Variable

Best Estimate

Sensitivity Test Range

Minimum Performance to Achieve the 4% PM10 Emission Reduction Target

Sensitivity Tests Result (Change in % Emission Reductions)

Failure cut-points

75% of the baseline emission rates

60% - 100% of the baseline emission rates

N/A

11.1% - 9.8%

Program participation rate

90%

0-100%

>30%

0.6% - 11.7%

Problem vehicle identification rate

50%

>17%

0.6% - 20.6%

Effectiveness of failed vehicle repairs

Percent of repair work initially effective

72%

>22%

1.1% - 14.3%

Percent of excess emissions reduced by good repairs

81%

>25%

1.1% - 12.9%

Percent of good repairs that remain durable

86.5%

>26%

1.1% - 12.1%

Failed vehicle illegal operation rate

10% for buses and heavy trucks; 20% for light trucks and motorcycles

<75%

1.1% - 12.6%

Vehicle population growth

10% decrease in average annual growth rate under the baseline scenario

0% - 30% decrease in average annual growth rate

N/A

10.1% - 11.6%