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Publication Number:  FHWA-HRT-17-077    Date:  November 2017
Publication Number: FHWA-HRT-17-077
Date: November 2017


Safety Evaluation of Red-Light Indicator Lights (RLILs) At Intersections

Appendix. Additional Installation Details

This appendix presents additional details provided by FDOT and local agencies about the use of this strategy. The information presented here may be of use to other agencies interested in using this strategy. Participants were asked to provide responses to six questions. The following section provides the questions and responses.

  1. Were there any notable variations in level of enforcement from location to location by district or any variations in driver awareness campaigns? Was the driving public made aware of what the indicator lights are and how they are used (e.g., supplemental warning and regulatory signs)?

District 1 provided the most feedback to this question, indicating that some level of awareness campaign was used. The Bartow Police Department noted that it participated in some awareness programs in conjunction with the Polk County Community Traffic Safety Team during the initial installation. However, after installation, the department did not participate in any awareness programs other than enforcement of the lights. Since installation, the Bartow Police Department noted that it has used the lights for the purposes of red-light violators, and they have been beneficial to the department’s enforcement efforts. The department began using the lights immediately after installation and has continued using them.

The Charlotte County Sheriff’s Office (CCSO) noted that the white strobe lights were a very useful tool that helped with enforcement efforts, but since installation, CCSO has not increased its time of duration at those specific intersections. The CCSO increases its red-light enforcement or duration at intersections based on traffic crash statistics. The Collier County Sheriff’s Office noted that it used press releases when the indicators were first installed, using some minor coverage in print media. The Collier County Sheriff’s Office did not change levels of red-light enforcement or conduct special operations because of the indicator lights.

Highlands County indicated that it completed public awareness programs dealing with all topics involving traffic enforcement/education. However, the county did not single out red-light running. Most awareness programs focused on local news media or meetings held at different homeowners’ associations. The Lake Wales Police Department noted that a press release was issued when the lights were initially installed.

The Manatee County Sheriff’s Office indicated that it conducted red-light enforcement details three times per month, targeting 1 of the 10 most dangerous intersections based on crash statistics. The Sheriff’s Office also noted that the strobe installation made enforcement less manpower dependent. The Sheriff’s Office did not conduct any public awareness programs strictly targeting strobe enforcement; however, the office frequently had newspaper articles concerning red-light enforcement. The Naples Police Department distributed press releases on the indicator lights (e.g., an article printed in the local newspaper) and also talked about the lights on several talk radio shows on an AM station.

Districts 2 and 5 did not comment on any awareness campaigns or utilization of the indicators.

  1. The installation dates for the treatment sites on our list range from 2004 to 2010. What types of indicator lights (e.g., white incandescent) were installed at these treatment sites? Were the indicator lights located on the signal heads, mast arms, or other locations? If you have standard drawings or specifications that addresses these questions, please pass them along.

Orange County noted that the first bulbs were incandescent, 69-watt pedestrian bulbs; later they were “corncob” style 360-degree blue LED bulbs. Additionally, Orange County noted that some nearby agencies have mounted them to the mast arm, some have mounted them directly to the bottom of the green, and others have mounted the lights on top of the signal head.

Orange County has mounted them above the signal in every case. If a mast arm was used, a slip fit-threaded 1.5-inch PVC coupler was used to place the fixture on top of the signal brackets to secure it with a tapped screw. The globe would face up and be visible 360 degrees. If mounted on a span wire, agencies used typical pedestrian-style feet and tubes with the 90-degree elbows to turn them down. If the direction had an exclusive left and some standard ball indications, the confirmation lights were installed as far as possible from each other, left-most left-turn signal and right-most ball signal. In the area, conduit 90-degree elbows or a horizontal mounting installation to the pedestrian foot have been used. The pedestrian hardware increased the cost.

© Pelco Products, Inc.

Figure 11 provides an assembly sheet for the confirmation light with globe.

