Chapter 10.20
TRAFFIC CALMING
Sections:
10.20.060 Speed hump request procedures.
10.20.070 Funding for speed humps.
10.20.080 Installation of speed humps.
10.20.090 Evaluation, modification, and removal.
10.20.010 Title.
This chapter shall be known as the “neighborhood traffic calming procedure” for the city of St. Helens. (Ord. 3300 § 2 (Att. A), 2024)
10.20.020 Purpose.
The purpose of traffic calming is to outline the policy and procedures for guiding the process of evaluating the feasibility of installing traffic calming measures on city streets through the use of devices and techniques that reduce traffic volume and speed in neighborhoods while maintaining maximum mobility and access. Traffic calming attempts to make drivers aware of the fact that they are sharing the space of a street with other users. The traffic calming ordinance provides a procedure to consider, evaluate, implement, and remove traffic calming measures on streets in the city of St. Helens. (Ord. 3300 § 2 (Att. A), 2024)
10.20.030 Policy.
(1) To enhance the quality of life and the safety of the city’s residents, the city of St. Helens is establishing this traffic calming policy. It is the policy of the city of St. Helens that motor vehicles traveling in excess of posted speed limits present a threat to public safety and should be first addressed using the least intrusive methods available that will be effective for a given situation. Enforcement is the preferred method of abatement. Where the necessary level of enforcement is unattainable, engineered measures may be considered. The goals of this program are:
(a) Reduction of traffic speed to a safe and appropriate limit.
(b) Encourage community participation.
(c) Encouragement and enhancement of vehicle, pedestrian, and bicycle systems.
(d) Limiting traffic calming to local residential streets.
(e) Ensuring emergency vehicle access.
(f) Use of effective, efficient, economical, and environmentally sound traffic calming solutions.
(g) Multidiscipline input from engineers, planners, police, and fire. (Ord. 3300 § 2 (Att. A), 2024)
10.20.040 Definitions.
(1) The following words, terms, and phrases, as used in this chapter, shall have the meanings respectively ascribed to them in this section, unless the context clearly indicates otherwise:
(a) “85th percentile speed” means the speed, in miles per hour, at or below which 85 percent of the drivers travel on a road segment. Motorists traveling above the 85th percentile speed are considered to be exceeding the safe and reasonable speed for road and traffic conditions.
(b) “Average daily traffic” (“ADT”) means the volume of traffic passing a point or segment of a road in both directions, during a period of time, divided by the number of days in the period and factored to represent an estimate of traffic volume for an average day of the year.
(c) “Collector” is the street functional classification for streets which provide access and mobility within neighborhoods, and commercial and industrial areas. Collectors gather traffic from local streets and serve as connectors to arterial streets.
(d) “Local (residential)” is the street functional classification for streets which provide access to residential and other properties within neighborhoods and are not considered thoroughfares or serve major traffic generators.
(e) “Major arterial” is the street functional classification for streets which carry the highest volumes of through traffic, provide mobility within the community, and provide continuity for intercity traffic through the urban area.
(f) “Minor arterial” is the street functional classification for streets which interconnect and augment the major arterial system and accommodate intracity and intercity trips. Minor arterials provide connections between residential, shopping, employment, and recreational activities within the community.
(g) “Speed hump” means a rounded raised area built across a road as a traffic calming measure intended to slow traffic speeds on low volume, low speed roads.
(h) “Street functional classification” is a street’s operational and design characteristics such as pavement width, right-of-way requirements, driveway access spacing requirements, and appropriate type of pedestrian and bicycle facilities. Functional classification of streets is determined by the city of St. Helens transportation system master plan.
(i) “Traffic calming” is the deliberate slowing of traffic on a street by installing speed humps or other obstructions referred to as “traffic calming devices.”
(j) “Traffic calming device” means an element of a traffic calming plan selected from among those devices authorized herein for use within the city.
(k) “Traffic calming study” means an appraisal of traffic conditions in the development of a plan for installing one or more traffic calming devices on a city street. (Ord. 3300 § 2 (Att. A), 2024)
10.20.050 Speed humps.
(1) For the purposes of the traffic calming program, speed humps as a traffic calming measure may be warranted if the following conditions are met:
(a) Street Classification.
(i) Street shall be classified as a local (residential) street in the current city of St. Helens transportation system master plan. Speed humps shall not be considered for use on collector, major arterial, or minor arterial streets because of its potentially severe safety consequences on traffic, emergency services, and other service delivery activities.
(ii) The local (residential) street is not a primary access route for emergency vehicles, a truck route, or a route that is heavily used due to the proximity of an emergency vehicle facility.
(b) Traffic Investigation.
(i) The 85th percentile speed must be at least five miles per hour over the posted speed limit.
(ii) More than 50 percent of the vehicles traveling on the street must be documented to be traveling at or above the posted speed limit.
