Passenger car equivalent

Passenger Car Equivalent (PCE), is a metric used in Transportation Engineering, to assess traffic-flow rate on a highway. A Passenger Car Equivalent is essentially the impact that a mode of transport has on traffic variables (such as headway, speed, density) compared to a single car. For example, typical values of PCE (or PCU) are:

• private car (including taxis or pick-up) 1
• motorcycle 0.5
• bicycle 0.2
• horse-drawn vehicle 4
• bus, tractor, truck 3.5

Highway capacity is measured in PCE/hour daily

Passenger Car Equivalent is also sometimes used interchangeably with Passenger car unit (PCU).

A common method used in the US is the density method. However, the PCU values derived from the density method are based on underlying homogeneous traffic concepts such as strict lane discipline, car following and a vehicle fleet that does not vary greatly in width.