A route is 15 miles long.

A mapping program says the drive should take 30 minutes.

So the bus should be able to make the trip in 30 minutes, right?

Not necessarily.

One of the fundamental differences between planning automobile travel and scheduling public transit is that a bus is not simply driving from Point A to Point B. It is providing service throughout the trip.

That changes everything.

What Is Running Time?

Running time is the scheduled amount of time a transit vehicle is given to travel between two locations while performing normal passenger service.

That includes much more than driving.

During a typical trip, the bus may:

• Stop dozens of times

• Load and unload passengers

• Wait at traffic signals

• Serve passengers using mobility devices

• Maneuver into transit centers

• Deal with congestion

• Merge back into traffic

• Make required turns

• Travel through school zones

• Cross railroad tracks

• Encounter construction or roadwork

Each event may add only a few seconds or minutes, but those minutes accumulate.

A 30-minute automobile trip may easily become a 45- or 50-minute transit trip.

Distance Is Only One Factor

Distance certainly matters. A 30-mile route generally requires more running time than a five-mile route.

But mileage alone tells us very little about how quickly a bus can actually operate.

Consider two ten-mile routes.

One travels primarily along a highway with widely spaced stops.

The other travels through a busy commercial corridor with traffic signals every few blocks and heavy passenger activity.

They may be nearly identical in distance but require very different schedules.

This is why simply calculating average speed from mileage can be misleading.

Passenger Activity Matters

Every boarding takes time.

A stop with one passenger may require only a few seconds. A stop with 15 passengers can take considerably longer.

Passenger activity also varies throughout the day.

A route serving a college may experience significant boarding activity immediately before and after classes. A route serving employment centers may be busiest during commute periods. Shopping areas may generate more activity during midday or weekends.

The schedule needs to reflect those patterns.

Otherwise, the bus may operate comfortably on some trips and struggle to remain on time on others.

Accessibility Is Part of Normal Running Time

Accessible service is not an unusual event. It is part of normal transit operation.

Boarding a passenger using a wheelchair or other mobility device may require deployment of a ramp, maneuvering into the vehicle, and securement.

That process takes additional time.

A schedule should not treat accessible boardings as something that never happens.

Good planning recognizes that passenger needs vary and builds reasonable operating time into the schedule.

Traffic Changes Throughout the Day

A trip that requires 35 minutes at 5:30 in the morning may require 50 minutes at 4:30 in the afternoon.

This is one reason using the same running time throughout the entire service day can be a mistake.

Transit planners often examine running times by different periods of the day.

• Early morning

• Morning peak

• Midday

• Afternoon peak

• Evening

The exact periods vary by agency and service area.

The objective is to recognize that road conditions are not constant.

Too Little Running Time

An overly aggressive schedule can create serious problems.

If the timetable does not provide enough running time:

• Operators begin arriving late

• Passengers miss connections

• Recovery time disappears

• Following trips begin late

• Dispatch must intervene more frequently

• Operators may feel pressure to rush

• On-time performance deteriorates

A timetable may look efficient because it minimizes travel time, but an unrealistic timetable is not efficient.

It simply transfers the problem to operations.

Too Much Running Time

Adding excessive running time is not the answer either.

If too much time is scheduled between timepoints, buses may arrive early and be forced to wait.

Passengers may experience slower trips than necessary.

Excessive running time can also increase the overall cycle time of the route and potentially require additional buses.

The objective is not to make the schedule as loose as possible.

It is to make it realistic.

Using Actual Operating Data

Modern transit systems collect substantial amounts of operational data.

Depending on the technology available, planners may be able to review:

• Actual departure times

• Actual arrival times

• Travel time between stops

• Dwell time

• On-time performance

• Passenger activity

• Traffic-related variation

This allows schedules to be developed from real operating conditions rather than assumptions.

Historical data can reveal that a particular segment regularly loses time during the afternoon or that another section consistently has more scheduled time than necessary.

That information can then be used during the next service change.

The 50th Percentile Is Not Always Enough

Suppose half of all trips complete a segment in 20 minutes or less.

Scheduling exactly 20 minutes may appear reasonable, but it means a significant number of trips will need more time.

Agencies may therefore examine higher percentiles when determining appropriate running time.

There is always a tradeoff.

Too low, and buses routinely fall behind.

Too high, and the timetable becomes unnecessarily slow.

The appropriate approach depends on the agency’s service standards and operating environment.

Running Time and Recovery Work Together

Running time and recovery time are related, but they are not interchangeable.

Running time should provide enough time to operate the passenger trip realistically.

Recovery time belongs at the end of the trip to absorb normal variation and allow the next trip to begin on schedule.

If a bus is consistently late at intermediate timepoints, simply adding more recovery at the terminal does not solve the passenger’s problem.

The trip itself needs to be examined.

Schedules Should Be Reviewed Regularly

Road conditions change.

New traffic signals are installed. Development occurs. Schools open. Construction begins. Passenger patterns shift.

A schedule that worked well three years ago may no longer reflect current conditions.

Running times should therefore be reviewed periodically rather than treated as permanent.

That does not mean changing the schedule every time one trip encounters unusual traffic.

The planner looks for patterns.

A single bad day is an incident.

A recurring problem is data.