69-73 WEB MAY-Knapp

69 INTRODUCTION It has been estimated that more than 1 million deer-vehicle crashes (DVCs) occur each year in the United States, costing the traveling public more than $1 billion.1 Some of the countermeasures that have been applied to reduce DVCs include deer fencing, wildlife crossing structures, roadside reflectors, vehicle whistles, highway lighting and speed limit reductions.2–4 The installation of deer crossing warning signs (W11-3) is the most widely used attempt at DVC mitigation (see Figure 1). The general objective of W11-3 signs is to warn drivers of a deer crossing danger and, it is hoped, produce an appropriate reaction (such as increased focus and/or speed reduction). The actual effect of these signs on driver behavior is not the focus of this feature, but it may be related to the approach currently used to install them. This feature describes the current status of W11-3 sign installation guidance and suggests the inclusion of DVC data comparisons for a more quantitative installation approach. The suggested comparisons range from the general (statewide) to the specific (roadway segment) and were applied at 22 existing W11-3 sign pair locations. The results of this application are described. In addition, a series of roadway and roadside characteristics correlated with DVC problem locations is discussed. This information should be useful during the installation of W11-3 signs. The overall objective of the suggested comparisons is to limit the installation of W11-3 signs to locations with greater than typical existing or expected DVC safety problems. This approach should maximize the impact, if any, of W11-3 signs on driver behavior. CURRENT INSTALLATION GUIDANCE AND PRACTICE The overuse and/or misuse of any warning sign generally reduces its credibility, impact and usefulness. The Manual on Uniform Traffic Control Devices (MUTCD) avoids these types of outcomes by providing warning sign installation standards, guidance, options and support. Section 2C.41 of the 2003 Edition of MUTCD includes language that applies to the installation of W11-3 signs that is primarily qualitative in nature.5 MUTCD indicates that W11-3 signs may be placed where “...unexpected entries in the roadway...might occur.” A support statement also recognizes that unexpected deer-vehicle conflicts can be “...relatively confined, or might occur randomly over a segment of roadway.”6 Purposely broad in its treatment of W11-3 signs, MUTCD does not suggest any type of data-focused installation criteria. The creation and application of a W11-3 installation approach based on crash data is the responsibility of the individual jurisdiction.