City Staff Evaluation Process
Throughout the Traffic Forums process, Public Works identified several common key areas of traffic concerns. They include:
- Cut-through traffic and congestion
- School issues
- Roadway conduct
- Unique neighborhood concerns
Public Works and the Police Department have created the following outline on how the City will address each of these topics.
Speed limits and speeding concerns are evaluated by determining the 85th percentile on a roadway segment and is known as the prevailing speed. The 85th percentile speed is the speed at or below which 85 percent of vehicles are traveling. This value is used to set speed limits because studies have shown that speeds set at or near the 85th percentile speed of free flowing traffic are safer and provide the least variance in vehicle speeds. The City is required by governing documents such as the California Manual on Uniform Traffic Control Devices and the California Vehicle Code to evaluate speed limits within the City every five to seven years. If the 85th percentile speed is found to be different than the posted speed limit while conducting these evaluations, the governing documents listed above may require the posted speed limits to be increased or decreased. The effect of changing posted speed limits to accurately reflect the majority of vehicle driving patterns can be beneficial to build compliance with roadway signage and reduce the number of outlying speeders. This also allows police enforcement to focus on those outliers when issuing citations. The occasional speeder will vastly exceed the posted speed limit and can be very difficult to identify and cite. Therefore, traffic analysis will be conducted based on traffic patterns rather than individual vehicles.
The City is also able to approve and implement traffic calming measures on roadways where compliance with posted speed limits are desired. The primary guiding document to address speeding is the Neighborhood Traffic Management Program (NTMP), which was adopted by City Council in October 2006. The NTMP uses the “three E’s” approach of Education, Enforcement, and Engineering to mitigate neighborhood traffic issues. The “education” aspect of this approach allows City staff to conduct outreach to the neighborhood prior to moving on to the next steps of enforcement and engineering. Enforcement can also be conducted as another tool to address speeding.
Per the NTMP, the “engineering” aspect of traffic calming “is the combination of mainly physical measures that reduce the effects of motor vehicle use, alter driver behavior, and improve conditions for non-motorized street users.” The NTMP further defines two categories of traffic calming measures – Steps 1 and 2. Step 1 measures can be used on any City street and consist of low cost, less controversial tools such as portable radar speed display units, sign installations, and pavement striping changes. Step 2 measures can alter the roadway configuration, impede and deter traffic flow, and can be very controversial. These devices include speed cushions, traffic circles, and roundabouts. Step 2 devices are currently not allowed to be installed on collector or arterial roadways as defined in the Circulation Element of the City’s General Plan. Additionally, the General Plan includes a map of all street classifications in the city.
To evaluate speeding concerns, the City will conduct speed surveys using tube counters for two to seven days, depending on the characteristics of the roadway. The average prevailing speed will be determined from the study duration and will be used for the roadway analysis.
Where the average prevailing speed is less than or equal to 7 mph over the posted speed limit, the City can implement Step 1 devices. Additionally, targeted enforcement may be conducted during time periods identified in the speed study when the prevailing speed exceeds 32 mph.
Where the average prevailing speed is greater than 7 mph over the posted speed limit, the roadway qualifies for Step 1 devices as well as City-funded Step 2 devices. The procedures outlined in the NTMP will be followed to evaluate the appropriate Step 2 device for the roadway. Furthermore, strategic police enforcement will be conducted on the roadway, which will include rotating enforcement, as well as pre- and post-enforcement speed surveys.
Cut-Through Traffic and Congestion
Cut-through traffic and congestion will be studied on local streets using the guidelines defined in the Neighborhood Traffic Management Program. As defined in the NTMP, Step 2 traffic diversion devices include turn-restriction signs, median barriers, one-way street conversions, and sometimes roundabouts and traffic circles. Installation of these devices on local streets requires a minimum average daily traffic volume of 1,000 vehicles per day on local streets and at least 25 percent of vehicles must be “cut-through”.
Several different types of school issues arise primarily during drop-off and pick-up times. During these 15-30 minute periods on weekday mornings and afternoons, vehicle traffic on roadways near schools can significantly increase, sometimes beyond the capacity of those roadways. Some characteristics of these time periods are long vehicles queues at intersections, vehicles parking in red zones, on sidewalks, or double parking, and pedestrians walking in roadways.
Many of these issues have a two-fold approach. The City will work with schools to create circulation plans for use during drop-off and pickup times. In turn, the schools will need to work with parents so they comply with the proposed plan.
Another tool that can help relieve school congestion are staggered start times between two adjacent schools. This will allow one school’s drop-off or pick-up time to be offset with the adjacent school’s times in order to reduce the total number of vehicles traveling on adjacent roadways at the same time.
Roadway conduct includes, but is not limited to, concerns such as running stop signs or traffic signals, parking in red zones or on sidewalks, jaywalking, and blocking fire hydrants. The Police Department’s Volunteer Traffic Safety Corps, comprised of citizen volunteers, will conduct the initial assessment to determine peak times at which violations are occurring. This information will be utilized by the Police Department to conduct rotating targeted enforcement at the location. The Volunteer Traffic Safety Corps will conduct a post-enforcement survey to determine if violations have been reduced or if additional targeted enforcement is required.
Parking issues can arise when excessive amounts of non-resident vehicles park on residential streets for extended periods of time. The City adopted the Residential Parking Permit Program (RPPP) in January 2005 to address residential parking issues. Where approved, posted signage restricts parking for resident and non-residents to a 2-hour maximum, unless a parking permit is displayed. Community support and a neighborhood survey are required to install a parking permit zone.
Unique Neighborhood Concerns
Each neighborhood in the city has unique characteristics, which can cause various distinctive traffic issues. Characteristics include nearby land use and roadway classification and geometry. Each unique concern identified by the neighborhood will be addressed and assessed on an individual basis.
The City will review the top ten concerns individually along with relevant traffic data and propose improvements as described above. City staff will also review the top ten list as symptoms of potentially larger issues within the neighborhood and may propose additional improvements based on the findings. As with all recommendations, the City will consider the effect any recommendations may have on adjacent streets to ensure the unintended consequence of shifting the problem elsewhere is avoided.