deer Flat Road intersection will likely be closed to accelerate construction.
Triangular shape roundabout graphic with arrows
Q: Is a roundabout needed at this intersection? Vehicle traffic volumes are low and pedestrian traffic is high.A: A recent traffic study shows the current intersection cannot safely handle future traffic growth. The study recommended a multilane roundabout to manage future traffic flow.
Traffic signal light displaying red, yellow, and green lights.
Q: Why not install a traffic signal instead?A: As part of the traffic analysis, a signalized intersection and a roundabout were evaluated. The roundabout was the preferred option because it provides continuous traffic flow that reduces delays and improves safety for all users.
Circular icon including a pedestrian and bicycle to represent benefits of multi-use pathway question and answer.
Q: What is the benefit of providing multi-use pathways?
A: Multi-use pathways are two-way facilities meant to accommodate both pedestrians and bicyclists of a wide range of ages and abilities. They provide more space between motorists and those walking and biking, which increases safety.
Timeline
Project timeline depiction outlining design phase (2022 to mid-2024), Public Information Meeting #1 (Fall 2023), Public Information Meeting #2 - WE ARE HERE (Spring 2024), Property purchasing activities (Fall 2024), and Construction (Fall 2026 – Summer 2027).
Nearby Projects
ACHD has several improvements planned for the area.
