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Effectiveness of Disseminating Traveler Information on Travel Time Reliability: Implement Plan and Survey Results Report

CHAPTER 7. NORTH COLUMBUS TRANSPORTATION STUDY

The following sections describe in detail the various recruiting rounds of study in Columbus.

SITE DEPLOYMENT TIMELINE

As previously discussed, several rounds of data collection were conducted in Columbus (Rounds 1, 3 and 4). The following sections provide an overview of the timeline for the various rounds of subject recruitment and participation.

North Columbus, Round 1

Invitation postcards were mailed to potential participants in the Columbus study area on April 17, 2015. The baseline survey was opened on April 20. Qualifying participants were notified by email on May 4, invited to download the smartphone application, and given instructions for recording trips and completing trip diary questions. Phase 1 of the travel study began on May 6. On May 15, Phase 1 participants who had completed at least four recorded trips were invited to continue to Phase 2. Phase 2 concluded on June 8, and participants who had completed at least four trips during Phase 2 were invited on June 10 to take the exit survey. Incentives were distributed by email on June 24 to participants who had completed all steps of the study. Table 21 illustrates the timeline for Round 1 of the North Columbus Transportation Study.

Table 21. Timeline of activities for Round 1 of the North Columbus Transportation Study.
North Columbus (Ohio) Transportation Study Weekly Timeline of Activities (Date)
April 2015 May 2015 June 2015
Recruitment postcards mailed 17thgray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell
Potential participants begin taking baseline survey Empty cell 20thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell
Participants assigned to treatment groups Empty cell Empty cell Empty cell 4thgray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell
Phase 1 "Welcome" email sent Empty cell Empty cell Empty cell 4thgray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell
Columbus Phase 1 Empty cell Empty cell Empty cell 6thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell
Phase 2 "Welcome" email sent Empty cell Empty cell Empty cell Empty cell 15thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell
Columbus Phase 2 Empty cell Empty cell Empty cell Empty cell 15thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell
Exit survey invitation sent Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell 10thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period
Exit survey reminder sent Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell 21stgray shaded cell: activity took place during this period
Incentive distribution Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell 24thgray shaded cell: activity took place during this period

North Columbus, Rounds 3 & 4

Additional rounds of recruitment in Columbus were conducted during the fall of 2015 and spring of 2016, similar to the third round of data collection in Houston. These were the second and third rounds of data collection, but were conducted in parallel with and following Houston Round 3 (fall 2015 and winter 2016); therefore, they are nominally described as Rounds 3 and 4 for Columbus as well. The same study corridor (I-71) was used because no alternatives were identified where travel time data could be readily available and quickly processed for dissemination in the study.

Round 3 recruitment efforts began in September 2015, and participants were invited to the baseline survey beginning September 29. Following baseline completion, participants were invited to Phase 1 in weekly batches (similar to the North Houston). Again, batching participants was more efficient for administration purposes and moving participants promptly into the study, while still allowing recruitment to continue. Table 22 illustrates the timeline for Round 3 of data collection in Columbus.

Table 22. Timeline of activities for Round 3 of the North Columbus Transportation Study.
North Columbus (Ohio) Transportation Study Weekly Timeline of Activities (Date)
September 2015 October 2015 November 2015
Outreach recruitment & Prescreening 21stgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell
Baseline survey Empty cell 28thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell
North Columbus Round 3 Phase 1 Empty cell Empty cell Empty cell 12thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell
North Columbus Round 3 Phase 2 Empty cell Empty cell Empty cell Empty cell Empty cell 26thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell
Exit survey Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell 16thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period
Incentive distribution Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell 30thgray shaded cell: activity took place during this period

A final round of recruitment (including an increased incentive offering) was conducted in North Columbus due to low response to Columbus Round 3. Round 4 recruitment efforts began in January 2016, and participants were invited to the baseline survey beginning February 4. Table 23 illustrates the timeline for Round 4 of data collection in Columbus.

Table 23. Timeline of activities for Round 4 of the North Columbus Transportation Study.
North Columbus (Ohio) Transportation Study Weekly Timeline of Activities (Date)
February 2016 March 2016 April 2016
Outreach recruitment & prescreening 1stgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell
Baseline survey 4thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell
North Columbus Round 4 Phase 1 Empty cell 9thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell
North Columbus Round 4 Phase 2 Empty cell Empty cell Empty cell Empty cell 3rdgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell Empty cell
Exit survey Empty cell Empty cell Empty cell Empty cell Empty cell 10thgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period gray shaded cell: activity took place during this period Empty cell Empty cell
Incentive distribution Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell Empty cell 3rdgray shaded cell: activity took place during this period gray shaded cell: activity took place during this period

PARTICIPANT SELECTION AND ASSIGNMENT

The following sections provide a summary of the participation recruitment, selection, and assignment for the Columbus study.

