The empty car travel often referred to as "dead mileage" is the trip from a Base to Pick up and from Drop off to Base as well.

You may wish to charge for these trips and you can set this up at the back end.
Go to Dashboard > Settings > Base settings
Set up Base coordinates (latitude and longitude) - for your convenience you can click on Get coordinates link and a location pin will appear in the Map, move the pin to your exact base location and the system will automatically fetch the coordinates of the pin.
Base to Pick up calculation: Yes/No - this is the setting that tells the system to calculate the distance and time from Base to Pick up address.
Use for Fixed fare routes: No - Base to Pick up will not be calculated in Fixed fare routes.
Use for Fixed fare routes: Time only - Only the time needed to get from Base to Pick up address will be considered to block off Car availability and avoid double bookings when en-route. 
Use for Fixed fare routes: Both Price and Time - time needed will be considered as well as a charge for the trip while empty.
Base to Pick up Charge: Flat rate - a flat fee to charge for Base to Pick up regardless of the distance.
Base to Pick up Charge: Price per mile - calculate the charge based on mileage to Pick up
Value: - monetary value for Base to Pick up charge.
Charge if Base to Pick up over: here you can set up when the above calculations will be triggered based on distance from Base to Pick up.

Drop off to Base calculation: Yes/No - all options and settings for Drop off to Base will be available with the same set up as above Base to Pick up.