Public Perception of Safety Messages and Public Service Announcements on Dynamic Message Signs in Rural Areas

Chapter 5. Findings and Recommendations

This section summarizes the analysis findings for each hypothesis, provides the conclusions from the evaluation, and present recommendations for displaying public service announcements (PSAs) and safety messages on dynamic message signs (DMS) in rural areas, as well as future research needs or recommendations for changes in key reference documents.

Study Findings

Safety Campaign Messages Posted During this Study

The displayed information type changed by site and round (R1, R2, R3) as shown in Table 3. Seatbelt-related messages were the most common message campaign theme for the four sites during the data collection period, followed by general safety information. Note that only catchy messages were shown for the duration of survey activities in Missouri. As such, this presents an opportunity to examine the possible impacts of catchy versus traditional messages on DMS. However, it is important to keep in mind a variety of factors that could cause bias, including geographic differences, site characteristics, the relative proximity of the DMS to the survey, and the safety campaign or PSA type being displayed.

Table 3. Safety Campaign Messages Posted During this Study.

State, Corridor	Survey Round, 2015 Dates	Safety Campaign Message Content*	Information Type
Nevada, I-80	R1: 5/4-5/7;R2: 10/5-10/7	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	General Safety
Nevada, I-80	R1: 5/4-5/7;R2: 10/5-10/7	DRIVE SAFELY MAKE IT ZERO FATALITIES	General Safety
Minnesota/Wisconsin, I-94	R1: 5/26-5/28	EXTRA SEAT BELT PATROLS NOW, CLICK IT OR TICKET	Seatbelt
Minnesota/Wisconsin, I-94	R1: 5/26-5/28	BUCKLE UP, __ TRAFFIC DEATHS THIS YEAR	Seatbelt
Minnesota/Wisconsin, I-94	R2: 9/15-9/17;R3: 10/26-10/29	WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES	Mixed: Seatbelt, Distracted Driving, DUI, EMS
Minnesota/Wisconsin, I-94	R2: 9/15-9/17;R3: 10/26-10/29	BUCKLE UP, __ TRAFFIC DEATHS THIS YEAR	Mixed: Seatbelt, Distracted Driving, DUI, EMS
Minnesota/Wisconsin, I-94	R2: 9/15-9/17;R3: 10/26-10/29	JUST DRIVE, TEXTING CAN WAIT	Mixed: Seatbelt, Distracted Driving, DUI, EMS
Minnesota/Wisconsin, I-94	R2: 9/15-9/17;R3: 10/26-10/29	PLAN AHEAD DESIGNATE A SOBER DRIVER	Mixed: Seatbelt, Distracted Driving, DUI, EMS
Kansas, I-70	R1: 7/6-7/9	MOVE OVER FOR HIGHWAY WORKERS	Work zone/EMS
Kansas, I-70	R1: 7/6-7/9	MOVE OVER FOR EMERGENCY VEHICLES	Work zone/EMS
Kansas, I-70	R2: 9/8-9/11	DON’T DRIVE DRUNK, ALCOHOL LAWS ENFORCED	DUI and EMS
Kansas, I-70	R2: 9/8-9/11	MOVE OVER FOR EMERGENCY VEHICLES	DUI and EMS
Missouri**, I-44	R1: 7/13-7/15	It's a Passing Lane…Not a Cruising Lane	Safe driving and Seatbelt
Missouri**, I-44	R1: 7/13-7/15	Pass on Left, Drive on Right	Safe driving and Seatbelt
Missouri**, I-44	R1: 7/13-7/15	Changing Lanes? Show Me Your Blinker	Safe driving and Seatbelt
Missouri**, I-44	R1: 7/13-7/15	Turn Signals…The Original Instant Message	Safe driving and Seatbelt
Missouri**, I-44	R1: 7/13-7/15	Unbuckled? Seriously?	Safe driving and Seatbelt
Missouri**, I-44	R1: 7/13-7/15	Buckle Up, Windshields Hurt	Safe driving and Seatbelt
Missouri**, I-44	R2: 10/14-10/15	It's No Trick, Seatbelts Are a Treat	Seatbelt
Missouri**, I-44	R2: 10/14-10/15	Buckle Up, Have a Nice Day	Seatbelt
Missouri**, I-44	R2: 10/14-10/15	That Seat Belt Looks Good On You	Seatbelt
Missouri**, I-44	R3: 11/2-11/5	All Buckled, All Seats, All the Time	Seatbelt
Missouri**, I-44	R3: 11/2-11/5	That Seat Belt Looks Good On You	Seatbelt
Missouri**, I-44	R3: 11/2-11/5	Buckle Up, Windshields Hurt	Seatbelt
Missouri**, I-44	R3: 11/2-11/5	Give Thanks, Buckle Up, Drive Safely	Seatbelt
Missouri**, I-44	R3: 11/2-11/5	Thanks for Wearing Your Seat Belt	Seatbelt
Missouri**, I-44	R3: 11/2-11/5	Thanks for Buckling Kids in Car Seats	Seatbelt

^*Messages that were asked to be interpreted during surveys are shown in bold.
^**Missouri posts PSAs and safety messages in Title Case, and not ALL CAPS.

Traveler Type Distribution

Table 4 presents the number of travelers encountered during each round of surveying at each location, and whether they took the survey or their reason for not participating. It should be noted that the information presented in the table hints at valuable, but imperfect information. There are a number of reasons for people to refuse to take the survey, and it is possible that travelers say they did not see a DMS just to avoid further engagement with the survey team. In other instances, travelers verbally expressed frustration that they had not seen the DMS, which could be the result of several factors. The DMS in Kansas, Missouri, and Wisconsin are typically placed by the side of the road, the DMS in Nevada were either overhead or in the median, and the DMS in Minnesota were overhead, and a traveler passing or closely following a truck may not see the DMS, for example. In other cases, the survey intercept location may have been further away from the DMS and therefore less memorable to travelers. While distracted driving is an issue and there is an interest in understanding whether signs are not visible to travelers or a distraction that travelers ignore, for example, the focus of this survey effort was to capture feedback based on direct recall of recently seeing the message. As with any similar survey effort, unpleasant weather or a location with busy travelers can cause reduced survey participation, which may vary by corridor or day.

Table 4. Number of Travelers Encountered.

State	Survey Round	Screener Results (Did not take survey): Refused before determining eligibility	Screener Results (Did not take survey): Eligible and Refused	Screener Results (Did not take survey): Ineligible (did not see DMS)	Screener Results (Did not take survey): Ineligible (did not travel on corridor)	Screener Results (Did not take survey): Other barrier, e.g., language	Screener Results (Did not take survey): Subtotal	Survey Responses	Total Travelers
NV	R1	153	68	84	26	14	345	204	549
NV	R2	23	49	40	2	11	125	93	218
MN/WI	R1	141	91	188	7	3	430	160	590
MN/WI	R2	53	64	62	0	15	194	233	427
MN/WI	R3	352	196	67	1	5	621	289	910
KS	R1	80	125	115	0	5	325	177	502
KS	R2	30	54	31	7	6	128	216	344
MO	R1	141	101	70	0	10	322	181	503
MO	R2	34	59	35	3	7	138	102	240
MO	R3	304	247	200	0	22	773	282	1055
Total		1311	1054	892	46	98	3401	1937	5338

Table 5 and the corresponding Figure 8 summarize survey participants by group for each site. Infrequent travelers comprised the highest percentage of survey participants in Kansas, Missouri, and Nevada. Surveys on these corridors were conducted at rest areas, as these locations seemed to provide the highest volume of travelers to intercept who had actually been on the corridor to see a DMS. Frequent travelers often consist of individuals whose origin and destination are not necessarily directly off of the highway and not far enough apart to merit an en route stop near the highway. Truckers consist of a lower percentage of travelers on each corridor as a whole.

Table 5. Number of Survey Participants per Corridor, and Percentage by Traveler Type.

State	Corridor	Number of Survey Participants: Infrequent	Number of Survey Participants: Frequent	Number of Survey Participants: Truckers	Number of Survey Participants: Total
Nevada	I-80	122	84	91	297
Nevada	I-80	41%	28%	31%	100%
Minnesota/Wisconsin	I-94	225	272	185	682
Minnesota/Wisconsin	I-94	33%	40%	27%	100%
Kansas	I-70	195	113	85	393
Kansas	I-70	50%	29%	22%	100%
Missouri	I-44	285	112	168	565
Missouri	I-44	50%	20%	30%	100%
OVERALL		827	581	529	1937
OVERALL		43%	30%	27%	100%

Note: percentages may not sum to 100 exactly due to rounding.

Gender Distribution

Table 6 and Figure 9 summarize the gender distribution among participants. In all four sites there were significantly more male participants (around 70 percent) than female participants. Anecdotally, this appeared to be reflective of the driving population encountered by the survey team. The proportions of male and female travelers intercepted for each location generally reflect the percentages of survey participants.