North Columbus, Round 1

For Columbus, the study area was defined as the I-71 freeway between U.S. 36 (north of Columbus) and I-70 (in downtown Columbus). As shown in the map and table on the following pages, the geographic sample frame included thirteen zip code areas adjacent to I-71 between (and just north of) U.S. 36 and I-670. Zip codes south of I-670 were not included because it was assumed residents closer to downtown were less likely to regularly drive on a significant portion of the freeway, particularly in the direction with the most frequent congestion (inbound towards downtown in the morning, outbound away from downtown in the evening).

A sample of 23,900 addresses (approximately 18 percent of the addresses in the selected area) was randomly selected, proportional to the population across the entire area. As previously discussed, this quantity of invitations was planned based on initial predictions about response rates and retention rates throughout the study. The sample included all types of residential mailing addresses (single-family houses, apartments, post office boxes, etc.), but excluded "seasonal" and "vacant" addresses. A list of the zip codes used for the invitations is provided in Table 24, while a map illustrating the locations of these zip codes in the region is shown in Figure 26. Recruitment materials used for the North Columbus region are included in Appendix Q.

Table 24. Columbus sample zip codes.
Zip Code Estimated Number of Households Percent
43240 1,585 1.2
43021 3,371 2.5
43074 4,690 3.5
43211 8,037 5.9
43035 8,489 6.3
43202 9,263 6.8
43085 9,323 6.9
43082 10,837 8.0
43201 11,883 8.8
43214 12,214 9.0
43224 14,838 11.0
43229 19,091 14.1
43081 21,784 16.1
Total 135,405 100

Figure 26. This figure shows a map of the zip codes within the North Columbus Transportation Study region. They are color-coded (i.e., degree of darkness) to signify population counts.

Figure 26. Map. Columbus sample zip codes geography.

North Columbus, Round 3

Additional rounds of recruitment were conducted in Columbus, using the same study corridor (I-71), to obtain additional participants for the overall study. The second round of data collection was conducted during "Round 3" (with a timeline parallel to Round 3 in Houston). Similar to Houston Round 3, Columbus Round 3 participants were recruited through a variety of outreach methods including newspaper articles, local television news spots, and recruiting with local businesses. For an incentive, Columbus Round 3 participants were entered into a drawing for one of several iPads. This incentive structure was used to manage costs and avoid limitations to additional recruitment based on incentive-funding constraints.

North Columbus, Round 4

The final round of recruitment in Columbus occurred shortly after Round 3 concluded. For this round, advertisements were placed in various electronic newsletters distributed to students and staff at the Ohio State University (OSU), which is located within the study corridor. In addition, notices were placed on selected OSU websites (e.g., Off-Campus and Commuter Student Services). Columbus Round 4 participants were offered $100 as an incentive (similar to Houston Round 3), because it was determined that the prize drawing offered for Columbus Round 3 was not effective in encouraging enrollment and participation in the study.

BASELINE SURVEY RESULTS

Table 25 through Table 29 summarize the results of the baseline survey for the Columbus area for all rounds of data collection. Note that all tables include only valid responses, and do not include any responses from participants who were screened out due to infrequent corridor use or lack of a smartphone. Some tables include fewer than 100 percent of qualified participants if the question was skipped by certain participants (for example, participants who reported "never" using the Travel Time Reliability [TTR] information resources in Phase 2 skipped questions about TTR information ratings and satisfaction and instead were asked why they did not use the information). The total number of baseline responses provided in each round in Columbus are shown in Table 25.

Table 25. Number of baseline completions by round, Columbus.
Data Collection Round Count Percent
Round 1 (Spring 2015) 621 76.9
Round 3 (Fall 2015) 70 8.7
Round 4 (Winter 2016) 117 14.5
Total Baseline Participants 808 100

Table 26 summarizes how often Columbus participants traveled on the main highway in the study area. Approximately two-thirds traveled on the highway daily. No participants who qualified and completed the baseline traveled on the highway less than three weekdays per week, because those who did travel infrequently were screened out of the survey.

Table 26. Number of weekdays typically driven on primary freeway (I-71) in study area, Columbus.
Number of weekdays typically driven on primary freeway in study area12* Count Percent
5 weekdays/week 526 65.1
4 weekdays/week 101 12.5
3 weekdays/week 181 22.4
Total Baseline Participants 808 100

12* Participants who traveled less than 3 days/week on the primary freeway were not qualified. [Return to 12*]

Similar to the Houston panel, the majority of Columbus participants were between 25 and 55 years old, though the Columbus panel was slightly more dispersed across age groups (see Table 27).

