Case Study:

Montgomery County, Maryland

Application

Comparison of Alternatives

Figure 4 illustrates the transit county-wide accessibility index to households and jobs under each alternative network is illustrated below. Table 2 shows how the county's accessibility measures compare among the various alternatives. Table 2 compares the transit and auto accessibility measures, and also shows average work-trip travel times under each alternative. Table 2 compares the transit and auto accessibility measures, and also shows average work-trip travel times under each alternative.

Figure 4. Transit County-Wide Accessibility Index

Fig. 4 Transit County-Wide Accessibility Index

Source: Maryland-National Capital & Planning Commission.

Table 2. Measures of Effectiveness

	1998 Base	2020 Base	2020 Comb. A	2020 Comb. B	2020 Comb. C	2020 Comb. D	2020 Rec. Plan
*Transit Accessibility*
County-wide to Households (000s)	98	104	116	129	138	146	137
County-wide to Jobs (000s)	182	194	217	240	267	281	254
Activity Center to Households (000s)	155	162	183	204	250	261	229
Average Travel Time (min.)	55.9	60.4	53.8	48.2	47.6	45.9	46.8
*Auto Accessibility*
County-wide to Households (000s)	546	647	667	722	653	726	748
County-wide to Jobs (000s)	423	1,134	1,174	1,189	1,107	1,235	1,286
Activity Center to Households (000s)	195	658	672	741	669	740	771
Average Travel Time (min.)	26.0	35.2	33.8	32.6	33.9	32.6	31.1

Source: Maryland-National Capital Park & Planning Commission (1999).

Planning staff also took the measures a step further and compared accessibility to the cost of each alternative to develop a "cost efficiency index." To do this, the change in accessibility was first divided by the cost of the alternative. To develop the efficiency index, the change per unit cost for the best alternative was set at 100, and the change per cost for each other alternative was rated relative to 100 (Table 3).

Table 3: Cost Efficiency Index

Change from Base Divided by Capital Cost						Efficiency Index
	2020 Comb. A	2020 Comb. B	2020 Comb. C	2020 Comb. D	2020 Rec. Plan	2020 Comb A	2020 Comb. B	2020 Comb. C	2020 Comb. D.	2020 Rec. Plan
*Transit Accessibility*
County-wide to Households (000s)	9.06	9.59	10.22	9.70	11.26	80	85	91	86	100
County-wide to Job (000s)	17.36	17.64	21.95	17.09	20.47	79	80	100	78	93
*Auto Accessibility*
County-wide to Households (000s)	15.09	28.77	1.80	18.24	34.46	44	83	5	53	100
County-wide to Jobs (000s)	30.19	21.10	(8.12)	23.32	34.46	88	61	(24)	68	100

Source: Maryland-National Capital Park & Planning Commission (1999).

Some of the conclusions the county drew from the evaluation include:

More expensive combination networks provide superior performance than lower cost networks, as might be expected.
Based on all of the accessibility measures, the recommended plan is the most cost-effective means to increase automobile accessibility.
While generally not providing the greatest transit accessibility improvements, the recommended plan did well on these measures - particularly on the destination accessibility measures - relative to most other alternatives. The transit measures alone did not clearly favor one alternative over another.

Overall, the county found the combination of mobility and accessibility measures to be helpful in comparing alternatives and developing a recommended plan (Figure 5).

Figure 5. Recommended 2020 Network, Montgomery County

Fig. 5 Recommended 2020 Network, Montgomery County

Source: Maryland-National Capital Park & Planning Commission (1999).

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