Table 6. Number of Survey Participants per Corridor, and Percentage by Gender.

State	Corridor	Number of Survey Participants: Female	Number of Survey Participants: Male	Number of Survey Participants: Total
Nevada	I-80	85	212	297
Nevada	I-80	29%	71%	100%
Minnesota/Wisconsin	I-94	185	497	682
Minnesota/Wisconsin	I-94	27%	73%	100%
Kansas	I-70	129	264	393
Kansas	I-70	33%	67%	100%
Missouri	I-44	176	389	565
Missouri	I-44	31%	69%	100%
OVERALL		575	1362	1937
OVERALL		30%	70%	100%

Frequency of Seeing General Safety Campaign Messages on DMS

Table 7 and Figure 10 provide the panel composition based on frequency of seeing the safety campaign messages on DMS. Kansas, Missouri, and Nevada survey participants had a very similar distribution in terms of self-reported frequency of seeing safety campaign messages on DMS. In those sites, the highest percentage (around 37 percent) of travelers see safety campaign message on DMS less than one time per month, with the second highest (around 27 percent) at 1-3 times per month. In Minnesota/Wisconsin, the participant groups were roughly switched with the largest group (around 34 percent) being travelers who reported seeing safety campaign message 1-3 times per month, followed by 26 percent of travelers who reported a frequency of less than one time per month. The switch in Minnesota/Wisconsin may reflect the slightly higher proportion of frequent travelers versus infrequent travelers, and the proximity to the Minneapolis-St. Paul metro area where DMS are common.

Table 7. Number of Survey Participants per Corridor, and Percentage by Frequency of Seeing Safety Campaign Messages on DMS.

State	Corridor	Number and Percentage of Survey Participants: <1 time per month	Number and Percentage of Survey Participants: 1-3 times per month	Number and Percentage of Survey Participants: 1-3 times per week	Number and Percentage of Survey Participants: >3 times per week	Number and Percentage of Survey Participants: Total1
Nevada	I-80	108	83	38	67	296
Nevada	I-80	36%	28%	13%	23%	100%
Minnesota/Wisconsin	I-94	175	232	104	170	681
Minnesota/Wisconsin	I-94	26%	34%	15%	25%	100%
Kansas	I-70	145	106	56	85	392
Kansas	I-70	37%	27%	14%	22%	100%
Missouri	I-44	215	147	76	126	564
Missouri	I-44	38%	26%	13%	22%	100%
OVERALL		643	568	274	448	1933
OVERALL		33%	29%	14%	23%	100%

¹Four participants did not provide inputs.
Note: percentages may not sum to 100 exactly due to rounding.

Hypotheses Area and Survey Questions

Table 8 lists the evaluation hypotheses and the related survey questions that were utilized to evaluate the hypotheses.

For each of the hypotheses, the following results begin with a simple summary of responses by site. Following that simple summary, a statistical ANOVA model has been fit to the responses for each question. That model compares the responses under several groupings:

1. Traveler type (i.e., infrequent, frequent, truckers).
2. Age (i.e., 16-55, over 55).
3. Gender.
4. Round (i.e., survey responses were evaluated over 2 or 3 rounds of data collection).
5. Frequency of seeing DMS messages (i.e., <1 time per month, 1-3 times per month, 1-3 times per week, >3 times per week).

The responses to the survey questions are in the form of percentages. Each survey question either naturally yields a dichotomous response, or has been transformed into one (e.g., scaled response of "Agree" and "Strongly Agree" are added together to generate a single response for "Agree"). When the dichotomous response is fit to the logistic regression statistical model, the estimates for the variables of interest compared between levels are provided as odds ratios. The odds ratio is the probability of being in a class divided by probability of not being in the class for one condition divided by the odds of the comparison condition. The reported odds ratios are accompanied by statistical 95 percent confidence intervals. If estimated odds ratios exceed 1.0, it means the odds of the condition are higher for the comparison group. The converse is true for odds ratios less than 1.0. If the 95 percent confidence interval is either wholly above 1.0 or wholly below 1.0, it provides evidence that the survey data collected identify the difference as significant. The interpretation of the significance is that the data collected provide a probability of no more than one chance in 20 that the difference was due to random chance. Instead, it is highly likely the direction of the observed outcome reflects truth.

For most questions, the statistical models were fit separately for each site. For a few hypotheses, sites were combined.

Table 8. Hypothesis Areas and Survey Questions.

Evaluation Area	Hypotheses	Evaluation Questions
Awareness	A significant percentage of travelers have observed an actual safety message and/or PSA on a DMS	Did you observe one of these safety-related messages on DMS?
Understanding	Drivers can understand the messages on the DMS	What does "*specific message*" mean to you? Do you agree that "*" is understandable?
Behavior Changes	The display of a PSA on a DMS does not cause traffic to slow down or other congestion	Have these messages ever caused you to slow down?
Behavior Changes	The contents of the PSA cause a change in behavior by the travelers (e.g., more aware, looking for an AMBER alert license plate, etc.)	After seeing the messages did you do anything differently? Has seeing one of these messages ever caused you to change your driving?
Opinions	Travelers believe that DMS for safety awareness and PSA messages are appropriate	Do you agree that the message is appropriate?
Opinions	Travelers believe that DMS should only be used for traffic-related messages	What types of message do you think should be displayed on DMS?
Opinions	Travelers believe that it would be more effective and/or less distracting to motorists to disseminate safety awareness messages and PSAs via other means	Which way of communicating safety-related information do you think is best?
Opinions	Travelers perceive a value of safety awareness and PSA messages on DMS	Do you agree that the message raised your awareness of the issue?

Evaluation of Awareness

• Hypothesis: A significant percentage of travelers have observed an actual safety message and/or PSA on a DMS.
  • Question: Did you observe one of these safety-related messages on DMS?

Because all survey participants already said they had seen a DMS in order to be eligible to take the survey, the number of travelers encountered by survey administrators, presented in Table 4, provide some insight for this hypothesis. In total for all survey rounds, 2991 travelers (77 percent, this number includes the 1937 survey participants and 1054 travelers who were eligible but refused to take the survey), responded that they had seen the DMS, compared with 892 travelers who had not.

Did you observe one of these safety-related messages on the DMS?

Participants were permitted to select from a list of safety campaign messages that were truly posted, as well as a false message (i.e., "smoking is harmful to your health"). They also were permitted to respond that they had not seen any message. The survey allowed any combination of responses. In summarizing the responses, five mutually exclusive categories were identified. There were some participants whose responses were coded as "invalid", as they selected an illogical option (i.e., selecting "None" and one or more messages at the same time). These data were removed from the modelling dataset, but are included in the Table 5 summary.

From Table 9 and Figure 11, it can be see that a majority of the participants, between 60 to 89 percent, observed at least one of the specified safety-related messages on DMS, indicating a high awareness level of the posted safety-related messages. Compared with other sites, Missouri appears to have the lowest percentage of participants reporting that they observed at least one of the messages, and the highest percentage of participants who did not see any of the listed messages in the survey. This could be due to several factors, including the fact that a greater number of messages were shown during the survey periods and DMS were further upstream from the survey location in Missouri than at other corridors. Missouri is also the only site where catchy messages were displayed on the DMS.

Table 9. Number of Survey Participants per Corridor, and Percentage on Whether They See Identified Safety Campaign Messages on DMS.

State	Round	Number and Percentage of Survey Participants: At Least One True	Number and Percentage of Survey Participants: False Message	Number and Percentage of Survey Participants: True & False	Number and Percentage of Survey Participants: None	Number and Percentage of Survey Participants: Invalid	Number and Percentage of Survey Participants: Number of Participants
Nevada	R1	71%	2%	11%	15%	1%	204
Nevada	R2	81%	1%	12%	1%	5%	93
Minnesota/Wisconsin	R1	88%	0%	9%	2%	1%	160
Minnesota/Wisconsin	R2	85%	0%	13%	1%	2%	233
Minnesota/Wisconsin	R3	86%	0%	9%	5%	0%	289
Kansas	R1	89%	1%	5%	5%	2%	177
Kansas	R2	79%	0%	19%	1%	1%	216
Missouri	R1	77%	1%	5%	17%	1%	181
Missouri	R2	60%	3%	10%	24%	4%	102
Missouri	R3	70%	1%	12%	17%	1%	282
All Participants		1529 (79%)	12 (1%)	206 (11%)	163 (8%)	27 (1%)	1937

Note: At least one true = the participant reported to have observed at least one of the true DMS message listed in Table 3, and not the false message ("smoking is harmful to your health").
False message = only the false message ("smoking is harmful to your health") was chosen by the participant.
True & False = the participant chose both the false message and one or more of the true messages.
None = the participant indicated that they did not observe any of the messages listed in the question.
Invalid = the participant chose both "None" and one or more of the listed messages.
Percentages may not sum to 100 exactly due to rounding.