Table 27. Respondent age, Columbus.
Respondent Age Count Percent
18-24 73 9.0
25-34 219 27.1
35-44 229 28.3
45-54 144 17.8
55-64 115 14.2
65-74 27 3.3
75-84 1 0.1
85 or older 0 0.0
Total Baseline Participants 808 100

Table 28 and Table 29 summarize what kinds of traveler information participants used prior to the study, as well as how they changed their travel behavior. Compared to Houston, fewer participants in Columbus typically use any type of information. Again, smartphone apps were most common, but radio was almost as common for Columbus participants' familiar trips.

Table 28. Types of information sources used at least one day per week, Columbus.
Types of Information Sources13* For Familiar Trips: Count For Familiar Trips: Percent For Unfamiliar Trips: Count For Unfamiliar Trips: Percent
Websites 247 30.6 271 33.5
Smartphone apps 460 56.9 430 53.2
Telephone numbers14* 48 5.9 48 5.9
TV 249 30.8 133 16.5
Radio 428 53.0 212 26.2
Built-in GPS device 51 6.3 57 7.1
Portable GPS device 70 8.7 105 13.0
Other sources 15 1.9 17 2.1
Total Baseline Participants 808 -- 808 --

13* Participants could report using multiple sources. [Return to 13*]
14*eneralized question about telephone information use; may or may not include existing 511 services where applicable or other local services (e.g., a state or city toll-free information number). [Return to 14*]

As shown in Table 29, Columbus participants were less likely to make significant changes such as canceling their trips or completely changing their routes, but were still fairly likely to start their trip earlier or make small route adjustments.

Table 29. Types of travel behavior changes made "sometimes" or "frequently" due to traveler information, Columbus.
Types of Travel Changes15* For Familiar Trips: Count For Familiar Trips: Percent For Unfamiliar Trips: Count For Unfamiliar Trips: Percent
Start trip earlier 514 66.3 482 62.8
Start trip later 193 24.9 173 22.6
Make minor route changes 559 72.1 426 55.5
Change to toll road 20 2.6 25 3.3
Completely change route 256 33.0 237 30.9
Change to public transit 19 2.5 17 2.2
Cancel or postpone trip 46 5.9 75 9.8
Telecommute 48 6.2 31 4.0
Total participants answering 775 -- 767 --

15* Participants could report multiple changes; some participants skipped these questions because they "never" used traveler information. [Return to 15*]

EXIT SURVEY RESULTS

Table 30 through Table 33 summarize the results of the exit survey in Columbus for all rounds of data collection. The total number of exit survey responses collected in each round are shown in Table 30.

Table 30. Number of exit responses by round, Columbus.
Data Collection Round Count Percent
Round 1 (Spring 2015) 125 45.6
Round 3 (Fall 2015) 55 20.1
Round 4 (Winter 2016) 94 34.3
Total Exit Participants 274 100

As with Houston, the distribution of participants across treatment groups remained roughly even through the end of the study (see Table 31).

Table 31. Exit responses by treatment group, Columbus.
Treatment Group Count Percent
Web, Lexicon A 44 16.1
Web, Lexicon B 49 17.9
App, Lexicon A 50 18.2
App, Lexicon B 42 15.3
511, Lexicon A 51 18.6
511, Lexicon B 38 13.9
Total Exit Participants 274 100

More than two thirds of Columbus participants rated the TTR information sources as clear and reliable (see Table 32). Also, compared to Houston, it appears that Columbus participants had slightly higher satisfaction with the TTR information resource (see Table 33). As previouly discussed, the exit survey measured participant perceptions of their activities, information use, and information satisfaction during Phase 2, rather than objectively observed behaviors or outcomes. The questions included attitudinal statements designed to measure participants' satisfaction with various aspects of the TTR information, as shown in the tables below.

Table 32. Travel time reliability information ratings ("somewhat agreed", "agreed", or "strongly agreed"), Columbus.
TTR Ratings Statement16* Count Percent
The Transportation Study Resource was easy to understand 188 78.7
The Transportation Study Resource was reliable 161 67.4
Transportation Study Resource did NOT reduce the amount of travel time I plan for my trips 171 71.5
Overall, the Transportation Study Resource was useful 118 49.4
The Transportation Study Resource helped me reduce my travel time 49 20.5
The Transportation Study Resource helped me avoid congestion 63 26.4
The Transportation Study Resource reduced the stress of my trip 57 23.8
The Transportation Study Resource helped me plan my trips 82 34.3
Total participants answering 239 --

16* Participants could agree with multiple statements; some participants skipped these questions because they "never" used TTR information. [Return to 16*]

Table 33. Travel time reliability lexicon satisfaction ("somewhat satisfied", "satisfied", or "very satisfied"), Columbus.
TTR Lexicon Category17* Count Percent
Estimated/ approximate travel time 169 70.7
Extra time/ recommended cushion 129 54.0
Recommended/ suggested departure time 115 48.1
Total travel time estimate for most/majority of the time 160 66.9
Total participants answering 239 --

17* Participants could agree with multiple statements; some participants skipped these questions because they "never" used TTR information. [Return to 17*]

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