User:Hoskir/Revision Request 4250
COPY 902.2.5
902.2.5 Basis of Removal of Traffic Control Signals (MUTCD Section 4B.05)
Support. There are locations where, due to changes in the traffic conditions, the need for a traffic signal is no longer present. Several obvious locations would be where a school or commercial development has a signal at an entrance, and the facility has closed or relocated. It is also possible traffic signals at intersections of public streets can no longer be justified due to changes in traffic patterns, such as new roadway construction or changes in the neighborhood. In any case, it can be a very difficult decision to remove an existing signal.
If the removal of an existing traffic signal is to be successful, misperceptions by the general public are among the greatest hurdles to overcome. While these can be very high hurdles, they are possible to clear if the proper engineering considerations are made and supported.
The removal of an unwarranted signal can result in cost savings to the public, that includes: reduced delays, reduced energy and fuel consumption and reduced emissions. Quantifying the annual savings to the public might help with the removal of the signal.
Guidance. There are four major considerations that should be reviewed before the removal of an existing signal: warrants, crash experience, sight distance and pedestrians.
- A. Warrants. If traffic volumes are so that the highest activity day is only 50 percent of the required volumes to meet any of the MUTCD warrants, then removal can be considered. For example, Warrant 1 requires 150 side street vehicles per hour for any eight hours of an average day to be considered warranted. If there are 75 or fewer this would not be considered a warranted hour. If none of the hours of a normal day meet this level, then the signal could be a candidate for removal. Care must be taken when evaluating the main-line volumes because if they are at or are significantly higher than the warrant requirements, removal could be more difficult.
- B. Crash Experience. Crash experience, both historical and expected, can be a very tough issue when considering a signal for removal. A thorough review of the crash history at the intersection is to be done to determine what has been occurring at the intersection. Historically, the removal of an unwarranted signal can cause a 90 percent decrease in rearend type collisions, a 30 percent increase in right angle crashes, 10 percent increase in left turn crashes, and 10 percent increase in pedestrian crashes.
- The nature of the crashes that could be expected after the removal of the signal is influenced by the type of control that will replace the signal. If a multi-way stop is used then, in general, an increase in crashes would not be expected. If, however, a two-way stop control is planned then the percentage changes described above can be expected.
- Regardless of the traffic control that is planned after the signal is removed, a detailed before/after review is to be documented.
- C. Sight Distance. The sight distance available to the side street, particularly if two-way stop control is proposed, is very important to the removal decision. If the sight distance available for the side street is less than the stopping sight distance for the mainline approach speed, signal removal should not be considered without providing for the recommended sight distance.
- D. Pedestrians. Consideration for pedestrians using the existing signal must be made using appropriate warrants. If a signal is removed, alternate pedestrian accommodations should be considered.
Standard. After all of the above considerations have been evaluated and if the decision is made to proceed with the removal, the following steps shall be taken:
- Determine the appropriate traffic control to be used after the removal of the signal.
- Central Office Highway Safety and Traffic Division shall be advised and documentation of the above noted evaluations provided to support the decision.
- Public notice of the intention to remove shall be made. This can consist of news releases, public hearings and presentations at city council meetings or canvassing parties affected by the removal. The district must be prepared to answer any questions that might arise.
- Establish a date for the signal to be turned off and notify Central Office Highway Safety and Traffic Division.
- After the notification period has been successfully completed, the physical removal of the signals can be initiated. A comprehensive removal shall be completed with all concrete foundations and bases removed to at least flush with the ground, when applicable. Consideration shall be given to filling in or securing any pull boxes. Install the appropriate STOP sign control or other traffic control devices as necessary.
Guidance. Changeable message signs (CMS) should be in place a minimum of two weeks prior to the signal removal with the message displaying the removal and date. Additional CMS information can be found in EPG 903.12.
Option. During the notification period, flashing or covering the signal heads may be used in combination with CMS for a length of time and flash type determined at the District’s discretion.
Instead of total removal of a traffic control signal, the poles, controller cabinet, and cables may remain in place after removal of the signal heads for continued analysis.