An approach is provided for managing a vehicle reservation used in an intermodal route. A routing platform determines that the intermodal route includes a segment to be traveled using a vehicle booked via the vehicle reservation, and another segment that is traveled using a different mode of transport for a user to reach the vehicle to travel the segment. The routing platform monitors an expiration period of the vehicle reservation and a user location of the user on the another segment. The routing platform calculates a probability that the user will reach the vehicle to travel the segment before an end of the expiration period based on the user location. The routing platform generates at least one route option based on the probability, wherein the at least one route option includes an extension the vehicle reservation, and/or a creation of another vehicle reservation for another vehicle.