STAFF REPORT
Operations Committee,
August 2, 2006
Dynamic Message Signs (EN07-014)
Consideration of recommendations to improve the
aesthetics of the dynamic message signs
Speaker: Steve Brown
From: Tim
Bailey, P.E., Director of Engineering
Prepared by: Dale W. Privette, P.E., Senior Engineer
Approved by: William B. Coleman, Jr., Town Manager
Approved by: Benjamin T. Shivar, Assistant Town Manager
Over the past few weeks, Council members and staff have been receiving feedback from citizens concerning the appearance and questioning the value of the newly installed Dynamic Message Signs (DMS). Staff has had opportunities to review these issues and now proposes recommendations to address citizen concerns.
In April 2000, Town Council approved a recommendation to proceed with a feasibility study for the Cary Signal System. In March 2001, the Operations Committee was presented with the consulting engineer’s functional requirements for the recommended system. Of these functional requirements, the Town’s engineer recommended the installation of ten DMS with a system expandable to thirty DMS. Town Council approved the recommendations of the feasibility study in the same month, and a design consulting engineer was also selected at that time to design the recommended system. In July and August 2002, the Town’s design engineer and staff worked with the Information Services Advisory Board (ISAB) and Council to gain concurrence on the traveler information components of the system including the DMS. That August, Council concurred with the staff’s recommendation to include the DMS, along with other means of conveying traveler information, such as public TV and internet applications, in the scope of the project. The design firm completed the plans in March 2003, and a contractor was hired in the same month to begin construction of the system.
Early in the construction process, the contractor provided material submittals for the materials and vendors they proposed to use in constructing the system. Since all but one of the DMS would be located within the North Carolina Department of Transportation’s (NCDOT) right of way, NCDOT played a major role in reviewing and approving the submittals and ensuring that the signs would be built in accordance with NCDOT’s rigid specifications and national standards. With regard to the appearance of the signs, staff investigated options of scale with the sign vendor and chose a mixture of flat-topped signs and “A” frame signs similar to examples found in other U.S. cities. NCDOT required that each sign face have a black matte anodized finish and a lexan cover. They required that the LED pixels only display characters in the “highway yellow” color. NCDOT approved signs that would display a maximum of 15 characters per line, and 3 lines of 8-inch height characters.
The designers and staff spent considerable time reviewing mounting options (overhead on full structures, overhead on cantilever structures, dual pole mounted, single pole mounted, decorative pole mounted) and determined that single pole mounting was the most cost effective option. The location of each DMS was first determined by recommendations in the feasibility study. During the late design and early construction processes, however, it was determined that some of the DMS would need to be relocated due to underground and overhead utility conflicts, lack of available right of way, and proximity to private residences. Some signs were relocated further away from the core of Cary to provide motorists with more options for alternate route selection decisions. One of the primary goals of the system was to provide timely, regional information to motorists, and these decisions served both goals.
The contractor began installing the DMS in November 2005. Staff instructed the contractor to install the DMS on Chapel Hill Road near Trinity Road first and then wait for a three-week period so the public would have an opportunity to provide feedback. Our Public Information Office prepared a news release about this first sign to further enlist feedback. Finally, staff gave the contractor the go-ahead to install the remaining DMS after no comments were received. The first sign received power service in June 2006. All but one of the 9 currently installed DMS are located at entry points to the Town (two signs on NC55, two on Davis Drive, two on Chapel Hill Road, one on Holly Springs Road, and one on North Harrison Avenue). One sign is located on Kildaire Farm Road near High Meadow Drive. Two other DMS will be installed soon, once issues with adjacent development plans are resolved (Kildaire Farm Road near Arthur Pierce Road and Carpenter Fire Station Road near Green Level to Durham Road). The final DMS will be installed by NCDOT’s contractor for the US1/64 widening project currently under construction. Of the nine DMS currently installed, six now have power service and the other three should have service within the next month. Staff begins the testing period for each sign once it has power and has been commissioned in the field.
The purpose of the DMS is to provide motorists with real-time traveler information that includes location, conditions, and suggested driver action. The quality of traffic-related messages as well as the overall presence of DMS affects public perception. Cary’s traffic management operators understand that DMS affect public perception even when they are not actively conveying traffic-related information. Motorists may perceive blank signs as inoperable or may question the allocation of resources to technologies that seem to be (from their perspective) underutilized. On the other hand, displaying information not germane to real-time traffic conditions may erode the credibility of DMS and reduce their effectiveness as a traffic management tool. Incidents that typically are benefited from the use of a DMS include lane closures, road closures, evacuations, unexpected conditions, expected travel times, and special event traffic. Messages regarding public health and safety may be displayed for specific cases. The Town’s engineering and police departments, as well as NCDOT operators, will have the ability to remotely post messages on the DMS. This is essential to provide regional, real-time information. Should a wreck occur on I-40 in RTP during the afternoon rush hour, for example, and motorists decide to exit onto NC54 (Chapel Hill Road) as a parallel alternate route, NCDOT operators will be able to post messages on the their I-40 DMS and Cary’s Chapel Hill Road DMS to advise motorists of the unexpected conditions. Should a child be abducted in the region, the state authorities would likely issue an AMBER alert providing specific details that would be posted on the DMS in an attempt to identify and capture the suspect(s). Messages will only be displayed that are accurate, timely, and meaningful.
As the DMS have started displaying test messages, staff has begun to receive feedback from citizens regarding the appearance of some of the DMS. The sign installations consist of the black fronts and silver backs and sides with single metal support poles and silver equipment cabinets. Most of the signs have been installed in close proximity to existing trees, bushes, and other vegetation that helps soften the appearance of the signs for motorists approaching the back side of the sign. Some signs, however, do not have vegetation nearby and therefore catch the eye of motorists more readily.
Staff has frequently discussed these issues, researched DMS installations in other parts of the country, and now offers the following options to address aesthetics concerns that have been raised:
Fiscal Impact: Fiscal impacts could vary greatly depending on which option(s) Council chooses to pursue. Since 11 of the 12 signs are ground mounted, estimated costs are based on 11 signs only:
Maintenance of the signs would become more costly with any of these options, with the landscaping option requiring the most intense ongoing maintenance. Painting options would require annual re-painting activities. Replacement with a new structure would require the least amount of annual maintenance.
Staff Recommendation: Staff recommends that each DMS, DMS pole, and equipment cabinet be painted hunter green and landscaping be installed around the base of the installations to address aesthetic concerns. Sample photos and renderings of this recommendation for the DMS on Kildaire Farm Road are attached below to demonstrate what the signs might look like after painting and landscaping.
Front of sign – current
Front of sign – painted, with additional landscaping
Back of sign – current
Back of sign – painted, with additional landscaping