(iii) Street must have a posted speed limit of 30 miles per hour or less.
(iv) The average daily traffic (ADT) volume must be at least 500 vehicles per day and a maximum of 2,500 vehicles per day.
(c) Street Geometry.
(i) Speed hump will not result in the need for widening other roadways, for additional storm drain measures, cause delays in emergency response time, or cause drivers to seek other routes to bypass the traffic calming measure as determined by the public works department.
(ii) Street grade must be less than eight percent.
(iii) Street must have adequate sight distances to safely accommodate the speed hump as determined by the engineering division.
(iv) Street must have no more than one travel lane in each direction.
(v) Street must be at least 1,000 feet in length, uninterrupted by stop signs, yield signs, or signal controls.
(vi) Speed hump shall not be installed on sharp curves or curves exceeding a horizonal curve radius of 300 feet.
(vii) Speed hump will not be installed closer than 200 feet from an unsignalized intersection and 250 feet from a signalized intersection.
(viii) Speed hump shall not impede access to driveways.
(ix) Speed hump shall not be installed on cul-de-sacs or no-outlet streets less than 1,000 feet in length.
(x) Speed hump shall not be installed within 10 feet of a fire hydrant.
(xi) Speed hump shall not be installed over manholes, water valves, or street monumentation. (Ord. 3300 § 2 (Att. A), 2024)
10.20.060 Speed hump request procedures.
(1) A person(s) interested in pursuing the installation of a speed hump on a street shall submit a speed hump request to the public works engineering division with the appropriate fees. Fees associated with all traffic calming requests shall be set by resolution of the city council.
(2) Engineering division staff will make a preliminary assessment to determine if the requested location is on an eligible road. If the location is on an eligible road, engineering division staff will determine an appropriate target area to circulate a neighborhood speed hump support petition. The target area will be determined based upon the density of the lots and the roadway use.
(3) Applicant shall circulate a neighborhood speed hump support petition in the area determined by the engineering division and shall provide documented evidence of community support for the installation of speed humps. Petition must document a minimum of 75 percent of the properties within the boundary area in support of the installation of traffic calming measures.
(4) After the applicant provides required community support for speed humps as required, engineering division staff shall conduct a traffic study to determine if the street meets the requirements for speed humps based on the criteria set forth in SHMC 10.20.050. Speed study shall be conducted for a minimum of 30 days.
(5) If the street meets all criteria for speed humps, additional approval of the following agencies in support of the speed humps is required, including the public works department, planning department, police department, and fire department.
(6) After the community engagement process has been completed, residential approval thresholds are met, and traffic calming funds have been received by the city, the engineering division shall complete a full engineering study of the site and develop a preliminary design proposal for the requested speed hump.
(7) A public hearing shall be held prior to installation of speed humps to present the preliminary design to interested residents. (Ord. 3300 § 2 (Att. A), 2024)
10.20.070 Funding for speed humps.
(1) A street which qualifies for speed humps may be funded by the city, when such funds become available, by an individual, or by a group of individuals.
(2) The individual or group of individuals funding speed humps must enter into a memorandum of understanding (MOU) with the city of St. Helens, wherein they agree to pay for all costs associated with the installation of speed humps on the street, including design, permits, construction, inspection, and administrative fees.
(3) After an MOU is executed, payment shall be made to the city of St. Helens.
(4) Payment for speed humps does not relieve applicant from the requirement of obtaining 75 percent community support in favor of the installation of traffic calming measures, or from any other criterion set forth in this chapter. (Ord. 3300 § 2 (Att. A), 2024)
10.20.080 Installation of speed humps.
(1) The installation of speed humps shall be scheduled by the public works department upon approval by the city council and receipt of funds for the work.
(2) Completion of the installation of speed humps shall be subject to work crew schedules, purchasing constraints, and appropriate weather conditions. (Ord. 3300 § 2 (Att. A), 2024)
10.20.090 Evaluation, modification, and removal.
(1) Engineering division staff shall evaluate speed humps and other traffic calming measures six months after installation. Traffic data shall be collected and compared to the previously collected “before” data. The comparison will evaluate the measures to determine if corrective measures or other actions are needed.
(2) With the approval of city council, speed humps may be removed or altered at any time for the following reasons:
(a) Emergency response is significantly impacted.
(b) Traffic count for the street exceeds 2,500 vehicles per day.
(c) The city’s public works director determines that it is in the best interest of public safety.
(3) Residents within the traffic calming area may request removal of the speed humps only after the measures have been in place for two years by submitting a petition to the city. The petition shall request removal of the speed humps, acknowledge that the residents shall pay for the removal, and include the signatures of at least 75 percent of the property owners within the calming area. Upon receipt of the petition, the city will assess the property owners within the traffic calming area for the costs and then remove the speed humps. (Ord. 3300 § 2 (Att. A), 2024)