For modeling purposes, participant responses were grouped into two categories. The first category was participants who observed at least one (true) safety-related message, while other types of responses were aggregated as the second category. A binary logistic regression model was fit with traveler type, age, gender, round, and frequency of seeing a safety-related message during general travels as the predictors. The modeled probability was of observing at least one of the (true) listed safety-related messages.

Table 10 below and Figure C-1 through Figure C-4 in Appendix C show the estimated odds ratios and confidence intervals from the model. Infrequent travelers had higher levels of awareness in Kansas, Minnesota/Wisconsin, and Nevada followed by frequent travelers, while truckers had the lowest awareness level. However, the differences were not statistically significant in either Kansas or Minnesota/Wisconsin; infrequent travelers reported statistically significantly higher awareness level than truckers in Nevada. Anecdotally, truckers commented more than other travelers that DMS messages were a waste of money or not relevant to them. Missouri had a different pattern, with infrequent travelers having significantly lower awareness level than frequent travelers. This could be the result of the relatively longer distance of the DMS from the survey location and fewer rural DMS located upstream of the Missouri survey location than in other corridors.

Younger travelers tended to report a higher awareness of the listed safety-related message for all four sites. However, only in Minnesota/Wisconsin was a statistically significant difference found.

The impact of gender varied, but was found to be significant in Nevada, where females were found to be significantly less aware of the listed safety-related message than males.

Survey date/round had significant impacts for all sites other than Minnesota/Wisconsin for unknown reasons, but the direction of the conclusion varied. Response levels did not appear to be impacted significantly as a function of how often DMS signs were reported to be seen.

Table 10. Odds Ratios and 95 Percent Confidence Limits – Awareness Hypothesis of Observing an Actual Safety Message and/or PSA on a DMS by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	1.5 (0.7, 3.3)	1.1 (0.6, 2.1)	1.3 (0.6, 2.6)	0.5 (0.3, 0.9)
TravelerType 1 vs 3	2.6 (1.1, 6.2)	1.5 (0.7, 3.0)	2.2 (0.9, 5.0)	0.7 (0.4, 1.1)
TravelerType 2 vs 3	1.8 (0.8, 3.8)	1.3 (0.7, 2.4)	1.7 (0.9, 4.0)	1.4 (0.7, 2.6)
Age 1 vs 2	1.5 (0.8, 2.8)	2.5 (1.5, 4.2)	1.8 (1.0, 3.4)	1.3 (0.9, 2.0)
Gender Female vs Male	0.5 (0.3, 1.0)	1.7 (1.0, 3.0)	1.2 (0.6, 2.2)	0.9 (0.6, 1.4)
Round R1 vs R2	0.4 (0.2, 0.9)	1.2 (0.6, 2.3)	2.9 (1.5, 5.4)	2.0 (1.1, 3.5)
Round R1 vs R3		1.2 (0.6, 2.2)		1.5 (0.9, 2.3)
Round R2 vs R3		1.0 (0.6, 1.7)		0.7 (0.5, 1.2)
DMSFrequency 1 vs 2	0.7 (0.3, 1.7)	0.9 (0.5, 1.7)	1.4 (0.7, 3.0)	0.8 (0.5, 1.3)
DMSFrequency 1 vs 3	0.6 (0.3, 1.3)	0.8 (0.4, 1.6)	0.9 (0.4, 1.9)	0.8 (0.5, 1.4)
DMSFrequency 2 vs 3	0.8 (0.4, 1.6)	0.9 (0.5, 1.7)	0.7 (0.3, 1.3)	1.1 (0.6, 1.8)

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

Evaluation of Understanding

• Hypothesis: Drivers can understand the messages on the DMS.
  • Question: What does "*specific message*" mean to you?
  • Question: Do you agree that “*” is understandable?

What does the identified message mean to you?

Survey participants were asked to select from multiple choice options to determine if they understood the meaning of one of the safety messages currently being displayed in the corridor. For each site and survey round, different message were selected for the participant to interpret. As shown in Table 11, most travelers correctly interpreted the messages posted during each survey round for each corridor. Minnesota/Wisconsin Round #1 had the highest correct interpretation rate at 95 percent when asked to correctly interpret "Click it or ticket." However, Minnesota/Wisconsin also had the lowest correct interpretation rate (58 percent) at Round 2 when asked to correctly interpret, "WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES."

Table 11. Number of Survey Participants per Corridor, and Percentage on the Understanding of the Listed Message.

State	Round	Number and Percentage of Survey Participants: Incorrect	Number and Percentage of Survey Participants: Correct	Number and Percentage of Survey Participants: No Data	Number and Percentage of Survey Participants: Total
Nevada	R1	6%	93%	1%	204
Nevada	R2	6%	92%	1%	93
Minnesota/Wisconsin	R1	4%	95%	1%	160
Minnesota/Wisconsin	R2	42%	58%	0%	233
Minnesota/Wisconsin	R3	34%	65%	0%	289
Kansas	R1	22%	76%	2%	177
Kansas	R2	35%	65%	0%	216
Missouri	R1	11%	88%	1%	181
Missouri	R2	16%	84%	0%	102
Missouri	R3	8%	91%	0%	282
All Participants		396 (20%)	1528 (79%)	13 (1%)	1937

A binary logistic model was fit to the data with the probability of understanding the identified message correctly as the response and traveler type, age, gender, round, and frequency of seeing safety-related message during general travels as the predictors as shown in Table 12 and Figure C-5 through Figure C-8 in Appendix C. No statistically significant impacts were found in either Kansas or Minnesota/Wisconsin corridors. In Nevada, truckers were found to have a significantly lower understanding level than both infrequent travelers and frequent travelers. In Missouri, infrequent travelers' understanding of the identified message was significantly lower than frequent travelers. This may be a result of frequent drivers being more familiar with the catchy messages posted in Missouri.

Only in Minnesota/Wisconsin was a statistically significant impact of age observed where younger travelers understood the identified message better. Females were found to understand the identified message significantly better than male travelers in Missouri and Nevada.

An interesting finding is that the traveler frequency of seeing safety-related messages on DMS was positively correlated with their understanding of the identified message in each site.

Table 12. Odds Ratios and 95 Percent Confidence Limits – Understanding Hypothesis on Understanding of the Listed Message by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	0.8 (0.2, 2.9)	0.8 (0.6, 1.1)	1.0 (0.6, 1.4)	0.5 (0.2, 0.9)
TravelerType 1 vs 3	4.5 (1.7, 11.9)	0.8 (0.6, 1.2)	1.0 (0.6, 1.6)	0.7 (0.4, 1.3)
TravelerType 2 vs 3	5.4 (1.7, 17.0)	1.0 (0.7, 1.4)	1.1 (0.6, 1.7)	1.6 (0.8, 3.1)
Age 1 vs 2	1.2 (0.6, 2.5)	1.5 (1.2, 2.0)	1.3 (0.9, 1.8)	0.8 (0.6, 1.3)
Gender Female vs Male	5.9 (1.3, 25.8)	1.0 (0.7, 1.3)	1.2 (0.9, 1.7)	2.6 (1.5, 4.3)
Round R1 vs R2	0.9 (0.4, 2.0)	19.2 (10.4, 35.4)	1.9 (1.4, 2.6)	1.4 (0.9, 2.4)
Round R1 vs R3		13.8 (7.5, 25.4)		0.7 (0.5, 1.1)
Round R2 vs R3		0.7 (0.6, 0.9)		0.5 (0.3, 0.8)
DMSFrequency 1 vs 2	0.4 (0.1, 0.9)	0.7 (0.5, 0.9)	0.6 (0.4, 1.0)	0.5 (0.3, 0.9)
DMSFrequency 1 vs 3	0.2 (0.1, 0.6)	0.8 (0.5, 1.1)	0.6 (0.4, 0.9)	0.5 (0.3, 0.9)
DMSFrequency 2 vs 3	0.6 (0.2, 1.5)	1.2 (0.8, 1.6)	0.9 (0.6, 1.4)	1.0 (0.6, 1.9)
R1 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	CLICK IT OR TICKET	MOVE OVER FOR HIGHWAY WORKERS	It's a Passing Lane…Not a Cruising Lane
R2 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES	DON'T DRIVE DRUNK, ALCOHOL LAWS ENFORCED	It's No Trick, Seatbelts Are a Treat
R3 Specified Message		WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES		All Buckled, All Seats, All the Time

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

Do you agree that the identified message is understandable?

Site by Site

Participants were asked their agreement on whether the identified safety message currently being displayed on the corridor was understandable. Note that the messages presented for this question for each survey round were the same messages as the previous Understanding Hypotheses question. About 92 percent of travelers agreed or strongly agreed that the identified message was understandable, as shown in Table 13 and Figure 13. Missouri had a relatively lower percentage of travelers who agreed or strongly agreed with the statement. When participant responses to this question were compared with those in the previous question (interpretation of the identified DMS), it was found that although a very high percentage of participants considered the identified DMS understandable, a relatively smaller percentage of participants interpreted the message correctly.

