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Changeable Message Sign Displays During Non-Incident, Non-Roadwork Periods (2008)

Chapter: Chapter Four - Amber Alert Messages

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Suggested Citation:"Chapter Four - Amber Alert Messages." National Academies of Sciences, Engineering, and Medicine. 2008. Changeable Message Sign Displays During Non-Incident, Non-Roadwork Periods. Washington, DC: The National Academies Press. doi: 10.17226/23070.
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Suggested Citation:"Chapter Four - Amber Alert Messages." National Academies of Sciences, Engineering, and Medicine. 2008. Changeable Message Sign Displays During Non-Incident, Non-Roadwork Periods. Washington, DC: The National Academies Press. doi: 10.17226/23070.
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Suggested Citation:"Chapter Four - Amber Alert Messages." National Academies of Sciences, Engineering, and Medicine. 2008. Changeable Message Sign Displays During Non-Incident, Non-Roadwork Periods. Washington, DC: The National Academies Press. doi: 10.17226/23070.
×
Page 40
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Suggested Citation:"Chapter Four - Amber Alert Messages." National Academies of Sciences, Engineering, and Medicine. 2008. Changeable Message Sign Displays During Non-Incident, Non-Roadwork Periods. Washington, DC: The National Academies Press. doi: 10.17226/23070.
×
Page 41
Page 42
Suggested Citation:"Chapter Four - Amber Alert Messages." National Academies of Sciences, Engineering, and Medicine. 2008. Changeable Message Sign Displays During Non-Incident, Non-Roadwork Periods. Washington, DC: The National Academies Press. doi: 10.17226/23070.
×
Page 42
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Suggested Citation:"Chapter Four - Amber Alert Messages." National Academies of Sciences, Engineering, and Medicine. 2008. Changeable Message Sign Displays During Non-Incident, Non-Roadwork Periods. Washington, DC: The National Academies Press. doi: 10.17226/23070.
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39 BACKGROUND AMBER alert is a notification program to help locate miss- ing children believed to have been abducted. The Emergency Alert System (formerly known as the Emergency Broadcast System) is used to alert the public by means of television and radio in the event of an AMBER alert. America’s AMBER Plan Program through which emergency alerts are issued to notify the public about potential abductions of children is voluntary. As previously discussed, every state DOT and agencies that operate toll roads and own and operate CMSs, display AMBER alert messages. The AMBER Plan Program encourages the most effective methods of communicating with the public on behalf of abducted children. FHWA notes that CMSs are not always the most effective or safest method to disseminate informa- tion related to child abductions. Only a limited amount of information can be conveyed on a CMS. When there is a need to provide extensive information to motorists, FHWA states that it is critical that other types of traveler information media [e.g., 511, highway advisory radio (HAR), websites, and commercial radio] be used or that the messages on a CMS supplement these other media (19). CHANGEABLE MESSAGE SIGN MESSAGE CONTENT One of the issues of concern is the content of the CMS AMBER alert messages that will provide motorists with sufficient information for the Program to be effective. Ullman et al. (38,39) reported the results of laboratory studies con- ducted in 2004 in six cities in Texas concerning message con- tent. The authors evaluated driver preferences and ratings for message elements that should be included in an AMBER alert CMS message. The hierarchy of message elements selected by the participants was as follows, in order of importance: 1. Situation descriptor, 2. Vehicle descriptor, 3. License plate number, 4. Telephone number, and 5. Tune to radio action descriptor (HAR or local radio station). Ullman et al. also evaluated different terms for each of these message elements. The options that participants believed would best communicate the information are summarized in Table 12. Overall, there was no situation descriptor selected by the ma- jority of the participants to best communicate the information that a child has been taken, although the term AMBER ALERT was selected most often, (32%) followed by ABDUCTED CHILD (22%), and KIDNAPPED CHILD (15%). More than one-third (35%) of the participants stated their reason for not selecting AMBER ALERT as either they were not familiar with the term or they believed that other people would not be famil- iar with the term. Meanwhile, the primary reasons stated for the low response rate for MISSING CHILD or MISSING GIRL (BOY) descriptors was that the word MISSING has the conno- tation that a child would not be in a dangerous situation Out of five vehicle descriptors tested, 49% of the partici- pants selected the descriptor with the most information about the vehicle (i.e., BLUE MAZDA 05 PICKUP). For those who did not select this particular descriptor, the main reasons for not doing so were that the year of the vehicle was unnecessary information or would be too hard to determine (expressed by 37% of the subjects). The next most popular descriptor chosen was the one with the second most information (BLUE MAZDA PICKUP), selected by 38% of the participants. Overall, a total of 87% of the participants preferred the more detailed descriptors (BLUE MAZDA 05 PICKUP and BLUE MAZDA PICKUP). The majority of the participants (68%) selected the license number containing the “#” and “-” signs. According to the participants, this format separated the numbers and words so that the license plate number did not all run together (stated by 42% of the participants), and/or that the version without these symbols was confusing (expressed by 35% of partici- pants). Of course, the opposite view was held by the partici- pant minority who selected the other alternative, indicating that the “#” and “-” signs were either not needed or made the message harder to read and memorize. Eighty-seven percent of the participants selected the shorter and easier-to-remember telephone numbers, CALL 511 (59%) or DIAL 511 (28%). As would be expected, the main reason for not selecting the longer telephone numbers was that more numbers were too hard to remember. Of the three radio phrases tested, 63% of the participants selected TUNE TO 530 AM. The main reasons the other participants gave for not selecting this term were that the CHAPTER FOUR AMBER ALERT MESSAGES

