Throughout Bloomington, residents have become increasingly aware and concerned about the negative impact speeding vehicles have on their quality of life. They view speeding vehicles, cut-through traffic and associated noise and litter as detrimental to their security, property values, and the livability many have worked so hard to achieve.
City staff members from Public Works, Police, and Administration work with residents to find potential answers. At times, the answer has been "traffic calming." This is a traffic engineering technique to reduce speeds and includes such items as installation of speed humps. However, the use of traffic calming devices is used only rarely under a defined set of circumstances.
"Traffic calming is the combination of mainly physical measures that reduce the negative effects of motor vehicle use, alter driver behavior and improve conditions for non-motorized street users." (Institute of Transportation Engineers)
Traffic calming improvements typically incorporate any combination of the following features:
- Changes in horizontal and/or vertical alignment of the roadway.
- Roadway or lane narrowing.
- Changes of roadway surface texture or color.
- Aesthetic improvements using landscape materials for enhanced streetscapes.
Goals and Objectives
The goals of traffic calming are to:
- Improve the quality of life within neighborhoods.
- Increase safety and convenience for pedestrians and bicyclists, as long as such changes do not interfere with the safe operation of intended users of the roadways.
- Create attractive streetscapes.
- Reduce negative effects of automobile travel.
- Reduce the number and severity of automobile collisions.
Specific objectives of traffic calming include:
- Reduction in the speed of motor vehicle traffic on residential areas to below a 15 percent violation rate (VR).
- Reduction in the volume of traffic traveling through residential areas.
- Causing unnecessary cut-through traffic to instead use streets designated as collector or arterial streets.
- Promote other modes of travel (walking, cycling, mass transit).
Traffic Control Procedure
City staff members have examined many different calming techniques. They recognize that Bloomington's neighborhoods are all unique and require a variety of traffic calming techniques to address differing traffic conditions. Regardless of the type of traffic calming device sought, a uniform procedure is set for requesting, evaluating, designing, authorizing, and building traffic control devices on Bloomington streets. That procedure is set forth below.
Submitting Requests and Complaints
Requests for traffic evaluation and traffic related complaints may be initiated by individual citizens, neighborhood associations, City government officials, or other groups. Requests for traffic evaluations or complaints of chronic speeding, cut-through traffic, parking, signage, or other traffic-related problems occurring on Bloomington streets should be submitted in writing to the City of Bloomington Public Works Engineering Division using the City's form. The City Engineer exercises discretion in resolving requests and complaints and forwards unresolved issues to a staff committee.
Working as a committee, city staff members review each request or complaint to determine the appropriate response. Some complaints may not rise to a level warranting remedial action. In such cases the complaining party will be notified and advised that the issue may be resubmitted in one year for further consideration. Significant traffic issues may be resolved through increased enforcement efforts, traffic control improvements, traffic calming improvements, or a combination thereof. The person or group making the original request or complaint will be notified in writing of the action the City intends to take regarding the request. Requests for traffic calming improvements will proceed to the evaluation phase to determine if all qualifying criteria are met. Locations which clearly do not meet traffic calming criteria will be reviewed by staff for speed enforcement or other traffic engineering solutions.
Traffic Calming Criteria
Traffic calming criteria have been established by the City Administration and may be revised from time to time by City Administration.
Streets that (usually) do not qualify for calming
Physical traffic calming improvements will not be considered for any street if any of the following conditions exist:
- If the street is identified as a "collector" or "arterial" street on the BLOOMINGTON-NORMAL STREET AND HIGHWAY PLAN.
- If the average traffic volume is greater than 2,000 vehicles/day (ADT).
- If the average traffic volume is less than 900 vehicles/day (ADT).
- If the average violation rate (VR) of the statutory or posted speed limit is less than or equal to 25 percent.
- If the 85th Percentile speed for the study segment is less than 5 MPH over the posted or statutory speed limit.
- If building lots in the study area are not built out to at least 90 percent of available lots.