Table 13. Number of Survey Participants per Corridor, and Percentage on Their Agreement on Whether the Message is Understandable.

State	Round	Number and Percentage of Survey Participants: Strongly Disagree	Number and Percentage of Survey Participants: Disagree	Number and Percentage of Survey Participants: Neutral	Number and Percentage of Survey Participants: Agree	Number and Percentage of Survey Participants: Strongly Agree	Number and Percentage of Survey Participants: Total
Nevada	R1	3%	1%	4%	17%	75%	201
Nevada	R2	2%	0%	1%	42%	54%	92
Minnesota/Wisconsin	R1	3%	1%	2%	27%	67%	158
Minnesota/Wisconsin	R2	3%	0%	3%	35%	59%	233
Minnesota/Wisconsin	R3	3%	1%	3%	29%	64%	286
Kansas	R1	5%	1%	3%	29%	62%	170
Kansas	R2	5%	1%	1%	21%	71%	216
Missouri	R1	4%	0%	4%	33%	58%	178
Missouri	R2	3%	1%	8%	40%	48%	102
Missouri	R3	4%	3%	6%	34%	53%	280
All Participants		68 (3%)	22 (1%)	71 (4%)	570 (30%)	1185 (62%)	1916

Note: 21 participants did not provide inputs.

A binary logistic model was fit to the data with the probability of travelers agreeing or strongly agreeing that the message was understandable as the response and traveler type, age, gender, round, and frequency of seeing safety-related message during general travels as the predictors, as shown in Table 14 and Figure C-9 through Figure C-12 in Appendix C. In both Kansas and Nevada, infrequent travelers were more likely than frequent travelers or truckers to consider the message as understandable.

Table 14. Odds Ratios and 95 Percent Confidence Limits – Understanding Hypothesis on Whether the Message is Understandable by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	2.6 (0.9, 7.3)	1.1 (0.6, 2.0)	2.3 (1.2, 4.5)	1.0 (0.6, 1.7)
TravelerType 1 vs 3	4.6 (1.4, 14.9)	0.8 (0.4, 1.5)	1.3 (0.6, 2.7)	0.8 (0.5, 1.3)
TravelerType 2 vs 3	1.8 (0.8, 4.3)	0.7 (0.4, 1.2)	0.6 (0.3, 1.1)	0.8 (0.5, 1.4)
Age 1 vs 2	5.5 (2.3, 13.1)	0.4 (0.2, 0.6)	0.4 (0.2, 0.7)	0.6 (0.4, 0.9)
Gender Female vs Male	0.4 (0.2, 0.9)	2.0 (1.1, 3.6)	2.0 (1.0, 4.0)	1.0 (0.7, 1.5)
Round R1 vs R2	0.4 (0.2, 1.0)	1.3 (0.7, 2.3)	0.8 (0.5, 1.4)	1.4 (0.8, 2.5)
Round R1 vs R3		1.2 (0.6, 2.1)		1.6 (1.0, 2.5)
Round R2 vs R3		0.9 (0.6, 1.5)		1.1 (0.7, 1.9)
DMSFrequency 1 vs 2	0.8 (0.3, 2.4)	0.7 (0.4, 1.4)	0.8 (0.4, 1.7)	0.8 (0.5, 1.2)
DMSFrequency 1 vs 3	1.1 (0.4, 3.1)	0.8 (0.4, 1.5)	1.1 (0.6, 2.3)	0.6 (0.3, 0.9)
DMSFrequency 2 vs 3	1.3 (0.6, 3.1)	1.1 (0.6, 1.9)	1.4 (0.7, 2.8)	0.7 (0.4, 1.2)
R1 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	CLICK IT OR TICKET	MOVE OVER FOR HIGHWAY WORKERS	It's a Passing Lane…Not a Cruising Lane
R2 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES	DON'T DRIVE DRUNK, ALCOHOL LAWS ENFORCED	It's No Trick, Seatbelts Are a Treat
R3 Specified Message		WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES		All Buckled, All Seats, All the Time

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

Messages at All Sites

Survey respondents were presented a series of PSA messages that had been displayed in other survey corridors (e.g., Kansas respondents saw PSA messages that had been displayed in Minnesota/Wisconsin and Nevada), as well as a weather message. Findings show that over 96 percent of all respondents found all four of the messages to be understandable. Participant responses in Figure 14 are presented so that they can be matched in the same category across sites. Note for Figure 14 that invalid means that conflicting responses were selected (i.e., selected both "None of these" and one of the messages); Messages from other sites means the respondent selected at least one message displayed at the other sites; Winter Weather means the respondent selected the winter weather message only; and understand all/none of these is as stated.

Evaluation of Behavior Change

• Hypothesis: The display of a PSA on a DMS does not cause traffic to slow down or other congestion.
  • Question: Have these messages ever caused you to slow down?
• Hypothesis: The contents of the PSA cause a change in behavior by the travelers (e.g., more aware, looking for license plates from an AMBER alert message, etc.).
  • Question: After seeing the messages did you do anything differently?
  • Question: Has seeing one of these messages ever caused you to change your driving?

General – Have these messages ever caused you to slow down?

These general questions were not related to site-specific messages. In other words, the same question was asked in all sites and during all survey rounds and no specific messages were referenced. Similar to the previous question, a smaller percentage (less than 26 percent) of travelers thought the safety-related DMS messages caused them or other travelers to slow down.

Table 15. Have these DMS ever Caused You to Slow Down?

State	Round	Number and Percentage of Survey Participants: Caused to Slow Down	Number and Percentage of Survey Participants: No Change	Number and Percentage of Survey Participants: Invalid	Number and Percentage of Survey Participants: Number of Participants
Nevada	R1	22%	77%	0%	204
Nevada	R2	26%	72%	2%	93
Minnesota/Wisconsin	R1	18%	83%	0%	160
Minnesota/Wisconsin	R2	14%	86%	0%	233
Minnesota/Wisconsin	R3	18%	82%	0%	289
Kansas	R1	26%	72%	2%	177
Kansas	R2	18%	82%	0%	216
Missouri	R1	21%	76%	3%	181
Missouri	R2	14%	86%	0%	102
Missouri	R3	13%	87%	0%	282
All Participants		354 (18%)	1569 (81%)	14 (1%)	1937

A binary logistic model was fit to the data with the probability of causing them to slow down as the response and traveler type, age, gender, round, and frequency of seeing safety-related message during general travels as the predictors, as shown in Table 16 and Figure C-13 through Figure C-16 in Appendix C. In Minnesota/Wisconsin and Nevada, infrequent travelers were significantly less likely to respond that the safety-related DMS messages cause them to slow down to read the message than frequent travelers and truckers. No statistically significant differences were found in Kansas or Missouri.

In Nevada, female travelers were more likely to think the DMS messages would cause traffic to slow down. In Minnesota/Wisconsin and Missouri, travelers who observed safety-related DMS messages with lower frequency were less likely to think the DMS messages would cause them to slow down. These results may reflect geographic differences in driving behavior.

Table 16. Odds Ratios and 95 Percent Confidence Limits – Behavior Hypothesis on whether Safety-Related DMS Cause Drivers to Slow Down by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	0.7 (0.4, 1.2)	0.6 (0.4, 1.0)	0.7 (0.4, 1.0)	1.5 (1.0, 2.5)
TravelerType 1 vs 3	0.4 (0.2, 0.8)	0.5 (0.3, 0.8)	0.9 (0.5, 1.5)	1.3 (0.9, 2.1)
TravelerType 2 vs 3	0.6 (0.4, 1.0)	0.8 (0.5, 1.1)	1.3 (0.8, 2.2)	0.9 (0.6, 1.4)
Age 1 vs 2	0.7 (0.5, 1.1)	1.3 (0.9, 1.7)	1.1 (0.8, 1.6)	1.3 (0.9, 1.8)
Gender Female vs Male	1.8 (1.2, 2.9)	1.3 (0.9, 1.8)	1.0 (0.7, 1.4)	0.8 (0.5, 1.2)
Round R1 vs R2	0.8 (0.5, 1.1)	1.4 (0.9, 2.0)	1.7 (1.2, 2.4)	1.8 (1.1, 2.8)
Round R1 vs R3		1.1 (0.7, 1.5)		1.8 (1.2, 2.5)
Round R2 vs R3		0.8 (0.6, 1.1)		1.0 (0.6, 1.6)
DMSFrequency 1 vs 2	0.8 (0.5, 1.5)	0.6 (0.4, 1.0)	0.6 (0.4, 1.0)	0.4 (0.3, 0.6)
DMSFrequency 1 vs 3	0.7 (0.4, 1.3)	0.7 (0.4, 1.1)	0.7 (0.4, 1.1)	0.6 (0.4, 0.9)
DMSFrequency 2 vs 3	0.9 (0.5, 1.4)	1.1 (0.8, 1.6)	1.0 (0.7, 1.6)	1.4 (1.0, 2.1)

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1

After seeing the identified message did you do anything differently?