alert information should be available on all stations anyway, that the participant does not listen to AM radio, or that the term local in the message was more informative to them. For the other descriptor alternatives, TUNE TO RADIO and TUNE TO LOCAL RADIO, the main reason given for not selecting them was that there was not a specific station num- ber provided. MESSAGE LOAD Early experiences with displaying AMBER alert messages indicated the need to include the vehicle license plate number if the vehicle make, model, and color were also displayed. Also, some agencies included a 10-digit telephone number that the motorist should call if the vehicle with the abducted child was seen. However, agencies that included the vehicle license plate and/or telephone numbers indicated that there was a tendency for some drivers to reduce speed in order to read the AMBER alert messages. Thus, there was evidence that the messages were too long and complex for motorists to read and comprehend. Ullman et al. (38) and Dudek et al. (40) reported on the results of studies conducted using a driving simulator and laptop computers to determine the effects of displaying li- cense plate and 10-digit telephone numbers in AMBER alert CMS messages. The first study was conducted using the Texas Transportation Institute Driving Environment Simula- tor in College Station, Texas. A laboratory study was also conducted in six cities in Texas. It was found, as expected, that the average reading time for AMBER alert messages with a license plate number was 40 significantly longer than the reading time for messages with- out a license plate number. In addition, the majority of sub- jects were not able to recall the entire number. Similarly, the average reading time for the messages with a 10-digit tele- phone number was significantly longer than the messages without a telephone number. Specifically, the following find- ings were noted: • A license plate number in a message is equivalent to more than three units of information, and • A 10-digit telephone number in a message is equivalent to more than three units of information. Thus, a message with a license plate number will exceed current effective message design guidelines that specify a maximum of four units of information in a message. Likewise, a message with a 10-digit telephone number will exceed cur- rent effective message design guidelines. In summary, AMBER alert CMS messages that contain a license plate number with the vehicle description (make, model, and color) can contain more than seven units of in- formation. Messages that include the license plate number and a 10-digit telephone number contain more than 10 units of information. In both cases, the number of informational units far exceeds the maximum four units of information guidelines. Therefore, drivers will not be able to read and comprehend the messages while traveling at typical freeway speeds. Drivers who attempt to read the messages before passing the CMS may reduce speed. STATE AMBER ALERT NETWORK AND POLICIES TMC procedures for displaying AMBER alert messages are normally influenced by statewide policies. An example of a state policy for Texas (41) follows: Message Element Term Percent of Participants AMBER ALERT 32 ABDUCTED CHILD 22 KIDNAPPED CHILD 15 MISSING CHILD 12 KIDNAPPED GIRL (BOY) 10 ABDUCTED GIRL (BOY) 6 1 MISSING GIRL (BOY) 3 BLUE MAZDA 05 PICKUP 49 BLUE MAZDA PICKUP 38 BLUE PICKUP 11 BLUE MAZDA 1 2 MAZDA PICKUP 1 LIC # SR8-493 68 3 LIC SR8 493 32 CALL 511 59 DIAL 511 28 CALL 888 769 5000 7 4 DIAL 888 769 5000 6 TUNE TO 530 AM 63 TUNE TO LOCAL RADIO 23 5 TUNE TO RADIO 14 TABLE 12 TERMS SELECTED BY LABORATORY PARTICIPANTS FOR AMBER ALERT MESSAGES IN TEXAS (n = 192) (39,40) The Texas Amber Alert Network was activated by Gov. Rick Perry to “ensure that every available re- source is used to return abducted children safely to their loved ones.” The Texas Department of Public Safety is in charge of the statewide sys- tem, but any Texas law enforcement agency has the ability to activate this network of resources when needed. When the system is activated, media outlets receive notification of an abducted child and TxDOT displays AMBER alert informa- tion on CMSs. To activate the network, the law enforcement agency with jurisdiction must deter- mine that the case meets the following criteria: • The child is 17 years of age or younger. • The local law enforcement agency believes that the child has been abducted, that is, unwillingly

