Road Safety Audits (RSA)

APPENDIX A
RSA CASE STUDIES

RSA NUMBER 8

CITY OF TUCSON (ARIZONA):
RSA OF PEDESTRIAN CROSSING IMPROVEMENTS

PROJECT BACKGROUND:

HAWK (High-Intensity Activated CrossWalK) signals are a type of traffic control beacon for marked pedestrian crosswalks, developed by the City of Tucson and implemented in Tucson and elsewhere in Arizona.  The City of Tucson received approval from FHWA to experiment with this device; it is not yet adopted in the Manual of Uniform Traffic Control Devices.  The innovative HAWK signal, shown in FIGURE A.12, incorporates elements from fire station signals and school bus flashing displays, as well as from European pedestrian signal displays, to provide a familiar signal sequence for drivers and pedestrians.  The HAWK signal is activated by a pedestrian pushbutton.  The activated signal progresses from a dark display through flashing amber, solid amber, solid red, and flashing red, ending with a dark display.  Drivers are required to stop during the solid red display, and may proceed with caution during the flashing red display.  Pedestrians are controlled using traditional pedestrian signal displays and, at the sites audited under this contract, countdown timers.

At the time of the RSA, about 40 HAWK signals were operating in Tucson, and the City was expanding its HAWK installation program.  In 2003, the City’s Mayor and Council allocated increased funding to install HAWK signals at six additional locations throughout the City.⁴ The six sites selected for HAWK implementation were chosen on the basis of pedestrian and bicycle collision frequency from 1999 through 2002.  The six sites, listed in TABLE A.9, were the focus of this RSA. 

* Annual Average Daily Traffic volumes reported by the Pima Association of Governments

At the time of the RSA, the contract for construction had been awarded, and the underground portion of construction was underway or had been completed at many of the sites.  Final design drawings for the signal hardware were complete.  This RSA of locations where an experimental pedestrian signal system was being implemented provided an opportunity to conduct an RSA with a focus on pedestrian needs.

KEY RSA FINDINGS AND SUGGESTIONS:

The RSA findings were divided into two categories:

• general HAWK system issues and suggestions (Issues 1 and 2),
• site-specific issues and suggestions (Issues 3 to 6).

Observations regarding the general HAWK system (Issues 1 and 2) include suggestions that are intended to enhance the HAWK system with a view to national adoption as a useful and effective traffic control device with an intermediate level of control between a traditional flashing amber beacon and a full signal.

In its response, the City undertook to consider the RSA team’s suggestions and to monitor a number of locations at which safety issues had been identified.  For this late-stage RSA, suggestions were declined where they would entail substantial changes to completed works, such as changes to signal equipment or completed electrical works.

KEY LESSONS LEARNED:

The RSA process can enhance the implementation of innovative road safety measures with the aim of promoting their success.   This RSA focused on pedestrian crossing locations where the HAWK device was to be installed.  One of the outcomes of the RSA has been a set of suggestions to enhance the HAWK system with a view to its wider (statewide or nationwide) application.  In this way, the RSA may have been beneficial as a means of reviewing the HAWK signal in a working environment, identifying possible factors that may compromise its successful implementation elsewhere, and suggesting measures to address them.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.

²Eugene Wilson and Martin Lipinski. NCHRP Synthesis 336: Road Safety Audits, A Synthesis of Highway Practice (National Cooperative Highway Research Program, TRB, 2004)