# Using Connected Vehicle Data to Evaluate National Trip Trends
## 8 Daily Mean Trip Lengths for Selected States  
Daily trip statistics provide visibility into how day-of-week travel patterns differ across the country as well as by time of year. As a reference, one state from each of the four major time zones in the United States has been selected for the visualizations in this section; however, these graphics can easily be reproduced for any state or another geographic aggregation level of choice (county, census tract, census blockgroup, for example). For the visualizations presented in this section, CV trips are spatially and temporally assigned based on the state they originated from and the date on which they began, respectively. Solid gray vertical lines on each of the graphics in this section represent Sundays for the month of December. About 23 million CV trips were recorded to be originating in Indiana in December 2022, and the corresponding daily mean values of trip length and trip duration are shown in Figure 6a,b, respectively. The highest mean trip length observed for Indiana was 11.76 mi for Christmas Day and the highest mean trip duration observed was 25.47 min for 23 December, one of the days when Indiana was severely impacted by a winter storm event characterized by an arctic cold front [29]. On average, Indiana recorded mean trip lengths of 8.93 mi for HVs, 8.66 mi for ICEVs, and 7.59 mi for EVs. ICEVs were observed to be driven for the longest time on average, with a mean trip duration of 18.82 min for the month. Weekday trip length and trip duration trends are fairly repetitive, while most higher trip lengths are visible over the weekends. Figure 6: Daily Trip Statistics for Indiana (December 2022) **(a)** Mean Estimated Trip Length **(b)** Mean Trip Duration. The state of Texas observed ICEVs being driven the longest in terms of distance and time, both for the month, with mean values of 8.99 mi and 19.62 min, respectively. On a daily fidelity, Christmas Day exhibited the highest mean trip length across all three types of vehicles, at 12.80 mi, 11.90 mi, and 10.65 mi, respectively, for HVs, ICEVs, and EVs. Nearly 114 million CV trips are represented by the daily aggregated graphics for mean trip length and mean trip duration shown in Figure 7.  
Wyoming recorded about 1.7 million CV trips for the month of December, with HVs and ICEVs on average being driven nearly the same distance of about 6.9 mi, with the mean trip length for EVs nearly 2 miles lower at 4.99 mi. The high variation seen in HV trip lengths and trip durations over the month (Figure 8) can be attributed to a low sample size (730 trips). Figure 7: Daily Trip Statistics for Texas (December 2022) (**a**) Mean Estimated Trip Length (**b**) Mean Trip Duration. California observed approximately 75 million CV trips for the month, including about 3 million EV trips and 0.75 million HV trips. On average, mean trip lengths were lower in California than in Indiana and Texas, with mean trip lengths of 7.08 mi, 6.91 mi, and 6.47 mi for HVs, ICEVs, and EVs, respectively. Expectedly, weekday patterns across the month are fairly repetitive, with longer trips in terms of duration and distance seen to be taken on the Sundays of the month, as shown in Figure 9. Across all the days and irrespective of vehicle type, Christmas Day (Sunday 25 December 2022) observed the highest mean trip distance of 8.96 mi, nearly 1.5 miles higher than any other day of the month. Long-distance travel rising on Christmas Day has historically been documented by the American Travel Survey [30], and the CV data analyzed by this study confirms this largely anecdotal and survey-based observation with quantitative statistics. Figure 8: Daily Trip Statistics for Wyoming (December 2022) (**a**) Mean Estimated Trip Length (**b**) Mean Trip Duration. The methodologies and corresponding visualizations demonstrated by this study highlight the versatility and scalability of CV data towards monitoring national trip trends in a cost-, labor-, and time-effective manner to analyze trip trends at the national, state, and local levels.