41 It is important that AMBER alert messages are designed and displayed on CMSs uniformly across the state. In some state DOTs, there is one person who has the responsibility to co- ordinate the design and display of AMBER alert messages for the entire state. As a rule, the policy of agencies that operate CMSs is to turn off an AMBER alert message whenever there is a need to display messages of traffic or roadway situations that have an impact on traffic operations or safety. Also, some agencies limit the amount of time an AMBER alert message is displayed. For example, Caltrans limits the time that AMBER alert messages can be displayed to a maximum of 4 h. SURVEY RESULTS Message Content The first line of AMBER alert messages reported by the TMCs is summarized in Figure 35. The term AMBER ALERT is used for the situation descriptor by 39% of the TMCs. Eighteen percent display CHILD ABDUCTION, 12% display CHILD AMBER ALERT, and 8% display KIDNAPPED CHILD. The terms ABDUCTED CHILD, CHILD ABDUCTION ALERT, AMBER ALERT—CHILD ABDUCTION, and GIRL (BOY) ABDUCTION are displayed by 3% or fewer of TMCs. The other elements included in the message are shown in Table 13. The most common type of message included the vehicle make, vehicle model, vehicle color, license plate number, and telephone number (46%) in addition to the situation descriptor. The next most common type of message included the vehicle make, vehicle model, vehicle color, and license plate number (38%). Thus, 84% of the TMCs display AMBER alert messages that exceed the max- imum recommended four units of information. Therefore, the majority of motorists will not be able to read and Message Element Included in Message* M es sa ge Ty pe 1 M es sa ge Ty pe 2 M es sa ge Ty pe 3 M es sa ge Ty pe 4 M es sa ge Ty pe 5 M es sa ge Ty pe 8 M es sa ge Ty pe 7 M es sa ge Ty pe 6 M es sa ge Ty pe 9 Vehicle Make X X X X Vehicle Model X X X X Vehicle Color X X X X X X License Plate No. X X X X X X X Telephone No. X X X X Radio Station Percent of TMCs X X * In addition to a situation descriptor (e.g., AMBER alert). 46% 38% 1% 1% 1% 1% 4% 3% 5% TABLE 13 PERCENT OF TMCs DISPLAYING SPECIFIC MESSAGE ELEMENTS IN AMBER ALERT MESSAGES 39 18 12 8 3 3 2 1 14 0 10 20 30 40 50 1 Message Pe rc en t o f T M Cs AMBER ALERT CHILD ABDUCTION CHILD AMBER ALERT KIDNAPPED CHILD ABDUCTED CHILD CHILD ABDUCTION ALERT AMBER ALERT - ABDUCTED CHILD GIRL (BOY) ABDUCTION Did not give example messages FIGURE 35 Message situation descriptor contained in AMBER alert messages. taken from his/her environment without permis- sion from the child’s parent or legal guardian who commits an act of murder or attempted murder during the time of the abduction • The local law enforcement agency believes that the missing child is in immediate danger of se- rious bodily harm or death. • The local law enforcement agency confirms that an investigation has taken place that veri- fies the abduction and has eliminated alterna- tive explanations for the missing child. • Sufficient information is available to dissemi- nate to the public that could assist in locating the child, the suspect, or the vehicle used in the abduction. • Upon verification of the activation request, the Governor’s Division of Emergency Management determines the circumference of the search area and issues the alert. Alerts are distributed to: – TxDOT’s Traffic Management Center (for messages on highway signs), – National Weather Service’s Texas Warning System (for broadcast on radio and televi- sion stations), – Law enforcement agencies, – Texas Missing Persons Clearinghouse, and – Texas Office of the Governor.

