Question

As a transportation engineer, you are developing a model to manage the I-66 High Occupancy and Toll lane. The mode choices include 1) automobile drive-alone along parallel arterial streets (DL), 2) automobile drive-alone on I-66 with a toll (SOV), 3) automobile shared-ride on I-66 (toll free) HOV, and 4) express bus on I-66 B (also toll free). The utility functions are estimated:

??? = 2.2 − 0.1?????? − 0.02?????? ?????? ???? = 2.2 − 0.1??????? − 0.02?????? ??????? ???? = 0.8 − 0.1??????? − 0.03?????? ??????? ?? = 0.4 − 0.1????? − 0.01?????? ????? Where cost is in dollars and time is in minutes. Now let us ignore the cost for car maintenance and gasoline and assume the tolls and bus fares are the only cost component we will consider (therefore, cost for DL along arterial streets will be 0). During the morning peak, at one moment, the travel time from the Beltway to DC line along I-66 is 25 mins (no matter it is bus, SOV, or HOV), the travel time for the same origin and destination along US50 is 50 mins, the toll rate for SOV on I-66 is $10 and the bus fare is $3: a. What are the utilities for each mode? b. What are the percentage of travelers choosing different mode? c. If the toll rate is raised to $20 and travel time on both US-50 and I-66 remain unchanged, what is the new share for each mode? d. If the toll rate is still $10, because of an accident on US-50, the travel time along the arterial street becomes 70 minutes, what are the new share for each mode?

Answer 1