Civil Engineering Reference
In-Depth Information
Table 6.7 Trends in the key
factors determining VMT
growth in time
1960
2000
1. Workers ([
7
], Exhibit 1.6)
- % of population
36.1
45.6
- % male
67.7
53.2
- % female
32.3
46.7
2. Daily trip rate ([
8
], Exhibit A-9)
- Per person
1.9
4.1
- Per worker
2.2
4.5
- Per non-worker
1.7
3.7
3. Ownership of private vehicles ([
9
], Table 1)
- Per person
0.31
0.63
- Per 16+ year old
0.53
0.91
- Per driver
0.70
1.06
6.2.3.1 Increasing Trip Length
The average person trip length in low-density areas is considerably higher than that
in the higher density areas. As shown in Fig.
6.5
the daily VMT per person
increases with decreasing population density from more than 20 miles for the
lowest density to about 2 miles for the highest. This is because car ownership is
greater in low density areas and vehicle trips to and from these areas are longer.
Fig. 6.5 Trip length as a function of population density
Source
Calculated from Reference [
4
],
Table 15.5
