United States Travel Trends
The National Household Travel Survey released the Summary of Travel Trends, 2001 National Travel Survey in 2004 which provided data from the initial survey in 1969 up to the 2001 National Travel Survey. Figure 17 shows the demographic statistics from the NHTS. The data shows a decrease in the number of persons per household, but an increase in the number of vehicles, workers, and licensed drivers per household (11).
Figure 18 indicates an upward trend in the population, the number of civilians employed, and the number of licensed drivers.
The data presented in Figure 19 represents the number of vehicles for every 1000 persons in the United States. The trend is mostly upward. The dips indicate times of recession or war.
The NHTS data points out that the average vehicle trip length has increased from 1969 to 2001. Figure 20 is a graph of this data.
Figure 21 presents the data for the average annual vehicle-miles for each household. Figure 22 shows the data for the average annual vehicle trips. Figure 23 is the data for the average vehicle trip length. The data in these three figures is broken into journey-to-work trips and all the trips combined for each household.
Figure 24 shows that the number of vehicles per household increases along with the number of licensed drivers per household.
Data was collected on the household vehicle trips in the 2001 NHTS. Figures 25, 26, and 27 break down the data into the number of daily vehicle trips, the average vehicle trip length, and the daily miles of vehicle travel for each household.
Figure 28 shows the distribution of vehicle trips by the trip distance for the total vehicle trips and the vehicle trips to work.
Figure 29 shows the time of day that trips are started.
Figures 30, 31, and 32 show the average annual vehicle-miles of travel, vehicle trips, and trip length per household broken down by trip purpose. These results provide some insight into how the vehicles in a household are used.
Figure 33 represents the distribution of workers by the total time of their commute.
Figure 34 is the distribution of vehicles by type in the United States.
Figure 35 is an estimate of the number of electric vehicles in use in the United States for each year from 1995 to 2007.
Figure 36 shows the number of conventional refueling stations for every 1000 cars from 1993 to 2007.