Programs That Work A Procedure for Improving the Accuracy of Visitor Counts at State Parks

Visitation counts are the measures most widely used by park managers to demonstrate accountability and good stewardship of the public resources that legislatures invest in parks. Ostensibly, counting visitors may appear to be a simple task, but experienced park managers are aware that it is a complicated and difficult challenge with three dimensions: human, logistical, and technical. Part of the challenge has a human dimension in that pressure to demonstrate accountability may tempt managers to inflate visitation counts. However, much of the challenge is logistical and technical. The logistical dimension relates to the placement and maintenance of traffic axle counters, while the technical dimension refers to transposing axle counts into visitor numbers. In addition to providing an overview of the roles of the three dimensions, this paper describes a procedure implemented in Texas State Parks for addressing the technical dimension. To transpose raw axle count numbers into visitation estimates, two parameters have to be calculated: (i) the proportion of axles attributable to visitors, as opposed to officials, vendors, or visitors re-entering the park on the same day (parameter A); and (ii) the average number of visitors per axle (parameter B). A study was conducted for a 12-month period in 92 Texas state parks, during which time observers recorded the data relating to parameters A and B. As a result of the study, these empirically derived parameters could be used by each park site to transpose its axle counts to visitation estimates. Two major findings emerged from the study. First, the parameter estimates varied widely among the 92 parks, whereas the Texas Parks and Wildlife Department (TPWD) traditionally had used a single value systemwide for each parameter. The range for parameter A was 29% to 99%, while for parameter B the values ranged from 0.65 to 2.60. Second, the empirical values were substantially lower than those which traditionally had been used by the agency. Empirical verification of the parameter values used in visitor estimation formulas can improve the accuracy of patron counts and subsequently increase an agency’s credibility in the eyes of legislators.