comprehend the messages while traveling at typical free- way speeds. Public Response The reported public response to AMBER alert messages is summarized in Figure 36. Overall, 75% of the TMCs stated that the response from the public has been very favorable (45%) or favorable (30%). Only 9% reported that the public response has been somewhat favorable (4%) or neutral (5%). Sixteen percent of the TMCs stated that they did not have sufficient in- formation to judge public response to AMBER alert messages. Examples of Typical AMBER Alert Messages Exhibit 9 shows examples of typical AMBER alert messages. A review of the AMBER alert messages currently being displayed by TMCs indicates a lack of uniformity of message content, particularly with the situation descriptor. 42 Experiences and Lessons Learned Many of the TMCs reported positive experiences with AMBER alert messages. Some TMCs highlighted the importance of displaying information that is accurate, timely, and includes the license plate number. Others found that the messages that they posted were too long for drivers to read and recall, and drivers tended to slow to read the messages. A summary of the experiences and lessons learned from displaying AMBER alert messages follows: • AMBER alert messages are well received by the public (20 TMCs). • Messages should be displayed accurately and in a timely manner (4 TMCs). • Too much information is being displayed on our mes- sage; drivers cannot read and comprehend the messages (3 TMCs). • Drivers tend to slow down to read certain types of AMBER alert messages (3 TMCs). • Point motorist to tune to local media for additional infor- mation (4 TMCs). • Keep the message simple (2 TMCs). • Message changed to CHILD ABDUCTION since AMBER was confused with homeland security color code several years ago (2 TMCs). • The display of a message with a vehicle make, model, and color, but not a license plate could result in an in- correct vehicle being approached (2 TMCs). • Make sure information displayed is clear and correct (1 TMC). • Wait until sufficient correct information is available before activating CMSs (1 TMC). • Only display messages when sufficient vehicle descrip- tive data are available (1 TMC). 45 30 4 5 0 0 0 16 0 10 20 30 50 40 Public Response Pe rc en t o f T M Cs Ve ry fav or ab le Fa vo ra ble So m ew ha t fa vo ra ble Ne utr al So m ew ha t u nfa vo ra ble Un fav or ab le Ve ry un fav or ab le No in for ma tio n a va ilab le FIGURE 36 Public response to AMBER alert messages. Exhibit 9 One-Phase Messages AMBER ALERT BROWN FORD TRUCK TAG BHU-1234 ABDUCTED CHILD CALL 511 FOR INFO *HP IF SEEN CHILD ABDUCTION BLUE FORD VAN CA LIC 901ABC123K Example 1 Example 2 Example 3 CHILD AMBER ALERT 1990 WHITE HONDA TN LIC 9885 GIRL ABDUCTED MO LIC# 123-ABC WHITE FORD PICKUP CHILD ABDUCTION TUNE TO LOCAL RADIO OR 1610 AM Example 4 Example 5 Example 6

