$($a$)$ Give one example of land use$-$transportation interaction. Explain the effect of such interaction on travel demand.

$($b$)$ Consider prediction of travelers' route choice on travel time using a multinomial logit $($MNL$)$ model. However, If two or more routes are overlapped, the MNL model may yield unrealistic results of route choice due to the assumption of the models. Explain why the MNL model may not be valid in this case and how the limitation of the assumption in the model can be ovecome.

$($c$)$ Describe the difference between a supply$-$side solution and demand$-$side solution for transportation problem. Provide one example for each.