TheWireless Emergency Alert (WEA) service allows short text messages to be broadcast to all capable mobile devices in a specified geographic area. Although it enjoys nationwide reach, the current WEA service has limitations that impede its public acceptance. These limitations include imprecise geographical targeting of alerts, which reduces the alerts’ relevance to many recipients, increasing the likelihood of these recipients to opt out of receiving alerts or stop paying attention. The growing capabilities of smart phones, such as improved location awareness and increased computing power, provide opportunities to alleviate the limitations by personalizing targeted alerts and allowing optimized alert delivery decisions. Motivated by these opportunities, we designed and developed a prototypical, enhanced end-to-end WEA service that includes an alert creation subsystem, a message delivery subsystem, and a smart phone application for capturing, processing, and presenting simulated alerts to recipients. We conducted two public trials with over 225 subjects to evaluate several WEA enhancements using this service. The evaluated enhancements included (1) augmenting WEA messages with high- information maps, (2) precise geographical targeting of alerts, and (3) use of the recipient’s location history to influence the alert delivery decision. Our results suggest significant added value for all three enhancements, making them worthy of consideration for future WEA implementations.