Knowledge Resources

The evaluation found that the new weather alert system issued "on time" warnings 88.9 percent of the time and that messages were issued for 13 of the 15 weather events that merited weather warnings. However, a low level of primary message signs had messages posted during the weather events studied, and some of the messages were left active much longer than needed or desired, indicating that the weather notification system was not as effective in informing the public as it could be.

Several lessons can be drawn from this evaluation that will be helpful to other TMCs across the country as they explore ways to integrate weather information into the operations. They are described below:

• Provide in depth operator training for successful weather integration. Operators and management recognize the importance of training to assure well informed and consistent use of the system, but staff reductions have presented a challenge in delivering instruction. Training content should include clear operational policy guidance. In addition, training should provide an understanding of how and why the system upgrades and changes have been made and how they affect weather information flowing into the RTMC. Training content must strike an appropriate balance between the level of specificity in operational guidance for taking action in response to weather and providing flexibility for operators to use their experience and judgment in making decisions about their advisory and control actions.
• Clearly and consistently specify alert notification procedures. The thresholds for issuing warnings and alerts programmed into the notification system should be consistent with the written procedures and training content communicated to operators. Caltrans District 3 procedures call for operators to verify an alert with information from adjacent Road Weather Information System (RWIS) sensors, available third party weather services (National Weather Service, AccuWeather, local weather reports), and/or field observers (typically California Highway Patrol officers). Reconciling differences among these information sources takes experience and judgment on the operators' part. Procedures and training must account for the complexity of operator decision making based on information of varying accuracy, reliability and geographic focus.

The operators valued the warnings and alerts that were available to them, though they felt it necessary to verify their accuracy before taking any actions based on them. Overall, operators report that the automated alert system has made them more aware and allowed them to be more responsive to events as they unfold, thus providing the traveling public with enhanced mobility and safety during periods of inclement weather and dangerous road conditions.

This lesson suggests that operating procedures and guidelines for making decisions based on reported weather conditions, as well as training on how to respond to enhanced weather data, should be included as part of the implementation plan for future weather alert notification systems.