Assigning vehicles for transportation services

A method of determining whether to assign a vehicle without a driver to a trip, the method comprising:

• determining, by one or more processors, a route for a trip between a pickup location and a destination location for a passenger, the route including one or more lane changes;
• determining, by the one or more processors, branch routes for the route based on the one or more lane changes;
• determining, by the one or more processors, a probability of following each determined branch route;
• determining, by the one or more processors, a probability of requiring assistance for each determined branch route;
• determining, by the one or more processors, whether to assign a driver to the trip based the probability of requiring assistance for each determined branch route and the probability of following each determined branch route;
• and
• assigning, by the one or more processors, a vehicle of a fleet of vehicles to the trip based on the determination of whether to assign a driver.