Assess the Magnitude of Your Own Inefficiency

So given a system’s mission, its various constraints, and system features as outlined above, it’s nonetheless still useful to benchmark against some standard of efficiency. 4MATIV’s recommended back-of-the-envelope way to do this is by evaluating seat utilization on a bus trip against a theoretical maximum that considering the configuration of bell tiers.

1. Calculate Seat Utilization
   A typical Type C bus (a standard yellow bus) has a stated “manufactured capacity” of 68-77 passengers. That assumes students sit three-per-seat, which is impracticable for older students and often unrealistic even with the smallest students. So a better guidepost – and one that makes the math simple – is to assume most full-sized buses can fit 50 students. This is about two per seat and results in a very full bus (especially according to most drivers).

   For each increment of 50 students in a school or school system, the most efficient way to transport those students would be to run one bus. Assuming just one bell tier, 100 students would require two buses, 150 students would require three buses, and so on. If a system transports 50,000 students with one bell tier, then the back-of-the-envelope calculation would indicate a need for 1,000 buses. If a system is currently running more than that, then that system can be made more efficient.

   Unfortunately, that calculation doesn’t indicate anything about how long the trips might be or how far students have to walk to bus stops. For example, if a district has widely disparate geographies that it’s trying to serve and adopts a (reasonable and sometimes non-negotiable) restriction on how long students should ride on a bus, then picking up 50 students within even a loosely “reasonable” but still long bus ride time (say, 90 minutes or less) may not be possible, even if “community” or “hub stops” are used.

2. Include Bell Times
   Another enormous lever whose impact can be calculated fairly simply in tandem with the above seat utilization calculation are bell times. For instance, in a district with two schools that each need to transport 50 students, two buses will be required if their bell times are the same. If the bell times are staggered (to allow at least, say, 60 minutes in between), then one bus (with the max of 50 students on each trip) could be “stacked” or “tiered” and serve all 100 students. A three tiered system could similarly serve 150 students with one bus if school schedules were staggered with 60 minutes (sometimes in smaller geographies this doesn’t have to be such a tight window).
3. Find the Theoretical Maximum
   In this way, a school system can quickly calculate the theoretical minimum number of buses needed to serve their system if they could freely adjust the bell times, set reasonable or defensible walk-to-stop distances, and pick up 50 students on each trip within the time allotted. The “theoretical” maximum efficiency calculated might not practically be achievable for reasons of geography (not enough time to traverse an area), neighborhood safety, or socioeconomic reasons (parents can’t or won’t get to or have students walk to far-flung bus stops), but it’s still a useful guidepost.
4. Evaluate System Fidelity
   Another way to think about and assess efficiency is assessing a system’s fidelity and adherence to existing published walk zones, eligibility boundaries, and walk-to-stop distance guidelines. In theory, a maximally efficient system would adhere to these policies without exception. Exceptions that are left should be understood, codified, and systematically reevaluated periodically. Walk-to-stop efficiency and stop consolidation specifically as a strategy to enhance efficiency is the subject of another paper.