Why the Bus Type Matters to the Schedule

A transit agency has an available bus.

A trip needs a bus.

Problem solved?

Not necessarily.

Modern transit fleets can contain several vehicle types, and each may have different operating characteristics.

Capacity

The most obvious difference is passenger capacity.

A heavily used trip may require a larger bus.

Assigning a smaller vehicle may result in:

• Overcrowding
• Passengers being passed up
• Longer boarding times

Vehicle assignment therefore begins with expected demand.

Vehicle Length and Geometry

Not every roadway or terminal works equally well for every vehicle.

A longer bus may have difficulty with:

• Tight turns
• Small turnaround areas
• Narrow streets
• Limited bus bays

The schedule and route design need to reflect the physical vehicle.

Conventional Fuel Range

Diesel and other conventionally fueled buses also have range considerations, although agencies have historically been able to refuel them relatively quickly.

Long blocks still require enough fuel to complete the assignment with an appropriate reserve.

Battery-Electric Buses

Battery-electric buses add more variables.

Range can be affected by:

• Block mileage
• Temperature
• Air conditioning
• Heating
• Elevation
• Passenger load
• Traffic
• Driving conditions

The advertised maximum range of a bus should not automatically be treated as the planning range for daily service.

Operational reserve is important.

Charging

Charging also takes time.

A block may be designed around:

• Overnight charging
• Midday charging
• Opportunity charging

If the bus must charge during the service day, the charger itself becomes part of the operating plan.

It has to be:

• Available
• Working
• Located where the bus can reach it
• Scheduled for enough time

Hydrogen Fuel-Cell Buses

Hydrogen fuel-cell electric buses may offer different range and fueling characteristics.

They still require appropriate fueling infrastructure and operational planning.

A mixed zero-emission fleet therefore does not mean every zero-emission bus can automatically substitute for every other one.

Assign the Vehicle to the Block

The correct way to evaluate a bus is generally against the entire block.

A bus might easily operate one 20-mile trip.

That does not mean it can operate a 220-mile daily block containing that trip.

Planners need to consider:

• Revenue mileage
• Deadhead
• Recovery
• Fuel or energy reserve
• Charging or fueling opportunities