What characterizes a private hire vehicle compared to a taxi?

A private hire vehicle is defined by its operational limitations, primarily in that it cannot accept passengers who flag it down off the street. This distinction is crucial because private hire vehicles must be pre-booked through a licensed operator, which differentiates them from taxis that can pick up passengers without a prior reservation. This requirement ensures that the demand for private hire vehicles is managed through established bookings and helps maintain regulatory oversight for safety and service standards.

The other options do not accurately portray the key characteristics that define private hire vehicles. Safety regulations for private hire vehicles are generally stringent, not fewer than those for taxis. Additionally, private hire vehicles are not required to display a 'Taxi' sign, which is exclusive to taxis. Lastly, private hire vehicles can operate across multiple districts as long as they are licensed appropriately, rather than being restricted to a single district. Thus, the correct answer emphasizes the critical aspect of pre-booking for private hire vehicles.