Survey participants were asked to report whether they did anything differently immediately after seeing the safety messages currently being displayed in the corridor. The analysis on this question is to understand the impact of PSAs on traveler behavior. Note, however, that changes in behavior were expected be relatively low, given high compliance rates with the safety message, e.g., seat belt usage. As shown in Table 17 and Figure 16, 77 percent of travelers indicated that they did not do anything differently after seeing the identified message. In a follow-up question, most of these respondents said they did not change their behavior because they were already driving safely. In most surveys less than 30 percent of travelers indicated their behavior change after seeing the message, with Minnesota/Wisconsin Round 1 ("EXTRA SEAT BELT PATROLS NOW, CLICK IT OR TICKET" and "BUCKLE UP, __ TRAFFIC DEATHS THIS YEAR") having the smallest percentage at 9 percent. Kansas Round 1 survey had the highest percentage (39%) of drivers reporting any behavior change after seeing the identified message ("MOVE OVER FOR HIGHWAY WORKERS" and "MOVE OVER FOR EMERGENCY VEHICLES").

Table 17. Responses to "Did You Do Anything Differently?" by Site.

State	Round	Number and Percentage of Survey Participants: No	Number and Percentage of Survey Participants: Yes	Number and Percentage of Survey Participants: Number of Participants
Nevada	R1	77%	23%	204
Nevada	R2	76%	24%	93
Minnesota/Wisconsin	R1	91%	9%	160
Minnesota/Wisconsin	R2	77%	23%	233
Minnesota/Wisconsin	R3	74%	26%	289
Kansas	R1	61%	39%	177
Kansas	R2	82%	18%	216
Missouri	R1	71%	29%	181
Missouri	R2	84%	16%	102
Missouri	R3	83%	17%	282
All Participants		1500 (77%)	437 (23%)	1937

Models were structured to investigate the probability of travelers doing things differently after seeing the identified message. It was found that infrequent travelers were significantly less likely to change their driving activity than frequent travelers and truckers in both Kansas and Nevada, as shown in Table 18 and Figure C-17 through Figure C-20 in Appendix C. However, no statistically significant differences were found in Minnesota/Wisconsin or Missouri. Younger people were more likely to do things differently than older people in Kansas and Missouri. This could reflect relatively higher traveler compliance with the subject of the safety messages being shown on certain corridors or by older drivers. Infrequent travelers on a certain corridor may also drive more and be exposed to safety messages in other areas that have helped to encourage safer driving behavior. It was found that for each site-specific model, the odds ratios were not significant only between rounds that had a same information type (i.e., seatbelt).

Table 18. Odds Ratios and 95 Percent Confidence Limits – Behavior Hypothesis on Drivers Doing Anything Differently After Seeing the Message by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	0.6 (0.4, 1.1)	0.8 (0.5, 1.1)	0.6 (0.4, 1.0)	1.0 (0.6, 1.5)
TravelerType 1 vs 3	0.5 (0.3, 0.9)	0.9 (0.6, 1.4)	0.4 (0.3, 0.6)	1.1 (0.7, 1.6)
TravelerType 2 vs 3	0.8 (0.4, 1.3)	1.2 (0.8, 1.7)	0.6 (0.4, 1.0)	1.1 (0.7, 1.7)
Age 1 vs 2	1.0 (0.7, 1.6)	1.3 (1.0, 1.7)	1.9 (1.3, 2.7)	1.4 (1.0, 2.0)
Gender Female vs Male	2.2 (1.4, 3.5)	0.9 (0.7, 1.3)	1.2 (0.8, 1.7)	0.6 (0.4, 0.8)
Round R1 vs R2	0.9 (0.6, 1.4)	0.4 (0.2, 0.6)	3.0 (2.1, 4.2)	2.1 (1.3, 3.3)
Round R1 vs R3		0.3 (0.2, 0.5)		1.9 (1.3, 2.6)
Round R2 vs R3		0.9 (0.7, 1.2)		0.9 (0.6, 1.4)
DMSFrequency 1 vs 2	0.6 (0.3, 1.0)	0.9 (0.6, 1.3)	1.3 (0.8, 2.0)	0.7 (0.5, 1.0)
DMSFrequency 1 vs 3	1.4 (0.8, 2.6)	0.7 (0.5, 1.1)	1.1 (0.7, 1.7)	0.7 (0.5, 1.0)
DMSFrequency 2 vs 3	2.5 (1.5, 4.1)	0.8 (0.6, 1.2)	0.9 (0.6, 1.3)	1.0 (0.7, 1.4)
R1 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	CLICK IT OR TICKET	MOVE OVER FOR HIGHWAY WORKERS	It's a Passing Lane…Not a Cruising Lane
R2 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES	DON'T DRIVE DRUNK, ALCOHOL LAWS ENFORCED	It's No Trick, Seatbelts Are a Treat
R3 Specified Message		WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES		All Buckled, All Seats, All the Time

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

General – Have these messages ever caused changes in your driving behavior?

This is also a general question that was not related to site-specific messages. Between 45 percent and 68 percent of travelers indicated the safety-related DMS messages had caused changes in their driving behavior.

Table 19. Responses to "Have these DMS messages ever caused changes in your driving behavior?" by Site.

State	Round	Number and Percentage of Survey Participants: Caused Changes	Number and Percentage of Survey Participants: No Change	Number and Percentage of Survey Participants: Invalid	Number and Percentage of Survey Participants: Number of Participants
Nevada	R1	55%	43%	2%	204
Nevada	R2	48%	47%	4%	93
Minnesota/Wisconsin	R1	51%	46%	3%	160
Minnesota/Wisconsin	R2	52%	43%	5%	233
Minnesota/Wisconsin	R3	56%	42%	2%	289
Kansas	R1	68%	27%	5%	177
Kansas	R2	48%	46%	6%	216
Missouri	R1	59%	40%	2%	181
Missouri	R2	45%	52%	3%	102
Missouri	R3	49%	50%	1%	282
All Participants		1039 (54%)	835 (43%)	63 (3%)	1937

The probability of the safety-related DMS messages causing driving changes was modeled, and results are presented in Table 20 and Figure C-21 through Figure C-24 in Appendix C. At most sites, except Missouri, infrequent travelers were significantly less likely to change their driving behavior due to the safety-related DMS messages. In Kansas, young travelers and also female travelers were more likely to change their driving because of the DMS messages. Generally, travelers observing DMS less frequently were less likely to change their driving behavior. This may reflect the benefit of a driver seeing specific safety campaign messages more frequently, such that seeing a message advocating for a given topic will eventually lead to a behavior change.

Table 20. Odds Ratios and 95 Percent Confidence Limits – Behavior Hypothesis on Whether DMS Messages Cause Changes in Driving Behavior by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	0.6 (0.4, 1.0)	0.8 (0.6, 1.0)	0.6 (0.4, 0.9)	0.9 (0.6, 1.2)
TravelerType 1 vs 3	0.9 (0.6, 1.5)	1.0 (0.7, 1.4)	0.9 (0.6, 1.4)	1.0 (0.7, 1.4)
TravelerType 2 vs 3	1.5 (0.9, 2.4)	1.3 (1.0, 1.7)	1.5 (0.9, 2.4)	1.1 (0.8, 1.6)
Age 1 vs 2	1.1 (0.8, 1.5)	1.2 (1.0, 1.5)	1.5 (1.1, 2.0)	1.2 (0.9, 1.5)
Gender Female vs Male	1.5 (1.0, 2.3)	1.2 (0.9, 1.6)	1.6 (1.1, 2.2)	0.8 (0.6, 1.1)
Round R1 vs R2	1.3 (0.9, 1.9)	0.9 (0.7, 1.2)	2.6 (1.9, 3.6)	1.7 (1.2, 2.4)
Round R1 vs R3		0.8 (0.6, 1.1)		1.4 (1.1, 1.9)
Round R2 vs R3		0.9 (0.7, 1.2)		0.8 (0.6, 1.2)
DMSFrequency 1 vs 2	0.6 (0.4, 0.9)	1.0 (0.7, 1.4)	1.2 (0.8, 1.8)	0.5 (0.4, 0.7)
DMSFrequency 1 vs 3	1.1 (0.7, 1.8)	0.9 (0.6, 1.2)	0.7 (0.4, 1.0)	0.7 (0.5, 0.9)
DMSFrequency 2 vs 3	1.9 (1.2, 3.0)	0.9 (0.7, 1.1)	0.6 (0.4, 0.9)	1.3 (0.9, 1.8)

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

Evaluation of Traveler Opinions

• Hypothesis: Travelers believe that DMS for safety awareness and PSA messages are appropriate.
  • Question: Do you agree that the message is appropriate?
• Hypothesis: Travelers believe that DMS should only be used for traffic-related messages. Travelers believe that it would be more effective and/or less distracting to motorists to disseminate safety awareness messages and PSAs via other means.
  • Question: What types of message do you think should be displayed on DMS?
• Hypothesis: Travelers believe that it would be more effective and/or less distracting to motorists to disseminate safety awareness messages and PSAs via other means.
  • Question: Which way of communicating safety-related information do you think is best?
• Hypothesis: Travelers perceive a value of safety awareness and PSA messages on DMS.
  • Question: Do you agree that the message raised your awareness of the issue?

