Case Study:

Sacramento, California

Application

Comparison of MEPLAN and SACMET96 Results

A comparison between the results produced by SACMET96 and MEPLAN suggests the contribution of land use modeling to the identification of travel impacts. As noted above, the scenarios simulated in SACMET96 differ somewhat from the scenarios simulated in MEPLAN. Thus, the contribution of the land use modeling cannot be fully isolated from the effects of the differences in the models and scenarios. However, some rough comparisons can be drawn:

• The HOV-only scenarios are roughly comparable (Figure 16). While SACMET96 predicts an increase in total VMT, MEPLAN predicts a much larger increase. This may be a result of households and employment relocating to take advantage of the greater highway capacity and reduced travel times provided by the HOV-lane expansion.

• The transit/TOD scenarios are roughly comparable (Figure 18), although (as noted above), the concentration of employment and population in TODs is not as great in MEPLAN as in SACMET96. MEPLAN produces a significantly greater mode shift from drive alone to transit. MEPLAN also forecasts a reduction in auto trips consistent with the mode shift, but the forecast reduction in VMT is smaller, suggesting that the remaining auto trips are longer on the average.

• The magnitude of change in the policy scenarios compared to the base case is generally greater in the MEPLAN scenarios than in the SACMET96 scenarios. This may be due to the positive feedback between accessibility and land use in MEPLAN.

Figure 16.
SACMET96 vs. MEPLAN Model
Travel and Mode Share: Change from Base Case (2015)

Source: Johnston, Rodier, Choy, and Abraham (2000).

Figure 17.
SACMET96 vs. MEPLAN Model
Travel and Mode Share: Change from Base Case (2015)

Source: Johnston, Rodier, Choy, and Abraham (2000).

Figure 18.
SACMET96 vs. MEPLAN Model
Travel and Mode Share: Change from Base Case (2015)

Source: Johnston, Rodier, Choy, and Abraham (2000).

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