To: Honorable Mayor and Members of Town Council
Through: David L. Corliss, Town Manager
From: Daniel Sailer, Public Works Director
Title
Discussion/Direction: Neighborhood Traffic Calming Program Amendments
Body
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Status Summary
Staff have compiled information on the current status of the Neighborhood Traffic Calming Program (Program) (Attachment A), a neighborhood resident driven program that has been in place since 2007 with one revision in 2015. The purpose of the Program is to provide residents and staff a consistent, feasible, and manageable procedure for addressing neighborhood traffic concerns on residential streets where documented speeding problems or other traffic factors exist that may adversely affect the overall residential quality of life. A comprehensive review of all aspects of the current program is provided (Attachment B) the following is a summary of this review.
In 2012 the Town’s Transportation Design Criteria Manual was updated to require developers to install traffic calming treatments on residential streets when a certain length of uninterrupted travel (no significant curves or intersection control) exists. This has resulted in several installations of traffic calming devices shown on the attached map (Attachment C).
The Neighborhood Traffic Calming Program is considered a quality of life program by staff. While concern about safety is consistently cited as the reason to construct traffic calming treatments, it is important to start with how we distinguish the two. There is no question that vehicle speeds can pose a safety risk. The severity of vehicle speeds on injury severity when a cyclist or pedestrian is involved has been well studied nationally. Severity of incidents in these cases dramatically increases with higher speeds (typically above 20 mph see Figure 1). Ninety percent of pedestrians survive being hit by cars traveling at 20 miles per hour. At 30 mph, that drops to 50%. In reality, the practicality of designing streets to force all drivers to travel at this speed, or lower, is cost prohibitive. Streets that are designed to handle higher speeds that are posted appropriately, and have appropriate sight lines are considered to be a safe driving environment. Additionally, traffic incidents occur as the result of three general reasons: 1) Driver behavior, 2) Vehicle condition, and 3) Roadway environment. Staff utilizes statistical analysis to help us understand if the roadway environment is a potential contributing factor. This is how staff technically defines a safe driving environment. High Safety is a value we know the community desires to maximize in all of our programs. The Town has other programs that address crash and capacity issues that affect safety. If staff is made aware or identifies a safety issue that can be addressed with physical improvements, a targeted project is created and implemented with other community priorities.
Figure 1. FHWA chart of vehicle impact speed verse pedestrian injuries
When the roadway environment has an appropriate speed limit posted, as required by State law to be determined by an engineering evaluation if differing from the Model Traffic Code, and incident history does not indicate that the roadway environment is a contributing factor, then concerns about speed fall into a quality of life concern. Safety risks still exist in this case, but the probability of incidents occurring are lower. The existing Neighborhood Traffic Calming Program is built on this premise. Its goal is to assist neighborhoods that have a shared perspective on what their comfort level with vehicle speeds are.
The map provided shows the streets that have had traffic calming treatments installed since the program’s inception in 2007. We receive several inquiries about traffic calming, 10 in the last six months. An average of five petitions per year have been received in the Program over the last seven years, which has resulted in two infrastructure projects. In one other instance, a petition case met the threshold criteria and then through an education and outreach effort, speeds reduced, so the project was deemed complete and no further action was needed. For both infrastructure projects, speeding 5 MPH or more over the speed limit by a significant majority of drivers has been reduced by 7 to 14 MPH and to within the posted speed limit. The other petitioned streets did not meet the speed or traffic volume threshold for the Program. In all instances where vertical treatments were installed, speed reduction of the driver population was achieved.
Staff reviewed other similar jurisdiction programs. Compared to other programs, the Town’s is currently the most accessible to residents for mitigation measures of any of the programs reviewed. From our review of other communities, our conclusion is Castle Rock’s current program is working well and effective at slowing traffic when projects are implemented. Staff recommends keeping the current Program in place, and expand the program to include:
Modify the approval process for collectors with no direct driveway access to be determined by Town Council with input from the broader community.
Allow for neighborhoods that don’t meet the program criteria to privately fund improvements only if the surrounding neighborhood supports their installation as defined in the current program. Since staff review would be needed for all privately funded projects, it’s recommended that our current private development review fees be considered to apply to each application.
History of Past Town Council, Boards & Commissions, or Other Discussions
There will be a presentation on February 6, 2023 to the Public Works Commission to obtain the Commission’s recommendation to Town Council on this matter. An update on their recommendation will be provided at the Town Council meeting.
Attachments
Attachments:
A- Current Town Council Approved Program
B- Comprehensive review of Program
a. Program Purpose
b. Why this is not a “Safety” Program
c. Features of the Current Program
d. Request and Budge Status
e. Current Request Needs
f. Other Jurisdiction Programs
g. Project Performance
h. Recommendations
C- Map of Traffic Calming Devices