Do you agree that the identified message is appropriate?

Site by Site

Travelers were asked their agreement on whether an identified message was appropriate. At least 85 percent of travelers agreed or strongly agreed that the identified message was appropriate, with Minnesota/Wisconsin site travelers resulting in the highest percentage at 93 percent.

Table 21. Number of Survey Participants per Corridor, and Percentage on Their Agreement on Whether the Identified Message is Appropriate.

State	Round	Number and Percentage of Survey Participants: Strongly Disagree	Number and Percentage of Survey Participants: Disagree	Number and Percentage of Survey Participants: Neutral	Number and Percentage of Survey Participants: Agree	Number and Percentage of Survey Participants: Strongly Agree	Number and Percentage of Survey Participants: Total
Nevada	R1	3%	1%	5%	22%	68%	201
Nevada	R2	2%	1%	8%	41%	48%	92
Minnesota/Wisconsin	R1	3%	2%	3%	28%	65%	158
Minnesota/Wisconsin	R2	3%	1%	3%	37%	55%	233
Minnesota/Wisconsin	R3	3%	0%	4%	31%	62%	286
Kansas	R1	4%	2%	5%	29%	59%	170
Kansas	R2	4%	1%	6%	24%	65%	216
Missouri	R1	5%	1%	3%	34%	57%	178
Missouri	R2	1%	1%	8%	47%	43%	102
Missouri	R3	4%	3%	8%	33%	52%	280
All Participants		66 (3%)	25 (1%)	98 (5%)	607 (32%)	1120 (58%)	1916

Note: 21 participants did not provide inputs.

A binary logistic model was fit to the data with the probability of travelers agreeing or strongly agreeing that the message was appropriate as the response and traveler type, age, gender, round, and frequency of seeing safety-related message during general travels as the predictors, and results are presented in Table 22 and Figure C-25 through Figure C-28 in Appendix C.

No statistically significant differences were observed in terms of traveler type. Younger travelers were significantly less likely to consider the messages to be appropriate than older travelers in Kansas, Minnesota/Wisconsin and Missouri, while the opposite was found in Nevada.

Table 22. Odds Ratios and 95 Percent Confidence Limits – Opinions Hypothesis on Agreement that the Identified Message is Appropriate by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	1.5 (0.5, 4.6)	1.1 (0.5, 2.5)	1.4 (0.6, 3.1)	0.6 (0.2, 1.3)
TravelerType 1 vs 3	2.1 (0.6, 7.2)	1.2 (0.5, 3.0)	0.7 (0.3, 1.7)	0.8 (0.4, 1.7)
TravelerType 2 vs 3	1.4 (0.5, 3.9)	1.1 (0.5, 2.4)	0.5 (0.2, 1.2)	1.5 (0.6, 3.6)
Age 1 vs 2	3.0 (1.2, 7.2)	0.5 (0.3, 1.0)	0.4 (0.2, 0.8)	0.5 (0.3, 0.9)
Gender Female vs Male	1.1 (0.4, 2.9)	1.1 (0.5, 2.3)	2.5 (1.1, 5.7)	0.8 (0.5, 1.5)
Round R1 vs R2	1.4 (0.6, 3.1)	1.0 (0.5, 2.2)	1.1 (0.6, 2.1)	1.1 (0.5, 2.6)
Round R1 vs R3		0.8 (0.4, 1.7)		1.7 (0.9, 3.2)
Round R2 vs R3		0.8 (0.4, 1.6)		1.5 (0.7, 3.2)
DMSFrequency 1 vs 2	1.5 (0.5, 4.8)	0.6 (0.3, 1.5)	0.8 (0.3, 1.9)	0.6 (0.3, 1.1)
DMSFrequency 1 vs 3	1.3 (0.4, 4.4)	0.9 (0.4, 2.0)	1.0 (0.4, 2.3)	0.5 (0.3, 1.1)
DMSFrequency 2 vs 3	0.9 (0.4, 2.2)	1.4 (0.7, 3.1)	1.2 (0.5, 2.9)	1.0 (0.5, 2.1)
R1 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	CLICK IT OR TICKET	MOVE OVER FOR HIGHWAY WORKERS	It's a Passing Lane…Not a Cruising Lane
R2 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES	DON'T DRIVE DRUNK, ALCOHOL LAWS ENFORCED	It's No Trick, Seatbelts Are a Treat
R3 Specified Message		WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES		All Buckled, All Seats, All the Time

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

Messages at All Sites

Survey respondents were presented a series of PSA messages that had been displayed in other survey corridors (e.g., Kansas respondents saw PSA messages that had been displayed in Minnesota/Wisconsin and Nevada), as well as a weather message. Findings show that over 90 percent of all respondents found all four of the messages to be appropriate. Participant responses in Figure 19 are presented so that they can be matched in the same category across sites. Note for Figure 19 that invalid means that conflicting responses were selected (i.e., selected both "None of these" and one of the messages); Messages from other sites means the respondent selected at least one message displayed at the other sites; Winter Weather means the respondent selected the winter weather message only; and Understand all/none of these is as stated.

Do you agree that the identified message raised your awareness of the issue?

Site by Site

When asked whether the identified message raised their awareness of the issue, at least 63 percent of travelers agreed or strongly agreed. The Minnesota/Wisconsin Round 2 survey had the highest percentage at 84 percent, while Missouri Round 3 had the smallest percentage at 63 percent.

Table 23. Number of Survey Participants per Corridor, and Percentage on Their Agreement on Whether the Identified Message Raised their Awareness of the Issue.

State	Round	Number and Percentage of Survey Participants: Strongly Disagree	Number and Percentage of Survey Participants: Disagree	Number and Percentage of Survey Participants: Neutral	Number and Percentage of Survey Participants: Agree	Number and Percentage of Survey Participants: Strongly Agree	Number and Percentage of Survey Participants: Total
Nevada	R1	5%	2%	19%	32%	41%	201
Nevada	R2	3%	5%	24%	34%	34%	92
Minnesota/Wisconsin	R1	3%	6%	25%	31%	34%	158
Minnesota/Wisconsin	R2	3%	2%	11%	37%	47%	233
Minnesota/Wisconsin	R3	4%	2%	14%	37%	43%	286
Kansas	R1	5%	3%	16%	32%	44%	170
Kansas	R2	6%	6%	23%	25%	41%	216
Missouri	R1	3%	6%	21%	35%	34%	178
Missouri	R2	2%	7%	26%	33%	31%	102
Missouri	R3	5%	6%	25%	28%	35%	280
All Participants		81 (4%)	83 (4%)	376 (20%)	621 (32%)	755 (39%)	1916

Note: 21 participants did not provide inputs.

As shown in Table 24 and Figure C-29 through Figure C-32 in Appendix C, the logistic regression analysis about whether the message raised traveler awareness of the issue found no significant difference by traveler type; only in Kansas was a significant difference found due to gender. Also in Kansas, travelers seeing DMS frequently were observed to be significantly more likely to think the messages raise their awareness of the issue.