43 • We provide detailed vehicle information on half of our CMS displays and direct travelers to our HAR frequency on the others where more complex information and in- structions are available (1 TMC). • Get as much information as possible from the police agency (1 TMC). • Make sure that accurate information is provided by the law enforcement agency (1 TMC). • We do not get the information fast enough from the police agency and have been publicly embarrassed be- cause of untimely information (1 TMC). • License plate number is needed otherwise messages cause large number of inquiries to local law enforcement agencies (1 TMC). • We do not display 7–10 digit phone numbers or license plate numbers. • AMBER alert messages on too many CMSs on the same freeway result in complaints from the public (1 TMC). • When messages are not displayed immediately after an AMBER alert is announced, we receive inquiries from the media when we do not post CMS messages because we do not have accurate or timely information from the police agency (1 TMC). • Law enforcement can be inundated with telephone calls (1 TMC). • Always get a complete license plate, and include which state it was issued in (1 TMC). • If license plate number is not known, would recommend that CMS not be used (1 TMC). • Very effective tool. Recently, a motorist noticed the car over 200 miles away. This led to an arrest and recovery of the children (1 TMC). • Public response to these messages is very good, based on questions generated from the public. Those ques- tions have driven policy change to post all the informa- tion on HAR (1 TMC). • We had to change our hardware and software to post messages statewide in a timely manner (1 TMC). • Would be helpful to have MUTCD or FHWA suggest AMBER alert CMS message text and then do one coor- dinated public awareness campaign (1 TMC). • We used to say CALL 911 on the bottom line of AMBER alert messages, but we dropped that because we believe it is assumed that is the thing to do if you spot the vehicle in question (1 TMC). • At the request of state police, we post AMBER messages statewide. When we don’t have a vehicle license plate, we post a tune-to-local-media message. Sometimes when the AMBER alert is in one part of the state, media in other parts aren’t broadcasting the message, which cre- ates some confusion when the tune-to-local-media mes- sage is posted (1 TMC). • If we do not have the vehicle information, we put up: AMBER ALERT CHECK LOCAL MEDIA (or TUNE TO HAR) (1 TMC). • First time we did it, the message was to tune to local radio. They may only play the information every half-hour or hour. Received many complaints that the person tuned in and didn’t hear anything. We now read entire broadcast script on the HAR (1 TMC). • Keep deployment period on a specific CMS short, say 6 h maximum (1 TMC). • There must be memorandum of understanding between the law enforcement agency and DOT (1 TMC). • We must have a clear process in place to put up messages on CMSs (1 TMC). Concerns and Challenges The primary concerns and challenges reported by the TMCs dealt with the delays in getting accurate and timely infor- mation from law enforcement agencies and getting timely Two-Phase Messages KIDNAPPED CHILD RED DODGE PU CALL POLICE KIDNAPPED CHILD (City) (State) XX LC 123 ABC Phase 1 Phase 2 Example 1 CHILD AMBER ALERT RED DODGE PU IF SEEN CALL 911 XX LIC 123 ABC Phase 1 Phase 2 Example 2 Example 3 CHILD ABDUCTION ALERT BLUE CHEVY PK UP XX 1234AB CALL 911 Phase 1 Phase 2 ABDUCTED CHILD RED CHEVY TRUCK TAG XX ABC 1234 AMBER ALERT CALL 511 INFO *HP IF SEEN Phase 1 Phase 2 Example 4

information when the AMBER alert is no longer in effect. In addition, there were concerns about the specific message design so that the information displayed on the CMSs does not exceed the reading and understanding capabilities of drivers. A summary of the specific comments from the TMCs follows: • We experience delays in receiving information fast enough from the police agency in order to display timely information (12 TMCs). • We experience problems with receiving correct/complete information (including license plate number) from the police agency in order to display accurate and complete information (12 TMCs). • We encounter delays in receiving information from the police agency when the AMBER alert is no longer in effect so that the CMS message can be deleted in a timely fashion (4 TMCs). • Deciding what information to display because too much information can be too long for drivers to read, causing drivers to slow down to read the signs (4 TMCs). • CMS message format is dictated by the state police (2 TMCs). • Condensing messages into concise, actionable mes- sages for the CMS environment is our greatest chal- lenge (1 TMC). • Concerned with liability of posting specific information (1 TMC). 44 • Being asked or directed to display an AMBER alert message with incomplete vehicle description informa- tion (1 TMC). • Driver distractions when trying to write down informa- tion while driving (1 TMC). • How long to display messages (1 TMC). • Coordinating our software with the law enforcement agency software. They have other systems that need inputting first, and ours is last. Need to tie these systems together (1 TMC). • Concerned about implications of posting vehicle infor- mation (1 TMC). • Difficulty in getting uniformity of messages among dif- ferent CMS sizes (e.g., permanent and portable CMSs) (1 TMC). • Improving communications between TMCs (1 TMC). • We need software that can display the same message simultaneously on all signs in the system (as you would like during an AMBER event) (1 TMC). • Sometimes the CMS is outside a 250-mile range of occurrence (1 TMC). • Sometimes they prematurely call statewide alerts when they are too far from our area (1 TMC). • Bi-state rules and policies. Regional or not? Coordina- tion with media (1 TMC). • Driver emotions and reaction to information or identi- fying suspect in traffic. Motorists who take the law into their own hands (1 TMC).

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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 383: Changeable Message Sign (CMS) Displays During Non-Incident, Non-Roadwork Periods explores the use of CMSs to convey messages on non-recurrent, environmental, special event traffic, and other special problems.

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