This technical drawing shows the parts and assembly of a confirmation light with a globe. The title block states that the manufacturer is Pelco Products, Inc. The drawing is labeled “Assembly Sheet” and the title of the drawing is “Confirmation Light w/ Globe, Alum, Pelco Number SM-0286.” The drawing shows an expanded version of the components that make up the confirmation light and how they fit together. The drawing is split into two major parts, labeled 1 and 2. Part 1 is the bracket that attaches the light to a fixture and is labeled “Part Number AB-01210L, Astro Mini-Brac, 1-1/2 inch NPS, Band Mount, Alum.” Part 2 includes the wiring and housing for the light fixture (the globe) and is labeled “Part Number SM-0284-XX, Confirmation light w/ Globe, Alum.” In the margins of the drawing is a taxonomy explaining what the letters and numbers in the part names stand for. The first six digits signify the part (confirmation light with globe), the next two digits indicate globe color, the next two digits indicate band length, the following two digits indicate an optional stainless-steel upgrade if applicable, and the final three digits indicate whether the part is “process no color” or “paint.” Below, a box lists different options for globe color and part number: clear (SM-0281-CL), blue (SM-0280-BL), red (SM-0295-RD), or no globe. A note about band length specifies that a 29-inch band fits a 4- to 8-inch diameter pole and a 42-inch band fits a 4-to 12-inch diameter pole. A stainless-steel upgrade is available, and the part number is AB-0303-SS. Wattage should not exceed 75 watts. The recommended bulb is a 67- or 69-watt 8000-hour traffic signal lamp.

© Pelco Products, Inc.

Figure 11 . Diagram. Assembly sheet for confirmation light with globe.

  1. Were there any other requirements (e.g., minimum or maximum traffic volume, presence of turn lanes, etc.) for the installation of indicator lights?

Red-light indicator lights were installed on both State highways and municipal streets. Locations were requested by city agencies, police, or pedestrian safety committees. FDOT provided the bulb holder/socket with the local signal agency providing cable and additional necessary hardware for mounting. FDOT approved the locations and provided the hardware as part of a safety initiative.

  1. Please describe any notable challenges related to the indicator light installation and how you overcame them.

A potential challenge is the presence of the indicator if the intersection goes to flash. The indicators are wired directly to the red bulb of the signal that they represent to simplify the wiring required. They flash with the signal indication, which means the intersection has red, yellow, white, and blue lights potentially if it goes to flash.

  1. Please describe any notable challenges related to the indicator light maintenance and how you overcame them.

No agencies reported maintaining the indicators; several noted that the operations costs were negligible.

  1. What lessons learned or recommendations would you share with another State interested in the widespread application of red-light indicator lights?

During the daytime, both the white and blue bulbs can be hard to see. At night, there was no visibility problem, the blue being distinctly noticeable. Agencies reported that RLILs mounted globe down/socket up seemed to make them slightly more visible because the sunlight might be more obscured (depending on the time of day), and the plastic globe lens seemed to last slightly longer. In addition, a broken lens would not allow the socket to get very wet, but a poor installation could allow it to fill with water.

The Florida two-point span wire gave agencies an attachment that typically made the light slightly obstructed from the front (drivers’ view), so all were mounted toward the back for the officer’s viewing. A box span wire design was very easy to plan, but a diagonal span intersection created problems due to use of two-way or greater assemblies and the ability to define the back of a signal. In addition, if the globe was mounted underneath the signal, the two-way (or greater) bracket might become impossible to install in a conventional fashion. Neighboring agencies installed additional hanger brackets adjacent to a two-way signal to indicate which signal they represented by associated physical location (i.e., left of the left signal and right of the right signal.) If the two-point style hanger were not used, as is common in Florida, one might be limited to use of the bottom of the signal. Being connected to the red means that the “special” indication on the bottom would operate in conjunction with the signal indication on the top.

One agency reported avoiding any five-section left-turns (unless part of a sequential side street movement) because of enforcement concerns; in addition, that agency avoided a two-way or greater signal combo because it was not clearly obvious what direction the supplement light indicated. The light has also been used on a blank-out no-turn-on-red symbol.

The public may inquire about what the lights mean. Even some police officers may not be aware of the purpose. (These officers are usually from an agency that has not been involved in the enforcement use in their jurisdiction.) Public awareness notification does not yet seem to exist in a user-friendly fashion.



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