Table 24. Odds Ratios and 95 Percent Confidence Limits – Opinions Hypothesis that the Identified Message Raised their Awareness of the Issue by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	1.2 (0.6, 2.6)	0.7 (0.4, 1.1)	1.4 (0.8, 2.4)	0.6 (0.4, 1.1)
TravelerType 1 vs 3	1.6 (0.7, 3.6)	0.8 (0.4, 1.4)	0.9 (0.5, 1.7)	1.0 (0.6, 1.6)
TravelerType 2 vs 3	1.3 (0.7, 2.7)	1.2 (0.7, 2.0)	0.7 (0.3, 1.3)	1.5 (0.9, 2.6)
Age 1 vs 2	1.5 (0.9, 2.6)	0.8 (0.5, 1.2)	0.8 (0.5, 1.3)	0.9 (0.6, 1.4)
Gender Female vs Male	0.9 (0.5, 1.7)	1.3 (0.8, 2.0)	1.7 (1.0, 2.9)	1.4 (0.9, 2.1)
Round R1 vs R2	1.4 (0.8, 2.5)	0.4 (0.2, 0.6)	1.8 (1.1, 2.9)	1.2 (0.7, 2.1)
Round R1 vs R3		0.5 (0.3, 0.7)		1.3 (0.9, 1.9)
Round R2 vs R3		1.2 (0.8, 1.9)		1.1 (0.7, 1.7)
DMSFrequency 1 vs 2	0.6 (0.3, 1.3)	1.2 (0.7, 2.1)	0.5 (0.2, 0.9)	0.7 (0.4, 1.1)
DMSFrequency 1 vs 3	1.2 (0.6, 2.5)	1.0 (0.6, 1.7)	0.9 (0.5, 1.7)	0.8 (0.5, 1.2)
DMSFrequency 2 vs 3	1.9 (1.0, 3.9)	0.8 (0.5, 1.3)	2.0 (1.1, 3.7)	1.2 (0.7, 1.9)
R1 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	CLICK IT OR TICKET	MOVE OVER FOR HIGHWAY WORKERS	It's a Passing Lane…Not a Cruising Lane
R2 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES	DON'T DRIVE DRUNK, ALCOHOL LAWS ENFORCED	It's No Trick, Seatbelts Are a Treat
R3 Specified Message		WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES		All Buckled, All Seats, All the Time

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

Messages at All Sites

Survey respondents were presented a series of PSA messages that had been displayed in other survey corridors (e.g., Kansas respondents saw PSA messages that had been displayed in Minnesota/Wisconsin and Nevada), as well as a weather message. Findings show that the majority of respondents found all messages to raise their awareness about an issue. Participant responses in Figure 21 are presented so that they can be matched in the same category across sites. Note for Figure 21 that invalid means that conflicting responses were selected (i.e., selected both "None of these" and one of the messages); Messages from other sites means the respondent selected at least one message displayed at the other sites; Winter Weather means the respondent selected the winter weather message only; and Understand all/none of these is as stated.

Displaying safety campaign messages too frequently

Across all four sites, regarding the specific safety campaign messages being shown in the survey corridor 15.0 percent agreed or strongly agreed that the message was displayed too often. However, 24.7 percent agreed or strongly agreed that they were more likely to stop reading DMS after seeing this message multiple times. The responses for all survey rounds for these two questions are depicted in Figure 22 and Figure 23, respectively.

Which way of communicating safety-related information do you think is best?

Most travelers considered DMS as the best way to communicate safety-related information, followed by static signs. Given that travelers were taking a survey asking primarily about DMS, there may have been some bias toward this response.

Table 25. Number of Survey Participants per Corridor, and Percentage on the Best Way to Communicate Safety-related Information.

State	Round	Number and Percentage of Survey Participants: DMS	Number and Percentage of Survey Participants: Online Ad./ Email	Number and Percentage of Survey Participants: Printed Ad.	Number and Percentage of Survey Participants: Radio/TV Ad.	Number and Percentage of Survey Participants: Static Signs	Number and Percentage of Survey Participants: Total
Nevada	R1	72%	3%	0%	5%	21%	199
Nevada	R2	74%	0%	0%	8%	18%	92
Minnesota/Wisconsin	R1	65%	1%	2%	6%	26%	157
Minnesota/Wisconsin	R2	73%	0%	0%	7%	19%	233
Minnesota/Wisconsin	R3	78%	1%	1%	5%	15%	286
Kansas	R1	75%	2%	0%	5%	18%	169
Kansas	R2	71%	1%	0%	4%	25%	216
Missouri	R1	79%	4%	1%	2%	14%	177
Missouri	R2	64%	3%	1%	5%	27%	101
Missouri	R3	75%	1%	1%	5%	19%	280
All Participants		1401 (73%)	31 (2%)	12 (1%)	93 (5%)	373 (19%)	1910

Note: 27 participants did not provide inputs.

The probability of travelers considering DMS as the best communication of safety-related information was modeled, with results presented in Table 26 and Figure C-33 through Figure C-36 in Appendix C. Only in Minnesota/Wisconsin were significant impacts by traveler type observed: infrequent travelers had a significantly higher probability of thinking DMS was the best way to communicate safety-related information than truckers.

Table 26. Odds Ratios and 95 Percent Confidence Limits – Opinions Hypothesis on the Best Way to Communicate Safety-related Information by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	1.0 (0.5, 2.2)	1.5 (1.0, 2.5)	0.9 (0.5, 1.6)	0.8 (0.4, 1.4)
TravelerType 1 vs 3	1.4 (0.6, 3.0)	1.8 (1.1, 3.2)	0.8 (0.4, 1.6)	0.9 (0.5, 1.4)
TravelerType 2 vs 3	1.3 (0.7, 2.7)	1.2 (0.8, 1.9)	0.9 (0.5, 1.8)	1.1 (0.6, 2.1)
Age 1 vs 2	1.4 (0.8, 2.4)	0.8 (0.5, 1.1)	0.8 (0.5, 1.2)	0.8 (0.6, 1.3)
Gender Female vs Male	1.5 (0.8, 2.9)	1.1 (0.7, 1.7)	1.3 (0.8, 2.1)	1.3 (0.9, 2.1)
Round R1 vs R2	0.9 (0.5, 1.7)	0.7 (0.4, 1.0)	1.3 (0.8, 2.0)	2.0 (1.2, 3.5)
Round R1 vs R3		0.5 (0.3, 0.7)		1.3 (0.8, 2.1)
Round R2 vs R3		0.7 (0.5, 1.1)		0.7 (0.4, 1.1)
DMSFrequency 1 vs 2	1.0 (0.5, 2.2)	0.7 (0.4, 1.2)	1.3 (0.7, 2.3)	1.0 (0.6, 1.7)
DMSFrequency 1 vs 3	1.1 (0.5, 2.3)	0.7 (0.4, 1.2)	0.9 (0.5, 1.7)	0.7 (0.4, 1.2)
DMSFrequency 2 vs 3	1.1 (0.5, 2.1)	1.0 (0.6, 1.5)	0.7 (0.4, 1.3)	0.7 (0.4, 1.1)
R1 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	CLICK IT OR TICKET	MOVE OVER FOR HIGHWAY WORKERS	It's a Passing Lane…Not a Cruising Lane
R2 Specified Message	OUR GOAL IS ZERO FATALITIES ON NEVADA ROADS	WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES	DON'T DRIVE DRUNK, ALCOHOL LAWS ENFORCED	It's No Trick, Seatbelts Are a Treat
R3 Specified Message		WI REMINDS YOU TO MOVE OVER FOR EMERGENCY VEHICLES		All Buckled, All Seats, All the Time

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

What types of messages do you think should be displayed on DMS?

The following table shows the percentage of participants who selected specific types of messages that should be displayed on DMS. Note that participants could select multiple message types:

• Traffic messages (e.g., congestion, travel time to a destination, accident), 89 percent;
• Safety-related messages (e.g., seat belts, distracted driving, work zone safety), 73 percent;
• Weather messages (e.g., severe storms, icy conditions, windy conditions), 85 percent;
• Missing person messages (e.g., AMBER alert, silver alert), 68 percent; and
• Other messages (e.g., call 511, special event notice, ozone action day), 33 percent.

The table shows the percentage of participants who picked traffic messages only, or thought the DMS should only display traffic messages. Traffic and weather messages had the highest percentage across the sites. However, a very small percentage (less than 10 percent) of the participants thought DMS should only display traffic messages.

Table 27. Percentage of Survey Participants on Message Types that should be Displayed on DMS.

State	Round	Number and Percentage of Survey Participants: Traffic	Number and Percentage of Survey Participants: Safety-related	Number and Percentage of Survey Participants: Weather	Number and Percentage of Survey Participants: Missing Person	Number and Percentage of Survey Participants: Other	Number and Percentage of Survey Participants: Only Traffic	Number and Percentage of Survey Participants: Total
Nevada	R1	85%	72%	86%	70%	39%	7%	199
Nevada	R2	82%	70%	90%	66%	32%	3%	92
Minnesota/Wisconsin	R1	91%	73%	85%	57%	31%	4%	157
Minnesota/Wisconsin	R2	90%	74%	87%	66%	33%	6%	233
Minnesota/Wisconsin	R3	87%	73%	88%	71%	29%	5%	286
Kansas	R1	89%	78%	89%	69%	29%	4%	169
Kansas	R2	90%	75%	87%	73%	41%	6%	216
Missouri	R1	93%	77%	85%	69%	34%	8%	177
Missouri	R2	86%	75%	79%	65%	38%	7%	101
Missouri	R3	89%	68%	78%	68%	31%	10%	280
Participant Numbers		1693 (89%)	1400 (73%)	1627 (85%)	1301 (68%)	637 (33%)	120 (6%)	1910

Note: 27 participants did not provide inputs.

The probability of travelers thinking DMS should only display traffic message was modeled versus those who think other messages should be displayed, with results presented in Table 28 and Figure C-37 through Figure C-40 in Appendix C. The impact by traveler type was not statistically significant. Younger travelers tended to be more likely to think the DMS should only display traffic messages and these differences were statistically significant in both Kansas and Missouri.

