Traffic Calming Program

Thank you for taking the lead in helping make your neighborhood streets safer.

As a Petition Sponsor, you play an important role in representing your neighborhood and helping start the traffic calming process. This toolkit is designed to guide you through each step

Traffic-Calming-Handbook-2026.pdf(PDF, 881KB) 

Traffic-Calming-8-Step-Guide.pdf(PDF, 148KB)

Get to know the 85th percentile speed analysis(PDF, 226KB)

Traffic-Calming-Request-and-Petition (Print)(PDF, 102KB)

Facts to Know about the Traffic Calming Handbook

To request a traffic calming study, residents must submit a formal petition using the “Traffic Calming Petition Request” form. The form can be obtained by clicking the link or contacting the Public Works Department at (303) 289-8150.

Step 1(a): Within 21 business days, staff will contact the Petition Sponsor to schedule a neighborhood meeting as detailed in Step 5.

Once a petition is received, staff begin by developing an education and outreach plan focused on increasing speed awareness in the neighborhood. This may include signage, targeted enforcement, and other awareness efforts.

Residents are encouraged to review the Traffic Calming Handbook and share feedback on the traffic calming measures they believe would help reduce speeds or improve safety in their area.

Staff will also outline each step of the study process to ensure there is a clear, shared understanding of the analysis, possible outcomes, and upcoming neighborhood meetings.

Please note:

• The Traffic Calming Request form includes a petition with signatures from at least 50% of affected households.
  • Traffic-Calming-Request-and-Petition.pdf(PDF, 102KB)
  • Helpful Tip: While the petitioner initiates the request, they do not have to gather signatures alone. Neighbors may help canvass the area to collect signatures from at least 50 percent of affected households to begin a review of the request under the city’s established criteria.
• The Traffic Calming Handbook applies only to local and collector roadways.
• A new traffic calming study may be requested after twelve months, or sooner if traffic conditions change significantly.

Once a street is confirmed as eligible for traffic calming, Public Works defines the study area and begins data collection. 

• The City uses a radar-based traffic data collector (JAMAR) to measure vehicle speeds and traffic volumes.
• Only one JAMAR unit is available, so it is deployed for one full week at a time.
• After the collection period, the data is compiled and reviewed by City staff to ensure accuracy and completeness.

Data collection consists of one or more areas: 

• Speed Data: 
  • 85th Percentile Speed (speed below which 85% of vehicles travel).
  • Spot speed surveys to measure actual speeds and violations.
• Traffic Volume:
  • Average Daily Traffic (ADT) counts for at least 24 hours.
  • Peak-hour volumes.
• Cut-Through Traffic:
  • Origin-Destination (O-D) Studies to identify non-local traffic (license plate matching during peak hours).
• Crash History:
  • Review of crashes over the past 12 months, focusing on pedestrian, bicycle, and speed-related incidents.
• Roadway Conditions:
  • Alignment, grade, parking, and existing traffic control devices.
• Pedestrian/Bicycle Activity:
  • Observations of non-motorized users in the study area.

Data is compared against threshold values to determine if a problem exists:

• Speed Analysis:  
  • < 3 mph over limit → No engineering measures.
  • 3–5 mph over → Education & enforcement.
  • 5 mph over → Education + enforcement + engineering (e.g., speed humps on local streets).
• Cut-Through Traffic:
  • Cut-Through Traffic: Traffic calming may be considered if 30% or more of the vehicles using the street each day are drivers passing through the neighborhood rather than starting or ending their trip there.
• Volume Thresholds:
  • Average Daily Traffic (ADT): More than 800 vehicles travel the street per day, or more than 150 vehicles travel the street during the busiest hour (on residential streets).
• Crash Analysis:
  • Crash History: A location may be considered high concern if three or more crashes involving pedestrians or bicyclists occur within a one-year period.

Studies exclude holidays and atypical traffic periods to ensure accuracy. Studies being conducted in school zones must be done while school is in session.

Emergency Services Review: All proposed traffic calming measures must be reviewed and approved by Police and Fire departments to ensure emergency response access is not compromised. If emergency access would be compromised, traffic calming would not be warranted. 

Thresholds for Traffic Calming 

Warranted When: 

•  The typical top speeds (85th percentile) are more than 5 mph over the posted speed limit.
•  At least 1% of drivers are traveling more than 15 mph over the posted speed limit.
• Crash history includes incidents involving pedestrians or bicyclists.
• Cut-through traffic accounts for 30% or more of the total daily traffic.
• More than 800 vehicles use the street per day, or more than 150 vehicles use the street during the busiest hour.

Not Warranted When: 

•  Speeds are within 3 mph of the posted limit. 
•  Traffic volumes and crash rates are below established thresholds.
• The measures would interfere with emergency response, snow removal routes, or transit service.
• The roadway has a grade of 8% or greater, is classified as an arterial street, or serves as a designated truck route (speed humps are not permitted in these locations).

What happens when the data analysis is completed? 

If the warrants are met: Move on to Step-Four.