Traffic Calming
Traffic Calming
Consultation has concluded.
Traffic Calming
Pilot program background
The City of Arvada's 2017 Bicycle Master Plan(External link) made a recommendation for the City to complete a multi-modal study of W. 57th Avenue, which was completed in 2020. From the study, the City determined recommendations to improve mobility and safety for people biking, walking and driving along the corridor. The City Council further directed staff to evaluate and develop a similar traffic calming plan for Grandview Avenue before implementing any changes to W. 57th Avenue.
City staff collected speed and volume data at six different locations along the corridor and developed a plan to reduce speeding based on this information. This plan began a pilot program(External link) with the installation of traffic calming devices, speed humps and traffic circles along the corridor. The current devices are a lighter, faster option that could be installed and tested quickly. More permanent devices may be installed in the future should the pilot program be deemed successful in this area.
Community feedback on the pilot program
Data collection on the current installations has continued through the summer of 2023. From April-July 2023, the City Traffic team also conducted the first traffic calming survey that asked for general, ongoing feedback about the devices that were installed this year.
In August 2023, the project team invited community members to offer more detailed feedback about their experiences with the traffic installations in a second survey that included additional questions, such as the opportunity to share their perceptions of safety and comfort. Even if a community participated in the first traffic calming survey, the project team encouraged any community member affected by these installations to submit feedback through this final survey.
Thank you to those who shared their feedback with the project team! This feedback is being considered alongside a variety of speed and technical data to understand the future of this area. A final report and recommendations to City Council are anticipated for early 2024. Please stay tuned for future updates as they become available.
Types of devices in the pilot program
Traffic circles
Traffic Circles are speed management tools installed at small scale (one lane in each direction) intersections along roadways that are posted at 25 to 30 MPH. They are similar to roundabouts in terms of directing motorists slowly around a center circle.
Speed cushions
Speed cushions have two or more raised areas with gaps between. These are similar to speed humps with spacing of the gaps to allow emergency vehicles to pass through at higher speeds.
Curb extensions
The curb extensions involve the installation of flexi-posts, white striping and temporary colored paint in an effort to reduce the crossing distance for pedestrians, improve sight lines for drivers and reduce speeds of drivers turning.
Pilot program impacts
Data gathered so far shows the speed of traffic has slowed down
Prior to installation of speed cushions and traffic circles, staff conducted speed studies at or near several intersections along both corridors.
The 85th percentile speed is the speed at which 85 percent of drivers are traveling at or below through a roadway segment. This information is used in traffic engineering practices for analyzing streets. The remaining 15 percent reflects emergency vehicle operators that are allowed to travel at higher speeds or unlawful behavior of drivers traveling beyond the safe and reasonable design of the road. The table below uses 85th percentile data to demonstrate the speed change once traffic calming devices were installed. This data shows a significant decrease in speed at most locations.
| Locations | Pre-pilot speed | Speed Change |
|---|---|---|
| W. 57th and Carr | 33.9 mph | down (-) 9.3 miles per hour (mph) |
| W. 57th and Dudley | 35.9 mph | (-) 6.6 mph |
| W. 57 and Yukon | 28.0 mph | (-) 5 mph |
| Grandview and Balsam | 34.5 mph | (-) 15.2 mph |
| Grandview and Cody | 34.8 mph | (-) 3.3 mph |
| Grandview and Everett | 37.5 mph | (-) 8 mph |
| Grandview and Flower | 36.8 mph | (-) 4.7 mph |
| Grandview and Yarrow | 28.5 mph | up (+) 3.1 mph |
Observations of Traffic Circle effectiveness indicate improved safety
Video footage was collected to understand driver compliance with traffic circles. This was done during peak hour traffic at the intersection of W. 57th Avenue and Balsam Street between February 14, 2023 and February 17, 2023.
The majority of motorists were found to be navigating the traffic circle as designed. School buses, snow plows, trash trucks, and emergency vehicles were observed navigating through the traffic circle without issues.
Some common concerns and challenges from the traveling public in the area that were observed to be addressed through the installation of these devices include:
Intersection Sight Distance: Parking issues were resolved at Traffic Circle installation locations including at the school drop-off and pick-up areas.
Bike and Pedestrian Safety: All movements now yield to cyclists and pedestrians; some confusion still exists at school dismissal when no crossing guard is present.
Traffic Movements: Traffic slows down while also flowing continuously.
Over 99% Compliance Rate: Review of traffic circle video showed over a 99% compliance rate during peak hour traffic.
All Speed Cushions are secure and effective
Each speed cushion has 16 parts that are securely fastened to the road. Of the 128 total sections of the speed cushions, to date, there have been two sections that needed repair or replacement. As such, the success rate from a maintenance perspective after one winter season is 98.5%.
Who's Listenting
Kellee Van Bruggen
Bicycle and Pedestrian Coordinator
City of Arvada
Katie Patterson
Infrastructure Communications Manager
City of Arvada
| Email: | pw_workzone@arvada.org |
Frequently Asked Questions
Approaching drivers must yield to traffic within the Traffic Circle and wait for gaps to proceed. In the traffic circle, drivers must proceed with caution yielding during turns for drivers, pedestrians, and cyclists.
Here are a few tips:
Similar to traditional intersections, follow Yield or Stop signs and proceed to the right when safe.
Passenger vehicles should not turn left cutting through a traffic circle.
Only buses, emergency and oversized vehicles are allowed to make left turning movements.
Drivers should use turn signals and follow posted speed limits and signs to safely navigate the traffic circles.
Stop signs and traffic signals are used as traffic control devices to help with traffic volumes and flow of traffic. Traffic calming devices help limit speeding by slowing down the flow of traffic.
Traffic circles are a tool used on less trafficked neighborhood roads and are smaller than roundabouts.
The City’s Mobility Planning and Innovation (MPI) Division has been piloting devices such as traffic circles and speed humps that can help slow traffic to enhance pedestrian, cyclists, and driver safety. These strategies are part of an ongoing effort to improve the connectivity and walkability of our city.
The MPI Division is using test projects to determine the effectiveness, obtain neighborhood feedback, and develop designs using input from the police and fire departments, road maintenance crews, and plow operators.
The pilot program is anticipated to run until the end of 2023. In October 2023, city staff will present results of the pilot program to the City Council for direction on the next steps.
We are currently still in the pilot phase along the W. 57th Avenue and Grandview Avenue corridors. After evaluating the effectiveness of the program, City staff will present the findings to the City Council in the Fall of 2023. If a program is to be developed, more information will be provided on Speak Up and the City in late 2023/early 2024.
The current pilot program cost is $6 per linear foot of roadway within the study area. This allows us to trial the effectiveness of these devices through a “lighter, quicker, cheaper” method. A more permanent solution would cost approximately $200 per linear foot of roadway and potentially more should the solution not be effective and need to be removed.
The Public Works Department will present the pilot program results to the City Council in October 2023. The recommendations will be for one of two options:
If successful, the “lighter, quicker, cheaper” installation will be maintained until a pavement resurfacing project incorporates the designs into a permanent design.
If unsuccessful, the traffic calming devices will be removed and the street will be restored to the original design.