Table 28. Odds Ratios and 95 Percent Confidence Limits – Opinions Hypothesis on Message Types that should be Displayed on DMS by Site.

Label	NV	MN/WI	KS	MO
TravelerType 1 vs 2	1.1 (0.2, 5.2)	1.2 (0.5, 3.2)	3.5 (0.7, 17.0)	1.8 (0.6, 5.1)
TravelerType 1 vs 3	0.6 (0.2, 2.8)	0.8 (0.3, 2.5)	1.4 (0.4, 5.2)	1.0 (0.4, 2.1)
TravelerType 2 vs 3	0.6 (0.1, 2.6)	0.7 (0.3, 1.7)	0.4 (0.1, 2.4)	0.5 (0.2, 1.5)
Age 1 vs 2	1.8 (0.6, 5.4)	1.9 (0.9, 3.9)	3.2 (1.1, 9.6)	2.4 (1.2, 4.6)
Gender Female vs Male	0.4 (0.1, 1.7)	0.6 (0.2, 1.6)	1.0 (0.4, 2.8)	0.8 (0.4, 1.7)
Round R1 vs R2	2.4 (0.6, 8.8)	0.7 (0.3, 1.9)	0.6 (0.2, 1.7)	1.1 (0.4, 2.9)
Round R1 vs R3		1.0 (0.4, 2.6)		0.8 (0.4, 1.6)
Round R2 vs R3		1.4 (0.6, 3.1)		0.7 (0.3, 1.7)
DMSFrequency 1 vs 2	2.2 (0.5, 9.2)	0.6 (0.2, 1.6)	0.9 (0.3, 2.6)	1.7 (0.8, 3.8)
DMSFrequency 1 vs 3	2.4 (0.6, 10.4)	0.9 (0.3, 2.7)	2.6 (0.6, 11.2)	3.0 (1.3, 7.0)
DMSFrequency 2 vs 3	1.1 (0.3, 4.5)	1.6 (0.7, 3.5)	3.1 (0.7, 12.8)	1.7 (0.7, 4.2)

Note: TravelerType 1 = Infrequent, TravelerType 2 = Frequent, TravelerType 3 = Truckers; Age 1 = 16-55, age 2 = Over 55; DMSFrequency 1 = Less than 1 time per month, DMSFrequency 2 = 1-3 times per month, DMSFrequency 3 = One or more times per week.
Value in bold means that the odds ratio is significantly different than 1.

Discussion of Results

Table 29 summarizes specific hypotheses and findings for each of the evaluation areas of awareness, understanding, behavior changes and opinions. Overall, about 77 percent of travelers encountered by the survey team had seen a DMS, while about 79 percent indicated that they had observed at least one of the safety-related messages, which supports the awareness hypothesis. The understanding hypothesis was also supported, as over 79 percent of travelers were able to correctly interpret the presented message. An even higher percentage (92 percent) of respondents agreed or strongly agreed that the message was understandable. In terms of behavior, self-report survey data found that 23 percent of travelers changed their driving behavior after seeing the safety message, which in conjunction with 54 percent saying they have changed their behavior in the past after seeing a safety message, supports the behavior change hypothesis. Given relatively high compliance rates with safety laws and a generally safe traveling population, lower percentages are not surprising. The survey data also indicated that the display of a PSA on a DMS does not seem to cause travelers to slow down to read a message, with 18 percent of respondents reporting that they or others seem to slow down as they pass by these DMS messages. Two of the opinion hypotheses were supported: a high proportion of respondents believed that the safety awareness and PSA message posted at each site was appropriate (90 percent) and raised their awareness of the safety issue (71 percent). A small percentage of respondents (6 percent) indicated that only traffic-related messages should be shown on DMSs and most travelers considered DMS as the best way of communicating safety-related information to the public, which did not support the two related opinions hypotheses.

Further analyses were conducted to examine the differences between traveler types (infrequent travelers, frequent travelers, and truckers). In most sites, infrequent travelers have the highest level of awareness, followed by frequent travelers.

Table 29. Hypotheses and Evaluation Results.

Evaluation Area	Hypotheses	Results	Detail
Awareness	A significant percentage of travelers are aware that safety messages and PSAs are included on DMS	Supported	77% of travelers encountered by the survey team had seen a DMS.
Awareness	A significant percentage of travelers have observed an actual safety message and/or PSA on a DMS	Supported	79% of travelers from the four sites reported that they observed at least one of the safety-related messages. In most sites, infrequent travelers had the highest level of awareness, followed by frequent travelers and then truckers.
Understanding	Drivers can understand the messages on the DMS	Supported	79% of travelers interpreted the message correctly: truckers in Nevada had a significantly lower understanding level than other travelers, and infrequent travelers in Missouri had significantly lower understanding than frequent travelers. 92% of travelers agreed or strongly agreed that the message is understandable; Kansas and Nevada infrequent travelers were more likely than other travelers to consider the message as understandable.
Behavior Changes	The display of a PSA on a DMS does not cause traffic to slow down or other congestion	Partially Supported	18% of travelers thought that they "slow down" or are slowed down by other traffic because of these DMS messages. Minnesota/Wisconsin and Nevada infrequent travelers were significantly less likely to respond that the safety-related DMS messages cause them to slow down to read the message than frequent travelers and truckers. Infrequent travelers at most sites were significantly less likely to change their driving behavior due to the safety-related DMS messages. Young travelers and female travelers in Kansas were more likely to change their driving because of the DMS messages.
Behavior Changes	The contents of the PSA cause a change in behavior by the travelers (e.g., more aware, looking for license plates for AMBER alerts, etc.)	Supported	23% of travelers indicated that they changed their behavior after seeing the specific identified messages in the corridor. 54% of travelers indicated that seeing safety campaign messages on DMSs had caused them to change their driving in the past. Given high compliance rates (e.g., seat belt usage), lower percentages were expected.
Opinions	Travelers believe that DMS for safety awareness and PSA messages are appropriate	Supported	90% of travelers agreed or strongly agreed that the specified safety message posted at each site was appropriate. Younger travelers were significantly less likely to consider the messages to be appropriate than older travelers in Kansas, Minnesota/ Wisconsin and Missouri, while the opposite was found in Nevada.
Opinions	Travelers believe that DMS should only be used for traffic-related messages	Not supported	6% of travelers thought that only transportation-related message should be displayed on DMSs. Impact by traveler type was not statistically significant; younger travelers tended to be more likely to think the DMS should only display traffic message and these differences were statistically significant in both Kansas and Missouri.
Opinions	Travelers believe that it would be more effective and/or less distracting to motorists to disseminate safety awareness messages and PSAs via other means	Not supported	73% of travelers indicated that DMS is the best way of communicating safety-related information. Only in Minnesota/Wisconsin were significant impacts observed: infrequent travelers had a significantly higher probability of thinking DMS was the best way to communicate safety-related information than truckers.
Opinions	Travelers perceive a value of safety awareness and PSA messages on DMS	Supported	71% of travelers agreed or strongly agreed that the specified DMS message at each site raised their awareness of the issue. There was no significant difference by traveler type; only in Kansas was a significant difference found for females and also for travelers seeing DMS frequently to be more likely to think the messages raise their awareness of the issue.

Recommendations

The analysis presented above supports displaying public service announcements and safety messages on DMS in rural areas. Overall, 73 percent of surveyed travelers in rural areas support the use of DMS to display PSAs and safety-related information, and 73 percent think DMS are the best way to communicate that information. About 54 percent of respondents had changed their behavior due to a safety message being posted on DMS, which should enhance overall safety. In addition, few respondents felt that the specified PSAs and safety-related information were displayed too often. As such, this evaluation can generally validate current agency practices in the survey corridors for displaying safety messages and PSAs on rural DMS. However, on rural corridors with higher volumes, agencies may want to examine potential mobility and safety impacts caused by travelers slowing down to read DMS messages, given that a full 18 percent of respondents reported this occurring.

These findings also suggest that displaying safety messages and PSAs more frequently would generally not be detrimental. About 23 percent of survey respondents reported behavior changes after reading the safety message on the DMS, however given high compliance rates with seatbelt use, for example, a relatively low number is not surprising. Even a small percentage of travelers changing their behavior could result in a positive influence on highway safety. About 54 percent of survey respondents indicated that they had changed their behavior in the past after reading a safety message on a DMS. In addition, many travelers who responded that they did not change their behavior anecdotally responded that reading the safety message made them more conscious of driving in a safer manner.

More research is also needed to examine the benefits of displaying catchy messages versus traditional messages. Catchy messages were only displayed in one of the four survey corridors for the duration of the survey in that location, however insufficient data and other bias did not allow for a comprehensive assessment. Anecdotally, catchy messages were commented on by travelers surveyed in other States displaying traditional messages; most remembered those messages in a positive manner. However, catchy messages could also influence the negative comments about DMS being a distraction.