Question

6. You are provided with the following summary tables from a local survey. The households are grouped by income level and household size.

Table 8-1: Numbers of Households in each group

				HH Size
Income Level		1	2	3	4	5+
Under $20,000		38	20	21	35	23
$20,000	~ $39,999	266	257	113	149	72
$40,000	~ $59,999	704	356	1355	1245	82
$60,000	~ $99,999	326	463	1644	1846	164
$100,000	~ $149,000	313	2427	787	448	347
$150,000 and more		52	74	121	173	83

Table 8-2: Total numbers of trip productions by each group

				HH Size
Income Level		1	2	3	4	5+
Under $20,000		38	20	21	35	23
$20,000	~ $39,999	266	257	113	149	72
$40,000	~ $59,999	704	356	1355	1245	82
$60,000	~ $99,999	326	463	1644	1846	164
$100,000	~ $149,000	313	2427	787	448	347
$150,000 and more		52	74	121	173	83

A new modeling area has the following groups of households.

Table 8-3: Numbers of households in each group in the new modeling area

				HH Size
Income Level		1	2	3	4	5+
Under $20,000		4	19	7	30	1
$20,000	~ $39,999	45	53	21	19	2
$40,000	~ $59,999	572	233	937	702	50
$60,000	~ $99,999	179	78	125	1124	47
$100,000	~ $149,000	81	439	577	108	278
$150,000 and more		26	72	44	62	2

Use the cross-classification method to estimate the total number of trip productions by this new area.

Answer 1

Answer

Numbers of Households in each group(table 8.1) and Total numbers of trip productions by each group (table 8.2)is same.

So, the Trip rate would be 1.

Trip rate = Number of trip production / Number of house hold

Applyingg this Trip rate in New model of number of households to estimate the total number of trip productions by this new area.

Estimate the total number of trip productions = Trip rate x Number of households

Income Level		1	2	3	4	5+
Under $20,000		4	19	7	30	1
$20,000	~ $39,999	45	53	21	19	2
$40,000	~ $59,999	572	233	937	702	50
$60,000	~ $99,999	179	78	125	1124	47
$100,000	~ $149,000	81	439	577	108	278
$150,000 and more		26	72	44	62	2