** Note: Any of the above defined conditions can be waived by a reviewing group of staff members, and waivers will be included in documentation.
Evaluation of Traffic Conditions
Traffic calming requests which pass preliminary review will proceed to the evaluation phase. If not already collected, relevant traffic data is collected during the evaluation phase. When the data reveals that traffic calming criteria have been met, the appropriate type of traffic calming technique is determined by City staff. If the criteria are not met, these locations may be reevaluated upon request one year following the date of the data collection upon which the most recent request or complaint was rejected for traffic calming.
The evaluation phase involves the collection of data including street classification, volume, speed, traffic crash history, and other relevant information. This information gets collected and evaluated by the Engineering Division of Public Works Department. Engineering recommends a specific traffic calming device, and a staff committee reviews the findings.
If significant traffic diversion is anticipated, the staff prepares a diversion analysis. Based upon the diversion analysis, if staff committee determines that the proposed traffic calming improvements are expected to create equal or greater traffic problems on another residential street the traffic calming device(s) will not be installed. In instances in which significant diversion is not an issue, the proposed traffic calming design will be used as the basis for the traffic calming ballot.
The City will host a public meeting to discuss the proposed traffic calming design for the area under study. Other residents and business owners in areas adjacent to the study area may also be specifically invited. However, voting on the proposal is limited.
Traffic Calming Vote
A supermajority of affected property owners is required for traffic calming installation to proceed.
Ballots only go to property owners whose lots are contiguous to the street segment(s) upon which traffic calming devices are proposed to be installed and property owners whose lots lie on an intersecting street and who would have to pass over the traffic calming devices to access their property. In order to assess support for the installation of the proposed traffic calming improvements, a mailed ballot system is used.
Passage of a traffic calming initiative requires at least 70% of the returned traffic calming ballots be marked in support of the initiative. To be counted, mailed ballots must be returned within 14 days of the postmarked mailing date.
When a traffic calming initiative passes, the construction phase begins. Engineering staff in the Public Works Department will finalize the design approved by the eligible voters, and add the project to the list of existing traffic calming projects Construction of traffic calming improvements will ordinarily be done in the order they are approved, absent extenuating circumstances.
The number of traffic calming projects installed each year depends on the availability of City resources. Projects will be ranked in the spring of the year, and neighborhood associations will then be informed in writing by the City of their project's ranking and given an opportunity to comment. Based on these comments, a priority ranking list will be presented to the City Manager for final approval.
Device Maintenance and Replacement
Traffic calming devices such as speed humps and traffic circles, like any other part of the road require maintenance and eventual replacement. The City has been installing and maintaining traffic calming devices since 1998. Time has shown that some traffic calming devices are easier and more cost effective to install and maintain. Some types of traffic calming devices remain effective as a traffic calming tool while other types deteriorate, become an eye sore, and in general lose their ability to command respect and be an effective traffic calming device.
The City has determined the hot mix asphalt speed hump to be the most durable, low cost and low maintenance of the traffic calming devices installed since the beginning of the City’s traffic calming program. The humps last as long as the wearing surface of the street they are on and have been easily replaced when the streets are resurfaced. For this reason, the City of Bloomington reserves the right to replace other types of traffic calming devices with a speed hump when that device has completed its useful life or needs to be removed as a part of another project or for utility maintenance.
Changing to a different type of Traffic Calming Device shall require the following:
- A written recommendation for a change in device type from the City Engineer to a staff committee reviewing the situation.
- Written notice to affected residents living within, at most, 350 feet of the calming device in question. Staff will consider written responses from residents prior to making a final decision.
- A recommended change from the staff committee.
Device Removal Process
Traffic calming improvements may be removed from a street segment through a successful neighborhood petition. To be successful, this process requires approval of at least 90% of property owners of lots whose owners were eligible to vote on the original traffic calming initiative. The removal process may not be started until the improvements have been in place for at least a one year (365 day) period.
The availability, structure, and operation of the Selective Traffic Enforcement Program (STEP) will be governed by Bloomington Police Department Policy.