Selection of Performance Measures for a State Access Management Program

In 2007 Virginia’s General Assembly authorized the state Department of Transportation (VDOT) to develop regulations governing access to the state highway network. While the potential benefits of access management are well known, realization of these benefits is not guaranteed. Consequently, this paper describes a methodology to identify and select performance measures to evaluate a state’s access management program. Application of the methodology yields 50 potential performance measures, of which 5 are recommended for implementation based on a survey of end users, data collection feasibility, and the likelihood of the measure improving as access management initiatives continue. The five performance measures are summarized as: crash rates, percentage of signals meeting spacing standards, percentage of commercial entrance permits meeting spacing standards, percentage of median openings with left turn lanes, and percentage of localities with a corridor access management plan. The results demonstrate that no single performance measure will by itself be sufficient, but that multiple measures are needed in three discrete areas: administration (e.g., the mechanism through which permits are granted), design (e.g., geometry of highway access), and outcomes (e.g., crash rates). In contrast to some literature that supports outcome-based performance measures, survey respondents expressed interest in non-outcome based measures, such as developing access agreements and corridor planning efforts. Implementing agencies prefer metrics that directly impact access management performance (e.g., percentage of signals meeting standards) in contrast to outcome measures affected by other factors (e.g., level of service). For agencies seeking to adopt these measures, the extent to which local considerations are a factor in performance measure selection is documented and alternative metrics are provided for states where local conditions may differ.