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Cross Classification
The following cross-classification data have been developed for Beaver Dam
Transportation Study Area.
| ($000) |
HH (%) |
Autos/HH (%) |
| Income |
High |
Med |
Low |
0 |
1 |
2 |
3 |
10 |
0 |
30 |
70 |
48 |
48 |
4 |
0 |
20 |
0 |
50 |
50 |
4 |
72 |
24 |
0 |
30 |
10 |
70 |
20 |
2 |
53 |
40 |
5 |
40 |
20 |
75 |
5 |
1 |
32 |
52 |
15 |
50 |
50 |
50 |
0 |
0 |
19 |
56 |
25 |
60 |
70 |
30 |
0 |
0 |
10 |
60 |
30 |
| ($000) |
Trip Rate/Auto |
Trips (%) |
| Income |
0 |
1 |
2 |
3+ |
HBW |
HBO |
NHB. |
| 10 |
2.0 |
6.0 |
11.5 |
17.0 |
38 |
34 |
28 |
| 20 |
2.5 |
7.5 |
12.5 |
17.5 |
38 |
34 |
28 |
| 30 |
4.0 |
9.0 |
14.0 |
19.0 |
35 |
34 |
31 |
| 40 |
5.5 |
10.5 |
15.5 |
20.5 |
27 |
35 |
38 |
| 50 |
7.5 |
12.0 |
17.0 |
22.0 |
20 |
37 |
43 |
| 60 |
8.0 |
13.0 |
18.0 |
23.0 |
16 |
40 |
44 |
Develop the family of cross classification curves and determine the number of trips
produced (by purpose) for a traffic zone containing 500 houses with an average household
income of $35,000. (Use high = 55,000; medium = 25,000; low = 15,000)
[Solution Shown Below]
Solution
The solution to this type of problem is best described through the use of graphs
and tables. The graphs and tables used for this problem are shown below.
 
| Income |
Households (%) |
HH/Zone |
Total
HH |
|
| Low $under $20,000 |
13 |
500 |
65 |
| Medium $20,000-45,000 |
72 |
500 |
360 |
| High $45,000-$60,000 |
15 |
500 |
75 |
|
100 |
|
500 |
| |
| Percentage
of HH owning # vehicles |
Auto
Ownership |
Income |
|
|
Low |
Medium |
High |
|
0 |
26 |
3 |
0 |
1 |
60 |
63 |
15 |
2 |
14 |
32 |
58 |
3+ |
0 |
2 |
27 |
|
100 |
100 |
100 |
|
| Trips per HH per
Income Level and Auto Ownership |
Auto
Ownership |
Income |
|
|
Low |
Medium |
High |
|
0 |
2 |
3 |
7 |
1 |
7 |
8 |
13 |
2 |
12 |
13 |
18 |
3+ |
17 |
18 |
23 |
|
| Number
of HH owning # vehicles |
|
Auto
Ownership |
Income |
|
|
Low |
Medium |
High |
|
0 |
17 |
11 |
0 |
1 |
39 |
227 |
11 |
2 |
9 |
115 |
44 |
3+ |
0 |
7 |
20 |
|
65 |
360 |
75 |
|
| Trips
made by income level |
Auto
Ownership |
Income |
|
|
Low |
Medium |
High |
|
0 |
34 |
32 |
0 |
1 |
273 |
1814 |
146 |
2 |
109 |
1498 |
783 |
3+ |
0 |
130 |
466 |
| |
416 |
3474 |
1395 |
5285 |
|
| Trips
by Trip Purpose % |
| |
Income |
|
|
Low |
Medium |
High |
|
| HBW |
38 |
37 |
18 |
| HBO |
34 |
34 |
38 |
| NHB |
28 |
29 |
44 |
| |
100 |
100 |
100 |
|
| Number
of Trips by Purpose |
|
Income |
|
|
Low |
Medium |
High |
|
| HBW |
158 |
1285 |
251 |
1695 |
| HBO |
141 |
1181 |
530 |
1853 |
| NHB |
116 |
1007 |
614 |
1738 |
Problem adapted from:
Garber, N.J. and Hoel, L.A., Traffic and Highway Engineering, Revised 2nd Edition,
PWS, Pacific Grove, CA. 1999. Page 545
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