Common-carrier parcel lockers have emerged as a secure, automated, self-service means of delivery consolidation in congested urban areas, which are believed to mitigate last-mile delivery challenges through reducing out-of-vehicle delivery times and consequently vehicle dwell times at the curb. However, little research exists to empirically demonstrate the environmental and efficiency gains from this technology. In this study, we designed a nonequivalent groups pre-test/post-test control experiment to estimate the causal effects of a parcel locker on delivery times in a residential building in downtown Seattle, WA. The causal effects are measured in terms of vehicle dwell time and the time delivery couriers spend inside the building, through the difference-in-difference method and using a similar nearby residential building as a control. The results showed a statistically significant decrease in time spent inside the building, and small yet insignificant reduction in delivery vehicle dwell time at the curb. The locker was also well received by the building managers and residents.

公共承运商包裹储物柜已成为拥挤城市地区的一种安全、自动化、自助式的交付整合方式，据信通过减少车外交付时间从而减少车辆停留时间来缓解最后一英里交付挑战路边。然而，很少有研究以经验证明该技术在环境和效率方面的收益。在这项研究中，我们设计了一个非等效组测试前/测试后控制实验，以估计包裹储物柜对华盛顿州西雅图市中心一栋住宅楼交付时间的因果影响。因果效应是根据车辆停留时间和送货快递员在建筑物内花费的时间，通过差分法并使用附近的类似住宅楼作为对照来衡量的。结果显示，在建筑物内花费的时间在统计上显着减少，而送货车辆在路边停留的时间减少幅度很小但微不足道。该储物柜也受到大厦管理人员和住户的一致好评。