One of the most consequential decisions in transit scheduling—how running time is defined and applied—often receives far less deliberate attention than it deserves. Choices between fixed or incremental running time, and between arrival-based or departure-based scheduling, quietly shape service reliability, labor costs, operator experience and customer trust. Yet at many agencies, these decisions are inherited rather than examined, made by default rather than by design.
Understanding the practical implications of these approaches builds confidence in scheduling decisions, which is essential for effective operations and credible customer service. When these choices are misunderstood or oversimplified, agencies may inadvertently trade reliability for appearance or operational resilience for ease of production. This article explores the real-world advantages and disadvantages of commonly used running time and timing strategies, and why they matter more than many agencies realize.
Schedulers, runcutters and roster makers often say, “I’ve been doing this job for years, and I’ve never heard it explained this way.” That reaction is understandable. Many professionals learn scheduling by inheriting established practices and applying them consistently, sometimes without having the opportunity to step back and examine the underlying assumptions.
I was fortunate to receive early training in a department with deep institutional knowledge, learning scheduling by hand before relying on software. Even with decades of experience, I continue to learn and refine my thinking because scheduling, when done well, is both a technical discipline and a human one.
It is worth stating plainly: Scheduling software is a tool, nothing more. Knowing how to operate a system does not automatically confer scheduling expertise, just as knowing how to use a word processor does not make someone a novelist. Judgment comes first; the software records decisions after they are made.
When agencies blur that distinction, they risk confusing technical proficiency with operational understanding, and the consequences are felt by operators on the street and customers at the stop.
With that foundation, this discussion begins with a fundamental choice: whether schedules are built around arrivals or departures and how that decision influences behavior across the system. From there, it examines fixed versus incremental running time, highlighting how each approach performs under real operating conditions. The goal is not to advocate a single universal solution, but to help agencies understand the trade-offs involved so that choices are made intentionally, with eyes open to their operational consequences.
About the Author
Ed Dornheim
Consultant
Ed Dornheim is expert transit scheduler with decades of experience beginning with the Southeastern Pennsylvania Transportation Authority (SEPTA) as a part-time Traffic Checker. He worked in various roles at SEPTA along with two stints in scheduling ending as a Chief Schedule Maker, as well as working as the Scheduling Manager at Hampton Roads Transit (HRT) and Scheduling and Planning Manager at Lehigh and Northampton Transit Authority (LANTA).
He began consulting in 2015 with various transit agencies across the United States and Canada.