Dead mileage routinely occurs when a bus route starts or finishes in a location away from a bus garage or out-station, and the start or end of a shift requires driving the bus to and from the garage out of service. Dead mileage can also occur in cases where shift-break parking has to be undertaken in terminii away from the service route.
Dead mileage incurs costs for the operator in terms of non-revenue earning fuel use, wages, and a reduction in the utilisation of the driver's legal hours of driving.
Operators will often reduce dead mileage by starting or finishing the first or last service of the day, or shift, at a garage along the route, a so called part service or part route. Dead mileage may also be reduced by the operation of routes specifically timed and routed to facilitate bus movements rather than passenger need.
Dead mileage has increasingly become an issue with privatised competition for bus services, most notable with the privatisation of London bus services, where competing operators have to factor on the cost of dead mileage when bidding for specific routes away from their main garages. This is exacerbated by not being allowed to operate a service that may match the dead mileage route. This can be lessened to an extent by tendering routes in groups of sufficient size to justify opening/renting new garage space.
Often operators will come to an arrangement to share garage facilities to reduce dead mileage.