Identifying community-level disparities in access to driver education and training: Toward a definition of driver training deserts

Obtaining a license may be challenging for teens due to access to driving instruction; in some states, behind-the-wheel (BTW) instruction is required to secure a license before age 18. We investigate spatial accessibility to BTW centers, and how this geographic distribution intersects with metrics of social disparity at the metropolitan level, toward identifying Driver Training Deserts (DTDs): geographic areas of disconnection to driver training. For the Columbus OH region, we collect socioeconomic variables at the Census tract unit of analysis and geocoded locations of public and private BTW training centers and estimate travel time to the nearest BTW training center. We define travel time as either the mean or the maximum travel time to BTW centers across all 1 km × 1 km grid cells within a Census tract. We employ spatial statistical approaches, including homogeneous/inhomogeneous K functions, to determine whether BTW training centers are clustered. Next, we define DTDs as Census tracts with a poverty rate and travel time to BTW centers larger than the 75th percentile values across the region. BTW training centers are spatially clustered across the region; the magnitude of this clustering is so great that BTW centers exhibit statistically significant patterns of clustering, even when considering the underlying spatial distribution of socio-economic characteristics. We find that 11–27 Census tracts are identified as DTDs depending on the definition of travel time. DTDs contain a disproportionate percent of the high poverty population (8.7–23.5%) and, depending on the definition of travel time, a disproportionately large African American population. Methodologically, defining DTDs necessitates a fine-grained spatial approach as suburban and rural Census tracts tend to be large and thus can be poorly represented by travel times averaged over the Census tract. Defining DTDs as a measure of individual-specific variables – income and impedance – allows DTDs to be addressed with policy interventions. The findings motivate future research correlating DTDs with licensure rates, enrollment in driver training, and safe driving outcomes to understand if DTDs can help explain health equity outcomes related to young driver safety.青少年因驾驶培训资源获取受限，往往难以考取驾照；美国部分州规定，18岁前申领驾照必须完成随车实操（behind-the-wheel, BTW）培训。本研究聚焦随车实操培训点的空间可达性，以及该类设施的地理分布与大都市区层面社会不平等指标的交叉关联，旨在识别驾驶培训荒漠（Driver Training Deserts, DTDs）——即无法便捷获取驾驶培训的地理区域。针对俄亥俄州哥伦布都会区，本研究以人口普查片区（Census tract）为分析单元收集社会经济变量，对公立与私立随车实操培训点进行地理编码，并测算各单元至最近培训点的出行时间。本研究将出行时间定义为：某一普查片区内所有1km×1km网格单元至最近随车实操培训点的平均出行时长，或最长出行时长。本研究采用空间统计方法（包括均质/非均质K函数），以判断随车实操培训点是否呈现空间集聚特征。全区域内随车实操培训点呈现显著空间集聚特征；即使纳入社会经济特征的基础空间分布进行校正，该集聚程度仍足以使培训点的空间集聚模式呈现统计学显著性。随后，本研究将驾驶培训荒漠（DTDs）界定为：贫困率与至随车实操培训点的出行时长均高于全区域75分位值的普查片区。研究结果显示，根据出行时间的不同定义，共有11至27个普查片区被界定为驾驶培训荒漠。该类区域内高贫困人口占比失衡（达8.7%至23.5%）；同时根据出行时间定义的不同，非裔美国人占比也显著偏高。从方法学层面来看，界定驾驶培训荒漠需要采用细粒度空间分析方法，原因在于郊区与农村地区的普查片区面积往往较大，仅用片区平均出行时长难以准确反映区域内的实际培训资源可达性。将驾驶培训荒漠界定为基于个体特异性变量（收入与出行阻抗）的指标，可为通过政策干预改善该类区域的培训资源可达性提供可行路径。本研究结论可为后续研究提供指引：未来可通过分析驾驶培训荒漠与驾照申领率、驾驶培训报名率及安全驾驶表现之间的关联，探究驾驶培训荒漠能否有效解释与青少年驾驶安全相关的健康公平问题。