Fundamentals of Transportation/Mode Choice/Problem2

40px|left|TProblemProblem: Prior to the collapse, there were two modes serving the Marcytown-Rivertown corridor: driving alone (d) and carpool (c), which takes advantage of an uncongested carpool lane. The utilities of the modes are as given below. where t is the travel time Assuming a multinomial logit model, and A) That the congested time by driving alone was 15 minutes and time by carpool was 5 minutes. What was the modeshare prior to the collapse? B) How would you interpret the constant of -12 in the expression for Uc? C) After the collapse, because of a shift in travelers from other bridges, the travel time by both modes increased by 12 minutes. What is the post-collapse modeshare? Solution /Problems